# Me 209 - any worth in it?



## tomo pauk (May 23, 2015)

I'm trying to acquire some good data on the Me 209, the fighter prototype with roots in the Bf 109. For the starters - the data in Wikipedia varies depending what language one reads


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## l'Omnivore Sobriquet (May 23, 2015)

Me-209 or Fw-190C2, that's the question..


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## Shortround6 (May 23, 2015)

Me 209







Or Me 209






*THAT* is the question


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## l'Omnivore Sobriquet (May 23, 2015)

The fighter prototype I guess.


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## tomo pauk (May 23, 2015)

As in the 1st post - the fighter, not the racer


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## l'Omnivore Sobriquet (May 23, 2015)

My mistake, a quick check on Wiki tells me it was fitted with the Jumo 2013 and not the Db-603 as I thought it was. (or else?)
So no comparison with Fw-190C.
But with the D. Which was prefferd as we know, righfully it seems.
Would love some more info on the 209 beyond its "unfavourable" performance, and the good decision to go with the Me-262 alone, instead...


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## davebender (May 23, 2015)

Shortage of DB603 engine program funding wrecked several promising airframe programs. Original DB powered design for Fw-190, Do-217 bomber, Me-209II, Me-309, Me-410 etc.


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## Denniss (May 23, 2015)

The depicted image does not show a Jumo-equipped Me 209 fighter - no engine air intake on the right cowling


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## Shortround6 (May 23, 2015)

Another problem for the 209II was the anticipated 65% common parts with the 109G making conversion of existing production lines easy fell to 40% common parts or less as the project advanced. With less performance than promised and a higher cost of conversion (both in new tooling and lost production) the 209IIs fate was sealed.


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## kool kitty89 (May 23, 2015)

It seems to me that putting all the test engines, material resources, and funding that went to the Me 309 and 209 II into developing Fw 190 derivatives using the DB 603 and 605 would have made much more sense in practical, production/manufacturing, and operational terms.


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## Jaivan (May 24, 2015)

Mtt AG also tried to do a fighter from the racer a fighter, unsucesfully 

The problem with the second incarnation (Me 209 "II") is that there isn't many primary sources neither for its flying qualities nor its performance, so anything written about it (V5, V6 or V7) must be taken with a grain of salt.


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## davebender (May 24, 2015)

Therein lays the rub. 

RLM cancelled DB603 funding during 1937 after only a single year of development. Partial funding was grudgingly restored during 1940 but RLM never put their full support behind DB603 engine development and mass production. So DB603 powered Fw-190s are no more likely then DB603 powered Me-209 or Me-309.


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## kool kitty89 (May 25, 2015)

davebender said:


> Therein lays the rub.
> 
> RLM cancelled DB603 funding during 1937 after only a single year of development. Partial funding was grudgingly restored during 1940 but RLM never put their full support behind DB603 engine development and mass production. So DB603 powered Fw-190s are no more likely then DB603 powered Me-209 or Me-309.


Plus, the DB-601 and 605 were hard pressed to be allocated to new (particularly non-messerschmitt) projects, so Fw 190 derivatives using those powerplants would likely require a different political situation. Though I'm not aware if Focke Wulf ever seriously attempted to allocate 601/605 engines for testing, it seems like the original small-wing 190 would have been better matched to the 601 at its inception and lacked the teething troubles of the BMW/Bramo radials.


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## razor1uk (May 26, 2015)

Denniss said:


> The depicted image does not show a Jumo-equipped Me 209 fighter - no engine air intake on the right cowling



It might not be the Jumo powered one in that pic, but the annular mixed water oil cooler are certainly connected with typically later Jumo's were shared between later engines of either manufacturer.


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## l'Omnivore Sobriquet (May 26, 2015)

Not developping or "freezing" the big Db-603 at an early stage was not a bad decision in itself nor even bound to be a bad one. There were short term war urgencies by the late 30's and it is just like Britain's RR decision to "freeze" the RR Griffon for a while. Quite sound in the days.
What was bad was Germany's decision makers somehow listening to themselves and keeping that decision way out of time. They just stuck to it far too long. In my view because of over-confidence, just enhancing their previous judgements for the sake of it. The Brits were more 'flegmatics' (is the word ok?) about it all.
Obviously Daimler's Db-603 ran into silly conservative behaviour and opporunities were missed.
Really by a hair-thin margin.


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## davebender (May 26, 2015)

Two bad decisions but IMO cancelling DB603 was the worst since it was essentially just an enlarged DB601 and already had a 1,500hp prototype running.


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## zoomar (May 26, 2015)

The "original" Me209 developed from the high-speed record machine would have been a non-starter. The Me209II was a reasonably effective development of the Bf109 series, so it's the only one that merits serious discussion. The problem for Messerschmitt was that Fw190/Ta152 series of fighters were already in development, and these offered the same general performance that the Me209II. Unlike the USA, which had the design and manufacturing capacity to produce a number of different aircraft for basically the same role, Germany did not have that luxury. The RLM was just not going to spend money on a heavily modified development of the Bf109 when it could get basically the same performance from existing Bf109s and the soon-to-be available Fw190D and Ta-152. Coupled with the abject failure of the entirely new Me309, Messerschmitt had by this time frozen itself out of the piston-engine fighter business. The future for Messerschmitt lay with the Me262 and other jets.

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## davebender (May 26, 2015)

> Coupled with the abject failure of the entirely new Me309, Messerschmitt had by this time frozen itself out of the piston-engine fighter business



Me-309 development effectively ended during 1942 after a mere four prototypes. How can anyone call that an "Abject failure"? Development was cancelled before the aircraft had a chance to prove itself powered by DB603 engine for which it was designed.

During 1943 to 1945 (i.e. after Me-309 funding cancelled) Messerschmitt produced more then 20,000 Me-109s. That doesn't meet my definition of "frozen out of piston engine fighter business". To the contrary it appears Luftwaffe was pleased with performance and low cost of late war Me-109 variants.


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## Shortround6 (May 26, 2015)

davebender said:


> DB604 took priority over DB603. Jumo222 took priority over Jumo213.
> Two bad decisions but IMO cancelling DB603 was the worst since it was essentially just an enlarged DB601 and already had a 1,500hp prototype running.



A lot depends on timing. The small cylinder but many cylindered engine has several advantages over a large cylinder engine. 
1. The small cylinders offer better cooling. Both due to a higher cylinder wall to volume ratio and and a shorter path for the heat to travel from center of piston to cylinder walls. This allows for higher compression or higher boost than the big cylinder engine can use. 
2. The smaller reciprocating parts allow for higher rpm. The DB 604 could turn about 18% more rpm than the DB 603. 
3. The smaller cylinders _should_ show higher volumetric efficiency than large ones.

For any given grade/PN number fuel the high rpm small cylinder/multi cylinder (over 12 in the case of inline or V engine) _should_ show a marked advantage over the large cylinder 12. 
However there are also a number of disadvantages to the layout/s and the large 12s did NOT stay frozen in time. 
Comparing a 1943/44 large 12 to a 1940/41 24 cylinder engine ignores some of the progress made in rings, bearings, piston design and other aspects that helped close the gap. Scaling up only works to a certain extent. Changing the stroke from 160mm to 180mm and keeping the smaller engines rpm means about a 26% increase in loads on the rod bearings and main bearings just from the change in piston speed and doesn't take into account the increased weight of the bigger rods and pistons. Granted the scaled up engine has larger bearings but are they large enough? 
In the late 30s many engine designers/companies thought they could _just_ add cylinders or adopt complex engine layouts with little more trouble than they had with the lower number of cylinders. Time proved them wrong. But without the aid of the retrospectroscope it is a lot harder to find fault with them. If all you have is 87 octane fuel you run into limits on how much power you can get from a certain size cylinder pretty quick. The size of the cylinder helps dictate engine rpm. The common V layout was 12 cylinders so the basic limits were pretty well known. 
The ways out included better fuel for higher boost/compression. Higher RPM which required better bearings and a _much_ better understanding of harmonic vibration. Or going the 16-14 cylinder route.

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## wuzak (May 26, 2015)

The DB604 was substantially more powerful than the DB603.

T/O/Max Power
DB603A: 1,750hp @ SL, 1,850hp @ 6,900ft, 1,625hp @ 18,700ft
DB604: 2,660hp @ SL, 2,410hp @ 20,600ft

Climb Combat
DB603A: 1,575hp @ Sl, 1,675hp @ 6,900ft, 1,520hp @ 18,700ft
DB604: 2,270hp @ SL, 2,120hp @ 21,000ft

Max Cruising
DB603A: 1,375hp @ SL, 1,450hp @ 6,900ft, 1,400hp @ 17,700ft
DB604: 1,830hp @ SL, 1,860hp @ 20,000ft

The DB604 did weigh more, by about 400lbs. 20% more weight for 30%+ more cruising power, ~40% more climb/combat power and ~50% more take-off/maximum power. From 4% greater capacity.

GED0109
GED0106


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## Juha (May 27, 2015)

davebender said:


> ... To the contrary it appears Luftwaffe was pleased with performance and low cost of late war Me-109 variants.



I really doubt that the LW was pleased with performance of 109G-6 during the early part of 1944, numerically inferior LW would really needed something better, in the late summer 44 arrived the partial solutions (G-14 and G-6/AS) which somewhat easied the quality problem but not enough to solve the quantity problem.

Germans produced massive amount of 109G-6s because they had not anything better at that time, not because they were very satisfied with it anymore.

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## Greyman (May 27, 2015)

Juha said:


> Germans produced massive amount of 109G-6s because they had not anything better at that time, not because they were very satisfied with it anymore.



That's basically what Generalleutnants Galland and Schmid said during postwar interrogation as well. 

_"Our technical development program was not planned far enough into the future ... This was a mistake of tremendous scope. For example, the Me 262, the further development of the Fw 190, the gyro computing sight, engines of more than 2000 hp and many other developments were thus all delayed.

In the effort to raise production figures of items in series production, new developments were not forced into series models with the necessary pressure ... In addition, there was a certain dangerous (and partly unwarrented) self-satisfaction at every new technical advance.

For this reason the Me 109 was not taken out of series production for years, although this was absolutely necessary on the basis of performance figures from 1943 on. Similarly the beginning of the new series of Fw 190 and of the Ta 152 was so delayed as to be almost ineffective."
_
In their ideal scenarios there would have been a faster conversion to the Fw 190 and less use of the Me 109 in 1942, replacement of the Me 109 introduced in 1943, and complete phase out by 1944.

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## yulzari (May 27, 2015)

Shortround6 said:


> A lot depends on timing. The small cylinder but many cylindered engine has several advantages over a large cylinder engine.
> 1. The small cylinders offer better cooling. Both due to a higher cylinder wall to volume ratio and and a shorter path for the heat to travel from center of piston to cylinder walls. This allows for higher compression or higher boost than the big cylinder engine can use.
> 2. The smaller reciprocating parts allow for higher rpm. The DB 604 could turn about 18% more rpm than the DB 603.
> 3. The smaller cylinders _should_ show higher volumetric efficiency than large ones.


rt
Hence the Napier Dagger whose air cooling problems and solutions were identified too late to be used.


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## Shortround6 (May 27, 2015)

The Dagger threw in the change from liquid cooling (old Lion) to air cooling. But yes, the _concept_ of using many small, fast running cylinders was there. And shows some of the advantage, it's short stroke (95.5mm) cylinders allowed it turn 4200rpm at the same piston speed as a DB 601 turning 2400rpm. It used a 7.5 compression ratio at the same 6lbs boost that the larger cylinder Merlin used but at a 6.0 compression ratio using 87 octane fuel.


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## davebender (May 27, 2015)

During early 1944 USA was flying P-51B and early model P-47s. Many RAF squadrons were still flying Spit V. 

DB605 engine technical problems were finally fixed and water injection was being introduced. I don't think German aircraft performance was a problem. The real issue was a huge fuel shortage for operations and pilot training.


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## Juha (May 27, 2015)

davebender said:


> During early 1944 USA was flying P-51B and early model P-47s. Many RAF squadrons were still flying Spit V.
> 
> DB605 engine technical problems were finally fixed and water injection was being introduced. I don't think German aircraft performance was a problem. The real issue was a huge fuel shortage for operations and pilot training.



But most of those Spit sqns within range of Continental Europe were flying Spit VII, IX or XII. And MW system seems to have been very rare with 109G-6s, when it became common the plane was called 109G-14 and the time was mid-44. And P-51B was definitely faster than G-6 at altitudes used by 8th AF bombers.

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## davebender (May 27, 2015)

Most German daytime aerial combat took place at 2,000 meters. An altitude where standard model Me-109G6 was right at home.

JG2 and JG51 should have gotten high altitude engines but high altitude engines would have been pointless for most Me-109Gs.


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## bobbysocks (May 27, 2015)

2000 meters??? think your finger slipped or something...might want to triple or quadruple that. 2000m is about 7000 feet. in the beginning fighters were not allowed to leave the bombers....after doolittle changed things..it still started at bomber height but fighting was all over the place and usually ended up on the deck.


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## Juha (May 27, 2015)

davebender said:


> Most German daytime aerial combat took place at 2,000 meters. An altitude where standard model Me-109G6 was right at home.
> 
> JG2 and JG51 should have gotten high altitude engines but high altitude engines would have been pointless for most Me-109Gs.



Bad thing was that it was the best altitude for La-5F and La-5FN but the best altitude for 109G-6 was higher, at 5 - 7 km.


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## GrauGeist (May 27, 2015)

davebender said:


> ...but high altitude engines would have been pointless for most Me-109Gs.


I will assume this is reference to the Eastern front air war, because the airwar over the western front could range from treetop level to roughly 5 miles high...

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## Shortround6 (May 27, 2015)

davebender said:


> During early 1944 USA was flying P-51B and early model P-47s. Many RAF squadrons were still flying Spit V.
> 
> DB605 engine technical problems were finally fixed and water injection was being introduced. I don't think German aircraft performance was a problem.



Hmmm, In Nov 1943 water injection is being fitted to P-47D-20s on the production line and modification kits are being fitted to "older" aircraft in England. Most aircraft are refitted by the end of 1943. 
Dec, 1943 sees "older" P-47s in England being refitted with paddle-blade props, one squadron at a time. Wonder how the 109G-6 does against an "old" P-47 with water injection and a paddle-blade prop? 
First "early" P-47Ds showed up in England May of 1943 and by June were in service with 3 different fighter groups in the 8th Air Force even if not fully replacing P-47Cs.
In Feb 1944 preparations were being made to increase boost on existing engines in the field from 56in MAP to 64in MAP by refitting the water injection system with large jets and modifying other parts (fuel pumps, water pumps and turbo regulators) 
But the 109s should have _no_ trouble dealing with such "early model" aircraft...... right?


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## dedalos (May 28, 2015)

The Me 209 II was not a good investment
It required a large engine to have decent performance. Germany already had the 190 to use the jumo 213 and db603.(And still barely such vertions entered service)
What germany needed by a replacement of the 109 was a fighter able to achieve better performance, posses better handling,carry more fuel, mounting at least 2 Internal 20 mm cannons USING THE DB605. It would be unacceptable to waste alll this production capacity of the db 605.Could be done? The italians did it. All 3 series 5 italian fighters appear to make much better use of the Db605 than the Bf109. German should only try to make them easier to produce


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## tomo pauk (May 28, 2015)

Better handling on greater fuel means a bigger wing is needed. This is what Italian fighters achieved (at least the G.55 and Re.2005). Bigger wing also means lower speed, as it can be seen when we compare the Series 5 fighters one with another and then with Bf 109. 109 was fastest, along with MC.205N, but MC.205N could not carry the 2 cannons in the wings. Hence the MC.205V, with bigger wing, cannons, and also some 10 km/h speed loss. 
Basically, there ain't such thing as a free lunch.

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## dedalos (May 28, 2015)

tomo pauk said:


> Better handling on greater fuel means a bigger wing is needed. This is what Italian fighters achieved (at least the G.55 and Re.2005). Bigger wing also means lower speed, as it can be seen when we compare the Series 5 fighters one with another and then with Bf 109. 109 was fastest, along with MC.205N, but MC.205N could not carry the 2 cannons in the wings. Hence the MC.205V, with bigger wing, cannons, and also some 10 km/h speed loss.
> Basically, there ain't such thing as a free lunch.



I am not sure. All series 5 fighters appear to be much cleaner than the Bf 109 and with more advanced wing profiles. The inferior speed of the tests could be result of derated italian DB 605s plus inferior propellers.
If you add under wing guns in to 109 to have the same armament as the italian fighters ,the 109 is clearly inferior. Also with their greater fuel capacity the series 5 fighters can operate at higher power levels longer than the 109.
Finally with their overall bigger size could recieve easier additional cooling devices to allow more powerful vertions of the DB605


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## EKB (May 28, 2015)

davebender said:


> DB605 engine technical problems were finally fixed and water injection was being introduced. I don't think German aircraft performance was a problem. The real issue was a huge fuel shortage for operations and pilot training.




_“ In the five years between between the Battle of Britain and the end of World War II, the number of hours that an Me 109 engine could be run without major work decreased from 100 to 10.”_

Johannes Steinhoff
JG 77

See p.236 
Philip D. Caine. *Eagles of the RAF* (Washington, D.C.: National Defense University Publications, 1991).



_" I should point out the enormous problems caused by the unreliability of our supercharged Daimler-Benz 605 AS engines. They would barely make it beyond the fateful 50 hour mark ... In my Staffel, it was frequently the case that engines would have to be changed two or three times before finding one which ran satisfactorily ... We were astonished to read in 'Interavia' that the Russians had complained to the Americans that the engines that had been supplied had a life of only 300 hours instead of the 350 hours promised!”_

Karl Mitterdorfer
JG 300

See p.325-326
Lorant, Jean-Yves and Richard Goyat. *Jagdgeschwader 300 "Wilde Sau": A Chronicle of a Fighter Geschwader in the Battle for Germany. Volume One, June 1943 - September 1944* (Hamilton, MT: Eagle Editions, 2005).



_" Low oil pressure plagued the DB 605 engine throughout its operational career. Daimler-Benz maintained that the horseshoe oil tank was at fault while the Messerschmitt people claimed that the hydraulic supercharger trapped air bubbles in the oil. Eventually the DB people developed and installed a de-aerator but when no improvement was found the de-aerator was discarded. The oil pressure problem was never satisfactorily solved.”_

See p.17
Beaman, John. *Messerschmitt Bf 109 in Action, Part 2* (Carrollton, TX: Squadron-Signal, 1983).


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## Milosh (May 28, 2015)

LOL EKB. You just made a friend of a Hungarian lawyer, NOT.


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## kool kitty89 (May 29, 2015)

Greyman said:


> That's basically what Generalleutnants Galland and Schmid said during postwar interrogation as well.
> 
> _"Our technical development program was not planned far enough into the future ... This was a mistake of tremendous scope. For example, the Me 262, the further development of the Fw 190, the gyro computing sight, engines of more than 2000 hp and many other developments were thus all delayed.
> 
> ...


Given who it was who made those remarks, I assume they were most heavily leveled from the perspective of experienced pilots and raw aircraft performance. The Fw 190 had the additional advantages over the 109 in easier handling on the ground and in the air, reducing accidents for all but especially novice pilots.





Shortround6 said:


> Hmmm, In Nov 1943 water injection is being fitted to P-47D-20s on the production line and modification kits are being fitted to "older" aircraft in England. Most aircraft are refitted by the end of 1943.
> Dec, 1943 sees "older" P-47s in England being refitted with paddle-blade props, one squadron at a time. Wonder how the 109G-6 does against an "old" P-47 with water injection and a paddle-blade prop?
> First "early" P-47Ds showed up in England May of 1943 and by June were in service with 3 different fighter groups in the 8th Air Force even if not fully replacing P-47Cs.
> In Feb 1944 preparations were being made to increase boost on existing engines in the field from 56in MAP to 64in MAP by refitting the water injection system with large jets and modifying other parts (fuel pumps, water pumps and turbo regulators)
> But the 109s should have _no_ trouble dealing with such "early model" aircraft...... right?


Given the added weight and drag on later P-47 models, wouldn't retrofitted C and (especially) Early D models have BETTER performance than later models, particularly ones lacking the expanded fuel capacity and wing pylons. (sure it limited operational range and bombload, but IF they came into contact with 109s, they'd be more potent fighting machines aside from the poorer situational awareness of the razorback configuration retaining the birdcage canopy -still better visibility than the 109G)





dedalos said:


> I am not sure. All series 5 fighters appear to be much cleaner than the Bf 109 and with more advanced wing profiles. The inferior speed of the tests could be result of derated italian DB 605s plus inferior propellers.
> If you add under wing guns in to 109 to have the same armament as the italian fighters ,the 109 is clearly inferior. Also with their greater fuel capacity the series 5 fighters can operate at higher power levels longer than the 109.
> Finally with their overall bigger size could recieve easier additional cooling devices to allow more powerful vertions of the DB605


Given the overall size, weight, and armaments carried, wouldn't a DB-605 powered Fw 190 derivative (particularly with the lighter, earlier A models as the basis) have a lot in common with the G.55, and especially R.2005? (possibly MC.205 if you go back to the older, smaller wing of Fw 190 prototypes and early A-0 airframes, or MC.202 with the DB-601)

The He 100 with a longer span wing would be closer to the Italian fighters. (a modification that would have been pretty much inevitable had the design actually continued development) Granted, Heinkel's focus on racing/speed record goals for the He 100 didn't expedite more practical development progress for the design either.


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## kool kitty89 (May 29, 2015)

Shortround6 said:


> A lot depends on timing. The small cylinder but many cylindered engine has several advantages over a large cylinder engine.
> 1. The small cylinders offer better cooling. Both due to a higher cylinder wall to volume ratio and and a shorter path for the heat to travel from center of piston to cylinder walls. This allows for higher compression or higher boost than the big cylinder engine can use.
> 2. The smaller reciprocating parts allow for higher rpm. The DB 604 could turn about 18% more rpm than the DB 603.
> 3. The smaller cylinders _should_ show higher volumetric efficiency than large ones.


In this regard (and in terms of the X layout) the DB-604 is rather like Rolls Royce's Vulture, with the DB-603 more akin to the Griffon (or R), though Development priority at Rolls Royce proceeded a fair bit differently.

I do wonder if a V-16 arrangement would have been any easier to work with, more a compromise between larger displacement V-12s and more complex multi-bank configurations. (plus should have lower frontal area than similar displacement V-12s, X-24s, or H-24s)
An inverted V-16 using the DB-601's bore and stroke would have given slightly higher volume than the 603 and (in theory) significantly better volumetric efficiency at given compression/boost and fuel grade as well. (ideally, similar or better than what the DB-601 managed)


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## wuzak (May 29, 2015)

The DB 609 was essentially a V-16 version of the DB 603. It had similar power to the DB 604, but using larger capacity (62l vs 46l) and heavier weight.

V-16s will be longer than an equivalent V-12. The length of the crankshaft and camshafts potentially cause problems. That's why the Chrysler IV-2220 used a central gear drive, essentially making the engine two V8s. 

The DB 609, however, had the power take-off at the front.

The frontal area will be lower, but the length will be greater.

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## Shortround6 (May 29, 2015)

kool kitty89 said:


> In this regard (and in terms of the X layout) the DB-604 is rather like Rolls Royce's Vulture, with the DB-603 more akin to the Griffon (or R), though Development priority at Rolls Royce proceeded a fair bit differently.
> 
> I do wonder if a V-16 arrangement would have been any easier to work with, more a compromise between larger displacement V-12s and more complex multi-bank configurations. (plus should have lower frontal area than similar displacement V-12s, X-24s, or H-24s)
> An inverted V-16 using the DB-601's bore and stroke would have given slightly higher volume than the 603 and (in theory) significantly better volumetric efficiency at given compression/boost and fuel grade as well. (ideally, similar or better than what the DB-601 managed)



AS Wusak has said, the V-16 had some significant drawbacks to the basic layout. Most of the basic drawbacks were known as engine designers had at least doodled various layouts for years. The X-24s offered a shorter crankshaft and crankcase than the V-16. You can build decent V-16 engines, the trouble is that the way to avoid some of the problems with the long crankshaft (like torsional vibration) is to use both a heavier crankshaft in proportion to length and a heavier crankcase. 

AS for the comparison of the DB 603 and Griffon, the relationship to the smaller engines is there but the size comparison is not. The Griffon being much closer in size to the DB 605. The DB 603 was close in displacement (cylinder size) to the Russian AM-35/38 series of engines. 

Some engine designers obsessed a bit too much about frontal area. A seated pilot, even in the position of having the legs go almost straight out in front has a bigger "frontal" area than many (most) V-12 engines (not including radiator). On a twin engine bomber you have the frontal area of the fuselage being much larger than all but the biggest engines even on a small bomber. Obviously there is a big difference between a 5-6sq ft V-12 and a 16sq ft radial but the difference between a 5-6 sq ft V-16 and a 7-8sq ft V-12 isn't really going to be that great once you add in everything else.


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## Koopernic (May 29, 2015)

Shortround6 said:


> A lot depends on timing. The small cylinder but many cylindered engine has several advantages over a large cylinder engine.
> 1. The small cylinders offer better cooling. Both due to a higher cylinder wall to volume ratio and and a shorter path for the heat to travel from center of piston to cylinder walls. This allows for higher compression or higher boost than the big cylinder engine can use.
> 2. The smaller reciprocating parts allow for higher rpm. The DB 604 could turn about 18% more rpm than the DB 603.
> 3. The smaller cylinders _should_ show higher volumetric efficiency than large ones.
> ...



I don't really accept all of those arguments as having a significant effect. I think the main issue with big spark ignition cylinders was the propagation velocity of the flame front "deflagration" i.e. sustaining a stable burn that completes in time. One thing that you've listed as an advantage is better cooling is also a disadvantage, you don't want to be loosing heat from an engine, you want to retain it but cool the engine parts.


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## EKB (May 29, 2015)

Shortround6 said:


> Some engine designers obsessed a bit too much about frontal area.




Official flight test data of the Spitfire and Typhoon would seem to agree with that view. 

For example, Typhoon Ib R7700 (8 Nov 1942) and Spitfire IX JL165 (1 Feb 1944). The Napier Sabre and Merlin 66 engines were both supercharged to approximately 2000 bhp for the speed checks. Despite that the Typhoon was a much larger aircraft with its so-called "thick wings", there was hardly any difference from the Spitfire in level speed, at all heights up to 24,000 feet.

The British test pilots were either unable or unwilling to run the Sabre engine at full power during the trials of Typhoon R7700. Napiers advertised 2200 bhp on +9 lbs. Boost, but the A&AEE trials set limits of +7 lbs. Boost for level speed and +6 lbs. Boost for climbs.


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## Shortround6 (May 29, 2015)

The fuel/air mixture burned a pretty constant rate. Most designers wanted the combustion to be pretty much over with by the time the the piston was about 20 degrees past top dead center. Even with dual ignition this tended to put limits on both the cylinder bore and the stroke. You could use really big cylinders, you just couldn't run them very fast. Most aircraft engines used fixed ignition timing or at most a retard timing setting/device for starting or idle. 

Retaining heat in an engine is great for class room theory on efficiency. In the real world of 1930s and 40s the two main problems to getting (and surviving) aircraft engine power were heat and not breaking parts. 

Efficiency and max power sometimes need opposite features. The air cooled engines progress in power per liter or power per cylinder of like class engines follows the ability to put sq in of cooling fins on the cylinder. the more sq in of cooling fin surface the more power they could get from the cylinder. The liquid cooled engine didn't follow quite the same chart (and Wright published charts showing power development over the years in relation to cylinder fin area) but youhave the same problem. With any given fuel (87 octane or 100/130) you can only use so much compression and boost _and intake temperature._ raise the intake temperature 100 degrees and peak temperature in the cylinder goes up 100 degrees and the exhaust temperature goes up the same 100 degrees. Now our engine designer can try to use extra cooling of the cylinder ( and I include the cylinder head here) to lower the temperature a bit so he can use either a bit more boost or compression. the center of the piston was often a weak spot (not just on the DB 605 engine) so distances and "paths" of heat dissipation for the piston were often of concern. Piston either gets rid of heat to the cylinder walls or to oil on the bottom of the piston, either splashed or sprayed. 
The Bristol Hercules was another exercise in cooling, it not only went through something like 5 or more cylinder head designs (and a Hercules cylinder head did nothing except seal the top of the cylinder, hold the spark plugs, and provide cooling surface.) and in the post war versions was made of copper alloy instead of aluminium for even more heat transfer. You can worry about heat retention and efficiency of the engine after you stop melting holes in the tops of the pistons or cooking exhaust valves (R-3350s) or suffering other catastrophic failures. 

As for volumetric efficiency, there must be something to it. Practically every form of car or motorcycle racing has progressed to more and more cylinders for a given displacement unless the rules prohibit it. And in some cases 2 cylinder engines are given a displacement advantage against 4 cylinder engines to try to even things out.


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## tomo pauk (May 29, 2015)

EKB said:


> Official flight test data of the Spitfire and Typhoon would seem to agree with that view.
> 
> For example, Typhoon Ib R7700 (8 Nov 1942) and Spitfire IX JL165 (1 Feb 1944). The Napier Sabre and Merlin 66 engines were both supercharged to approximately 2000 bhp for the speed checks. Despite that the Typhoon was a much larger aircraft with its so-called "thick wings", there was hardly any difference from the Spitfire in level speed, at all heights up to 24,000 feet.
> 
> The British test pilots were either unable or unwilling to run the Sabre engine at full power during the trials of Typhoon R7700. Napiers advertised 2200 bhp on +9 lbs. Boost, but the A&AEE trials set limits of +7 lbs. Boost for level speed and +6 lbs. Boost for climbs.



Maybe this is where the small details kick in. Like the Typhoon having fully-enclosed main undercarriage and a retractable tailwheel, or, one radiator's group vs. two groups? Also, the test of the Typhoon IB R.8762 was said to be using new engine limits of 3700 rpm and +9 psi boost, old limits being same 3700 rpm but on +7 psi - that would be 1900 HP at SL with plenty of ram? 
The thicker wing should be having more problems where it would be closer to the critical Mach number - and that's felt more as the aircraft is higher, eg. like the Bearcat with thick wings having no problem at 5000 ft vs. aircraft with nominally more streamlined wings (P-51, Tempest)?


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## tomo pauk (May 29, 2015)

> dedalos said:
> 
> 
> > I am not sure. All series 5 fighters appear to be much cleaner than the Bf 109 and with more advanced wing profiles. The inferior speed of the tests could be result of derated italian DB 605s plus inferior propellers.
> ...


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## dedalos (May 29, 2015)

tomo pauk said:


> > I'm not sure that Italian Series 5 fighters were used any of the advanced wing profiles - the profiles used were pretty much the same as what was used on the MC.200, Re.2000 or G.50. The Bf 109G-6 was good for 620 km/h with gondola cannons and de-rated engine, or same as the G.55 with same firepower and same engine setting. Granted, the G.55 and Re.2005 should be more pleasant to fly since they were with bigger wing.
> > On the other hand, the ~385 mph of speed is still ~20 mph under the Fw-190A-4 or Spitfire VIII/IX of 1943. We want a 385 mph fighter with Db 605 and serious firepower? Produce the Fw 190 with DB 605.
> >
> >
> ...


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## Juha (May 29, 2015)

EKB said:


> Official flight test data of the Spitfire and Typhoon would seem to agree with that view.
> 
> For example, Typhoon Ib R7700 (8 Nov 1942) and Spitfire IX JL165 (1 Feb 1944). The Napier Sabre and Merlin 66 engines were both supercharged to approximately 2000 bhp for the speed checks. Despite that the Typhoon was a much larger aircraft with its so-called "thick wings", there was hardly any difference from the Spitfire in level speed, at all heights up to 24,000 feet.
> 
> The British test pilots were either unable or unwilling to run the Sabre engine at full power during the trials of Typhoon R7700. Napiers advertised 2200 bhp on +9 lbs. Boost, but the A&AEE trials set limits of +7 lbs. Boost for level speed and +6 lbs. Boost for climbs.



IMHO it is more on the intercooler radiator, see Spit XII (Griffon II 1760 hp at 1,000 ft and 372 mph at 5,500 ft) vs Typhoon Ib (Sabre II 2,180 hp 3,700 rpm and +9lb at sl and 374 mph at 5,500 ft). But radiators and the windscreen were the weak spots of the later part of the war Spits' aerodynamics together with the only partially covered undercarriage wheels.


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## kool kitty89 (May 29, 2015)

wuzak said:


> The DB 609 was essentially a V-16 version of the DB 603. It had similar power to the DB 604, but using larger capacity (62l vs 46l) and heavier weight.
> 
> V-16s will be longer than an equivalent V-12. The length of the crankshaft and camshafts potentially cause problems. That's why the Chrysler IV-2220 used a central gear drive, essentially making the engine two V8s.
> 
> ...


A V-16 using the 603's cylinders mitigates all of the advantages and compromises that the suggested DB-601 (or 605) derived V-16 would have. Size, weight, displacement, piston size, piston speed at given RPM, better piston cooling, higher practical RPM, etc. Plus, potentially at least some parts commonality and more directly shared development resources with the DB-601/605.

Though I suppose the same could be argued for Jumo 211/213 derived V-16 development over the Jumo 222. Then again, an X-24 derived from the Jumo 210 may have been more practical than the 222 as well.



Shortround6 said:


> Some engine designers obsessed a bit too much about frontal area. A seated pilot, even in the position of having the legs go almost straight out in front has a bigger "frontal" area than many (most) V-12 engines (not including radiator). On a twin engine bomber you have the frontal area of the fuselage being much larger than all but the biggest engines even on a small bomber. Obviously there is a big difference between a 5-6sq ft V-12 and a 16sq ft radial but the difference between a 5-6 sq ft V-16 and a 7-8sq ft V-12 isn't really going to be that great once you add in everything else.


True, though for multi-engine aircraft, the added drag is still notable given it's not hidden by the fuselage, and for either case the difference is more significant as engine sizes go up. (once you have the engine easily being the widest part of the aircraft -without extremely slim/tight fuselages like the Spitfire, 109, and He 100, it's a good deal more significant) The large frontal area is also one of the disadvantages of the Jumo 222. Same for radial engines in general, though the BMW 801 managed to minimize that rather well. 

For that matter the BMW 802 might have been more appealing if the stoke had been shortened somewhat to reduce diameter -losing some displacement/power may not have been a bad thing for development/time to service in that case either. (particularly if more compromises had been made on the supercharger and especially for use as a bomber engine)



Edit: I overlooked the X-16 arrangement. That should have been lighter and more compact than the XI-2220's arrangement while maintaining a shorter crankshaft and a single crankshaft rather than coupling at the gearbox. It'd be larger frontal area wise than a V-16 or X-24 of similar displacement, but should be mechanically simpler and easier to develop. (and again potentially share more in common with existing V-12s in development)





tomo pauk said:


> Maybe this is where the small details kick in. Like the Typhoon having fully-enclosed main undercarriage and a retractable tailwheel, or, one radiator's group vs. two groups? Also, the test of the Typhoon IB R.8762 was said to be using new engine limits of 3700 rpm and +9 psi boost, old limits being same 3700 rpm but on +7 psi - that would be 1900 HP at SL with plenty of ram?
> The thicker wing should be having more problems where it would be closer to the critical Mach number - and that's felt more as the aircraft is higher, eg. like the Bearcat with thick wings having no problem at 5000 ft vs. aircraft with nominally more streamlined wings (P-51, Tempest)?


Weather would be a big factor too, and smaller issues like whether the spitfire had full or clipped wings. Warmer air will further reduce mach related drag issues, while being less favorable in other respects.

It's still hard to believe that a 2000 HP spitfire wouldn't be faster than a 2000 HP Typhoon with that power maintained at given altitudes.
P-51 sure, even with considerably greater weight ... Tempest, maybe, but Typhoon? That'd be about as surprising as the Hurricane managing the same.


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## Juha (May 30, 2015)

In fact according a tabular form Spit LF. MK. IX +25 lb boost was 8 mph faster than Typhoon MK.IB (Sabre II +9 lb boost)from S.L. to 4,000 ft (the performance shown was from S.L. to 4,000 ft with 500 ft intervals).
See http://www.spitfireperformance.com/merlin66_18_25.jpg


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## tomo pauk (May 30, 2015)

> dedalos said:
> 
> 
> > tomo pauk said:
> ...


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## dedalos (May 30, 2015)

tomo pauk said:


> > dedalos said:
> >
> >
> > > The speed figures I've quoted for the Bf 109 are also for a restricted engine (1300 PS for take off). Any good source to back up the claim that G.55 have had inferior prop?
> > ...


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## kool kitty89 (May 30, 2015)

tomo pauk said:


> Exchange from BMW 801 to DB 605 means plenty of weight and drag is lost. The BMW 801D was above 1000 kg without oil system, pumps generators, mounts and cowling; whole powerplant was heavier than 1600 kg.


I was also suggesting said developments start back with the 601 in parallel with the original 190 prototypes (possibly as a superior alternative to the He 100 -and more versatile total replacement for the 109), so more potential divergence in structural strength/weight requirements for a totally lighter aircraft. (possibly also being better suited to the original small wing, though the larger area/lower wing loading and easier handling of the full sized wing might be preferable)

The 190 airframe would probably be easier to adapt to the Jumo 211 if the need/demand arose as well. (certainly easier than the He 100, possibly easier than the 109) And that option becomes more interesting once the 211F appears. (stronger crankshaft, higher rpm, pressurized cooling, more efficient supercharger, and potential further power boost for low-altitude optimized engines for ground attack and low-alt fighter work more needed on the eastern front) Perhaps more akin to an overboosted merlin powered P-40 in power/weight and overall size. (or maybe more like a P-40E/K using overboost/WEP down low but also with a high gear setting closer matching the 9.6:1 supercharger -so ~1,570 hp at ~4000 ft and 1,480 hp at ~10,000 ft with RAM)


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## Denniss (May 31, 2015)

Didn't the italian DB-engined fighters use german props or at least licence-built german props, the same as used by Bf 109 with DB 601A/605A ?


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## SpicyJuan11 (May 31, 2015)

So what would it take to get the Me 209 to be a great successor to the 109 and still keep the same amount of hoped part commonality? Or would it have been better to go with the G.55/56? If so, why didn't they?


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## tomo pauk (May 31, 2015)

dedalos said:


> It DOES matter why the FW was 20 km/h faster against the 1300 ps series 5 fighters. In order to gain speed used a smaller wing which resulted in very High wing loading which is BAD for rate of climb and manouverability. Also required the precious for germany C3 fuel. By the way the 801was more fuel hungry than the 605.



"There ain't such thing as a free lunch" applies as ever, along with 'every device is a compromise'. The strong points of the wing were excellent roll rate, plenty of internal space and (reasonably) low drag for good turn of speed. Stick a bigger wing and there is a gain in maneuverability and turn rate; shortcomings are decrease of roll rate (that is also a part of overall maneuverability), decrease of G limit and a small loss of speed. We can note that early Fw 190 was able to handily outclimb the lighter Spitfire V, as well as the USN Corsair and Hellcat, while the high roll rate was rated high in Allied reports about the Fw 190, whether from combat or from testing.
If we're worried about the prodigious rate of C3 consumption - stick the DB 605A on the Fw 190. 




> A G55 with 1475 Ps and the AS engine would be practically as fast as the 190A8 below 6000m and faster above that altitude, not to mention far superior handling. If we add c3 fuel or MW50 would be faster at all altitudes. Also would have a marginal power to weight advantage



It would be certainly a far better performer than the 190A-8. 
But there are flaws in your comparison - the Fw 190 was giving in winter of 1941/42 what the 'G.55AS' would be giving in Spring of 1944; everybody important was a better performer than the 190A-8, too. 


> You are right that Lw had from 1941/42 an 650KM/h fighter with 4 cannons. Yes, but that fighter was a dog above 6500m from the beginning. *And with little space for improvements without major redesign.* In order to reach 685 km/h it required an inline engine much heavier and powerful than the db 605, and despite sacrifising 2 cannons it still had an wing loading of over 230kgr/m2. I estimate that the G55 could reach that kind of speed on DB605D with a wing loading in the area of 185kgr/m2. Plus it carried 35 lt more fuel and a more economical engine. And bigger wings for additional tanks.




The bolded part would be expected from some LW-basher, and it is wide from the mark. Fw 190 possessed THE fighter airframe of ww2 (for land-based fighters), and was seldom equaled, let alone surpassed by another piston-engined airframes. 
Neither RAF, nor USAF, nor VVS were of opinion that Fw 190 was a dog above 6500 m, at least not prior mid 1943.
Why would you give the DB 605D for the G.55, and not to the Fw 190?? The engine of late 1944 (DB 605D) is not available in late 1943 (Jumo 213A, DB 603A); that LW failed to have Fw 190C/D in winter of 1943/44 is the fault of the RLM/LW themselves, not the incapability of Jumo or Fw. The G.56 was stated as 685 km/h fast, BTW.
Again - we're worried about high wing loading? Stick the DB 605A/AS/D on the Fw 190. 
As for the fuel - there is enough of space between the wing spars of the Fw 190, the late Doras were to have 4 fuel tanks installed there as Rustsatze. Plus, the drop tank facility - we have it on the Fw 190 (up to 3 tanks), the G.55 will need a modification in order to have them.


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## The Basket (May 31, 2015)

The Italian fighters didn't have anything better than the 109, maybe they were better aircraft but to cancel the 109 for a marginal replacement is hardly clever.
He 100d. Now that is another ballgame.
I see no problem with advancing Me 209 and trying to build a better fighter. If it doesn't work then that's called engineering.

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## Shortround6 (May 31, 2015)

The Basket said:


> He 100d. Now that is another ballgame..



Yep, a total loser. There was nothing wrong with the He 100 that throwing the whole thing out and starting over wouldn't have fixed. 
It offered very good speed on the engine power available but after that things go to pot in a hurry. None of them were ever fitted with armor or self sealing fuel tanks, it had a very large, cumbersome and vulnerable cooling system, it had limited space for armament _as built_. Now, most if not all things could be fixed but then you wind up with a plane so far from the original there is no point in trying to estimate performance based on the He 100 numbers.

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## GrauGeist (May 31, 2015)

Shortround6 said:


> Yep, a total loser. There was nothing wrong with the He 100 that throwing the whole thing out and starting over wouldn't have fixed.
> It offered very good speed on the engine power available but after that things go to pot in a hurry. None of them were ever fitted with armor or self sealing fuel tanks, it had a very large, cumbersome and vulnerable cooling system, it had limited space for armament _as built_. Now, most if not all things could be fixed but then you wind up with a plane so far from the original there is no point in trying to estimate performance based on the He 100 numbers.


The final emulation of the He100 was far from being a loser. It had the nessecary armor and conventional cooling system and was armed with two MG17 or two MG151/20 in the wings and the provision for a MG FF motorkannone.

While the combat dress did give it a performance penalty, it was still capable of max. speeds over 400 mph and a combat range twice that of the Bf109E.

What most likely killed the He100, was the fact that it relied on the DB601, which was in great demand for the Bf109 and Bf110 at the time because Daimler's difficulty in producing the 601 in sufficient numbers.

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## Shortround6 (May 31, 2015)

Any source for the MG 151/20mm guns _actually_ going in the wing roots? 

A pair of MG 17 machine guns is hardly first class armament. the MG FF may or may not have been fitted in actuality. I don't believe the ones the Russians got had it. ANd even if fitted there are no reports on how well it worked and the 109Es couldn't get the gun through the prop to work reliably. The Fs did but that is a bit after the He 100. There was talk and drawings/sketches of a wing with two MG 17s in each wing root but I am not sure if it was ever built or flown. It probably could have been built but we keep getting further from the condition/configuration the performance numbers are for. 


Some of them may have been fitted with armor, Is there any evidence they were fitted with self sealing tanks? 

The cooling system was never conventional. A retractable radiator was fitted but more a supplement to the cooling surfaces in the wings than a total replacement. The oil cooing system was never changed from the oil cooler being suspended in an alcohol tank behind the pilots seat with cooling surfaces for the alcohol being in the turtle deck, the horizontal stabilizers and the vertical fin. Quite a number of sq ft for bullets to hit and compromise the oil cooling system. Granted it is not an instant kill but what happens when a certain amount of alcohol leaks out?


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## EKB (Jun 1, 2015)

kool kitty89 said:


> Weather would be a big factor too, and smaller issues like whether the spitfire had full or clipped wings. Warmer air will further reduce mach related drag issues, while being less favorable in other respects.
> 
> It's still hard to believe that a 2000 HP spitfire wouldn't be faster than a 2000 HP Typhoon with that power maintained at given altitudes. P-51 sure, even with considerably greater weight ... Tempest, maybe, but Typhoon? That'd be about as surprising as the Hurricane managing the same.





Squadron Leader Neil of No. 41 Sqn noted that Spitfires built to Mk XII specs (1735 bhp with +12 lbs. Boost) were good for only 325 mph at sea level; or about 20 mph slower than the prototype.

_“ In the air, the Mk XII behaved much like any other Spitfire except that the engine was a good deal rougher than the Merlin — it grumbled rather than buzzed — and the beat of the big four-bladed airscrew was very pronounced. It was about 30mph faster low down than the Mk V for roughly the same engine settings, the nose wagging about like a terrier’s tail with any change of power. There being no provision for emergency boost — there was rather too much ‘urge’, anyway — 9lb was obtained with the throttle at the gate and 12lb beyond it, at which setting a genuine 325mph could be achieved at sea level.
As with earlier Spitfires, the aircraft’s maximum performance was obtained at around 18,000ft, where the second stage of the supercharger was engaged manually, using a lever on the left-hand side of the cockpit. In common with all two-speed superchargers, it came with a slightly worrying ‘clump’ although we seldom found ourselves using it as, more often than not, we were at 1,800ft rather than 18,000.”_

According to Jeffrey Quill, the Merlin 61 equipped Spitfire Mk IX did about 310 mph at sea level, which was rather disappointing performance in view of the high output engine (1570 bhp on +15 lbs. Boost). His favorite Spitfire was DP845 (the prototype Mk XII) which clocked in at 346 mph at sea level per the A&AEE.


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## Greyman (Jun 1, 2015)

EKB said:


> Squadron Leader Neil of No. 41 Sqn noted that Spitfires built to Mk XII specs (1735 bhp with +12 lbs. Boost) were good for only 325 mph at sea level; or about 20 mph slower than the prototype.



Going by the information at WWIIAircraftPerformance (Spitfire Mk XII Performance Testing) I wouldn't hold 325 mph as representative of what the Spitfire XII did on the deck.


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## Juha (Jun 1, 2015)

EKB said:


> Squadron Leader Neil of No. 41 Sqn noted that Spitfires built to Mk XII specs (1735 bhp with +12 lbs. Boost) were good for only 325 mph at sea level; or about 20 mph slower than the prototype.
> 
> _“ In the air, the Mk XII behaved much like any other Spitfire except that the engine was a good deal rougher than the Merlin — it grumbled rather than buzzed — and the beat of the big four-bladed airscrew was very pronounced. It was about 30mph faster low down than the Mk V for roughly the same engine settings, the nose wagging about like a terrier’s tail with any change of power. There being no provision for emergency boost — there was rather too much ‘urge’, anyway — 9lb was obtained with the throttle at the gate and 12lb beyond it, at which setting a genuine 325mph could be achieved at sea level.
> As with earlier Spitfires, the aircraft’s maximum performance was obtained at around 18,000ft, where the second stage of the supercharger was engaged manually, using a lever on the left-hand side of the cockpit. In common with all two-speed superchargers, it came with a slightly worrying ‘clump’ although we seldom found ourselves using it as, more often than not, we were at 1,800ft rather than 18,000.”_...



You can see a different info from the link I posted in my message #49, or if you want to rely on Neil, in the same book (From the Cockpit Spitfire) on the page 68 "In terms of performance, the Mk XII could outdistance a FW 190 - which it was obliged to do when operating in the reconnaissance role - and also the Typhoon..." Neil's personal a/c EN237 EB-V was according to him "one of those rare 'Friday afternoon' Spitfires - in short, a lemon!"


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## kool kitty89 (Jun 1, 2015)

Shortround6 said:


> Any source for the MG 151/20mm guns _actually_ going in the wing roots?
> 
> A pair of MG 17 machine guns is hardly first class armament. the MG FF may or may not have been fitted in actuality. I don't believe the ones the Russians got had it. ANd even if fitted there are no reports on how well it worked and the 109Es couldn't get the gun through the prop to work reliably. The Fs did but that is a bit after the He 100. There was talk and drawings/sketches of a wing with two MG 17s in each wing root but I am not sure if it was ever built or flown. It probably could have been built but we keep getting further from the condition/configuration the performance numbers are for.


The 'good' final (and only remotely service ready) iteration of the He 100's many different incarnations was the D-1, apparently very different from the D-0s sent to Russia and China (which still used the surface cooling system and was generally closer to the prototype racers). The D-1 is closer to what the thing should have started off with ... a corrected, streamlined/simplified followon to the He 112 with conventional retractable radiator (similar to the He 111, some He 112 variants, or single-seat Fw 187 prototypes) embedded in a slightly extended fuselage. All the aircraft of that limited production run were stationed as Heinkel factory defense and destroyed or otherwise lost during the war.

All that said, with the high wing loading, I really don't see much room for growth required for heavier engines and armaments without at very least extending the wingspan. I also don't see it as clearly superior to the contemporary Fw 190 prototypes (a comparison that would be much more clear had Tank also managed to secure DB-601s for testing on the initial lighter, smaller-wing aircraft). There's also less question of the Fw 190 airframe being adaptable to a variety of engines (including the Jumo 211 if need be) or its ability to carry a useful armament (even the small wing A-0s allowed for 6 Mg-17s).


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## SpicyJuan11 (Jun 1, 2015)

kool kitty89 said:


> The 'good' final (and only remotely service ready) iteration of the He 100's many different incarnations was the D-1, apparently very different from the D-0s sent to Russia and China (which still used the surface cooling system and was generally closer to the prototype racers). The D-1 is closer to what the thing should have started off with ... a corrected, streamlined/simplified followon to the He 112 with conventional retractable radiator (similar to the He 111, some He 112 variants, or single-seat Fw 187 prototypes) embedded in a slightly extended fuselage. All the aircraft of that limited production run were stationed as Heinkel factory defense and destroyed or otherwise lost during the war.
> 
> All that said, with the high wing loading, I really don't see much room for growth required for heavier engines and armaments without at very least extending the wingspan. I also don't see it as clearly superior to the contemporary Fw 190 prototypes (a comparison that would be much more clear had Tank also managed to secure DB-601s for testing on the initial lighter, smaller-wing aircraft). There's also less question of the Fw 190 airframe being adaptable to a variety of engines (including the Jumo 211 if need be) or its ability to carry a useful armament (even the small wing A-0s allowed for 6 Mg-17s).



Well yes, radical changes might have been necessary for further growth, but is it really that big of a deal considering the radical changes that the Bf 109 (F) and Fw 190 (D) went through? But any speculation on preformance (of the new variant), etc is really just that, speculation.

Also, I did some quick calculations on the wing loading between the Bf 109E and He 100D-1, and I found that the He 100 has a wind loading of 171.2kg/m while the Bf 109E has one of 159.5kg/m. Thoughts?

EDIT: It is worth noting that the Fw 190A had an even higher wing loading of 241.3kg/m(!).


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## EKB (Jun 1, 2015)

Juha said:


> You can see a different info from the link I posted in my message #49, or if you want to rely on Neil, in the same book (From the Cockpit Spitfire) on the page 68 "In terms of performance, the Mk XII could outdistance a FW 190 - which it was obliged to do when operating in the reconnaissance role - and also the Typhoon..." Neil's personal a/c EN237 EB-V was according to him "one of those rare 'Friday afternoon' Spitfires - in short, a lemon!"




True, but on the same page the author writes that his engine problem was cured with a new engine. The original motor was sent back to Rolls Royce. He never said that his assigned Spitfire was any slower or faster than others in his squadron.


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## blueskies (Jun 1, 2015)

kool kitty89 said:


> The 'good' final (and only remotely service ready) iteration of the He 100's many different incarnations was the D-1, apparently very different from the D-0s sent to Russia and China (which still used the surface cooling system and was generally closer to the prototype racers). The D-1 is closer to what the thing should have started off with ... a corrected, streamlined/simplified followon to the He 112 with conventional retractable radiator (similar to the He 111, some He 112 variants, or single-seat Fw 187 prototypes) embedded in a slightly extended fuselage. All the aircraft of that limited production run were stationed as Heinkel factory defense and destroyed or otherwise lost during the war.
> 
> All that said, with the high wing loading, I really don't see much room for growth required for heavier engines and armaments without at very least extending the wingspan. I also don't see it as clearly superior to the contemporary Fw 190 prototypes (a comparison that would be much more clear had Tank also managed to secure DB-601s for testing on the initial lighter, smaller-wing aircraft). There's also less question of the Fw 190 airframe being adaptable to a variety of engines (including the Jumo 211 if need be) or its ability to carry a useful armament (even the small wing A-0s allowed for 6 Mg-17s).



All of the he-100s produced had surface evaporation cooling. The retractable radiator on the D-1 subtype were to fix the problems with overheating during taxi and climb.

A proposed production version would have had a much larger belly radiator and no surface cooling. You can find a picture of this online.

There was also a plan to extend the wings by something like 1.2m. No drawings have been found of for this as of yet.

What ultimately killed the He-100 was that its performance with guns and armor wasn't much beyond the 109. Extend the wings and using a fully conventional cooling system would probably have brought performance close to parity.

Add to it that the trend then is towards larger fighters that can mount heavier armament and the 100 doesn't appear to offer much over the 109. Same thing happened with the first 209 project, which had some work carry over to the much larger and advanced 309.


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## SpicyJuan11 (Jun 1, 2015)

blueskies said:


> All of the he-100s produced had surface evaporation cooling. The retractable radiator on the D-1 subtype were to fix the problems with overheating during taxi and climb.
> 
> A proposed production version would have had a much larger belly radiator and no surface cooling. You can find a picture of this online.
> 
> ...



The initial (albeit extremely short) production version of the He-100 (the D-1) *did not* have surface cooling and also had armor. The performance was brought down a tad, but not nearly as much as you suggest.


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## tomo pauk (Jun 1, 2015)

If there was no surface cooling, where was the radiator?



blueskies said:


> ...
> 
> Add to it that the trend then is towards larger fighters that can mount heavier armament and the 100 doesn't appear to offer much over the 109. Same thing happened with the first 209 project, which had some work carry over to the much larger and advanced 309.



Good post. Just a nitpick - the Me 309 was barely bigger than the Bf 109, at least when we compare wing areas.


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## SpicyJuan11 (Jun 1, 2015)

tomo pauk said:


> If there was no surface cooling, where was the radiator?



The retractable radiator was underneath the cockpit.


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## The Basket (Jun 1, 2015)

It is difficult to discuss He100D as its all theory and rumour.
However...in comparison to the Italians...it was providing 400mph in 1940 while the Veltro was providing 400mph in 1944.
HAD the He100 been developed it may have been a better 109 replacement than a Serie 5


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## blueskies (Jun 1, 2015)

tomo pauk said:


> If there was no surface cooling, where was the radiator?
> 
> 
> 
> Good post. Just a nitpick - the Me 309 was barely bigger than the Bf 109, at least when we compare wing areas.



Yes, very true. Willy seemed to go the way of higher wing loading a bit too agressivly in his post 109 fighters. The first 209 was a victim of this, and his desire to keep the vert/hot stabilizer very small.



SpicyJuan11 said:


> The retractable radiator was underneath the cockpit.



Which, as per Erwin Hood, was used to suppliment the surface cooling. If you just look at the size of it you can tell that it is much too small to cool the DB engine by itself. It was also intended to be retracted when in suitably fast flight.


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## dedalos (Jun 1, 2015)

tomo pauk said:


> "There ain't such thing as a free lunch" applies as ever, along with 'every device is a compromise'. The strong points of the wing were excellent roll rate, plenty of internal space and (reasonably) low drag for good turn of speed. Stick a bigger wing and there is a gain in maneuverability and turn rate; shortcomings are decrease of roll rate (that is also a part of overall maneuverability), decrease of G limit and a small loss of speed. We can note that early Fw 190 was able to handily outclimb the lighter Spitfire V, as well as the USN Corsair and Hellcat, while the high roll rate was rated high in Allied reports about the Fw 190, whether from combat or from testing.
> If we're worried about the prodigious rate of C3 consumption - stick the DB 605A on the Fw 190.
> 
> *Eveything is a compromise. But we can look for the best combination of speed, turn,roll,diving,climbing,range, firepower, handling,potentional of development.In my opinion the italian fighters offered a better package than both the main german fighters *
> ...


.


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## Elmas (Jun 1, 2015)

The Basket said:


> ...........
> However...in comparison to the Italians...it was providing 400mph in 1940 while the Veltro was providing 400mph in 1944.
> ................



MC 205 Veltro first flight was April 19th 1942, and entered operative service in February 1943.

There was no problem attaching auxiliary tanks under the belly of the G 55....








tomo pauk said:


> ...............
> I'm not sure that Italian Series 5 fighters were used any of the advanced wing profiles - the profiles used were pretty much the same as what was used on the MC.200, Re.2000 or G.50.



The prototype of MC 200, as all the early monoplanes as the G50, had some problem of stability, so the the wing profiles were changed and wash out added. While the MC 200 wing was mantained both in MC202 and 205, both G55 and Re 2005 had different profiles than their predecessors.


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## SpicyJuan11 (Jun 1, 2015)

blueskies said:


> Which, as per Erwin Hood, was used to suppliment the surface cooling. If you just look at the size of it you can tell that it is much too small to cool the DB engine by itself. It was also intended to be retracted when in suitably fast flight.



Not for the D-1 version. The entire surface cooling system was abandoned and the retractable radiator was enlarged.


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## blueskies (Jun 1, 2015)

tomo pauk said:


> If there was no surface cooling, where was the radiator?
> 
> 
> 
> Good post. Just a nitpick - the Me 309 was barely bigger than the Bf 109, at least when we compare wing areas.





SpicyJuan11 said:


> The retractable radiator was underneath the cockpit.





SpicyJuan11 said:


> Not for the D-1 version. The entire surface cooling system was abandoned and the retractable radiator was enlarged.



Yes it was present in the so called D-1 series.

This is one of many things Erwin Hood states in his book on the He-100. As his book is quite well researched, and the definitive source on the He-100 as it stands, I'll take his word and sources over the many works that simply repeat what other books have written.


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## Shortround6 (Jun 1, 2015)

You have two cooling systems. The water and or glycol system and the oil system. We can argue back and forth on the retractable radiator being a stand alone or a supplement depending on whose source you have the most faith in but the oil system remained a surface cooled system with alcohol as the working fluid. 
There may be armour behind the pilot. Any bullet proof glass in front? 

You also have large flat fuel tanks in the wing.


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## dedalos (Jun 1, 2015)

Elmas said:


> MC 205 Veltro first flight was April 19th 1942, and entered operative service in February 1943.
> 
> There was no problem attaching auxiliary tanks under the belly of the G 55....
> 
> ...


.


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## SpicyJuan11 (Jun 1, 2015)

blueskies said:


> Yes it was present in the so called D-1 series.
> 
> This is one of many things Erwin Hood states in his book on the He-100. As his book is quite well researched, and the definitive source on the He-100 as it stands, I'll take his word and sources over the many works that simply repeat what other books have written.



I ordered the book today, I'll take a look, but then again much of the information (including blueprints) of the He 100 was lost, so I believe it is important to keep an open mind on such a little known subject.



Shortround6 said:


> You have two cooling systems. The water and or glycol system and the oil system. We can argue back and forth on the retractable radiator being a stand alone or a supplement depending on whose source you have the most faith in but the oil system remained a surface cooled system with alcohol as the working fluid.
> There may be armour behind the pilot. *Any bullet proof glass in front?*
> 
> You also have large flat fuel tanks in the wing.



There may be, but in any case, it's hard to see the LW accepting any that don't.


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## Shortround6 (Jun 1, 2015)

Some G 55s are said to be capable of carrying a pair of 160kg bombs under the wings. With suitable piping and pumps it would seem that 30imp gallon tanks would not be big problem. Post war versions (G 59s) definitely carried drop tanks ( they also used Merlin engines) 0f 125 liters (27.5 Imp gallons).


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## Shortround6 (Jun 1, 2015)

SpicyJuan11 said:


> There may be, but in any case, it's hard to see the LW accepting any that don't.


 At the time the He 100s were built the 109s were not being fitted with the armor, bullet proof glass and self sealing tanks they would have later in the BoB. It is hard to believe the HE 100s were fitted all three in 1939 when the 109s going into combat in Poland didn't have all three. 

Performance of a "service" He 100D (or whatever) becomes increasing conjecture as by the time of the BoB such features were being considered essential.


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## Juha (Jun 1, 2015)

EKB said:


> True, but on the same page the author writes that his engine problem was cured with a new engine. The original motor was sent back to Rolls Royce. He never said that his assigned Spitfire was any slower or faster than others in his squadron.



Yes but the engine was changed only after 3 months of efforts to get the original to work properly. And the a/c also had a drop tank jettisoning promlem which was never corrected. According to Neil on 2/3 of his cross Channel sorties EN237 drop tank didn't discard normally, it inpaled itself on the lugs, either sticking there and greatly reducing a/c's performance or whipping off sometimes later. But my main point was that according to Neil Mk XII was faster than either Typhoon IB or FW 190.


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## tomo pauk (Jun 1, 2015)

Elmas said:


> ...
> There was no problem attaching auxiliary tanks under the belly of the G 55....



That was the G.55S (S = silurante, or, very roughly, a 'torpedo fighter'). What was the cost in drag with two separated radiators, ease of modification? FWIW I like the idea 



> The prototype of MC 200, as all the early monoplanes as the G50, had some problem of stability, so the the wing profiles were changed and wash out added. While the MC 200 wing was mantained both in MC202 and 205, both G55 and Re 2005 had different profiles than their predecessors.



What type and thickness were the wing profiles of the G.55 and Re.2005?



Shortround6 said:


> ...
> You also have large flat fuel tanks in the wing.



That were not of self sealing variety?


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## SpicyJuan11 (Jun 1, 2015)

Shortround6 said:


> At the time the He 100s were built the 109s were not being fitted with the armor, bullet proof glass and self sealing tanks they would have later in the BoB. It is hard to believe the HE 100s were fitted all three in 1939 when the 109s going into combat in Poland didn't have all three.



I'll let you know when I get the book.


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## SpicyJuan11 (Jun 1, 2015)

tomo pauk said:


> That were not of self sealing variety?



It's pure speculation whether the He-100 had or did not have self-sealing fuel tanks unless Short would like to provide a source. I'll look for it in the book that I'm getting.


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## kool kitty89 (Jun 1, 2015)

SpicyJuan11 said:


> Well yes, radical changes might have been necessary for further growth, but is it really that big of a deal considering the radical changes that the Bf 109 (F) and Fw 190 (D) went through? But any speculation on preformance (of the new variant), etc is really just that, speculation.
> 
> Also, I did some quick calculations on the wing loading between the Bf 109E and He 100D-1, and I found that the He 100 has a wind loading of 171.2kg/m while the Bf 109E has one of 159.5kg/m. Thoughts?


Indeed, and with the number of changes going to the 109F variant and the (supposed) low parts count and mass production optimization of the He 100, switching over production rather than retooling for the 109F may have made a good deal of sense.

Keeping the 109E in production in the interim also would make sense, though so would have been producing more 109T-2s for applications where the longer span/area would be useful. (shorter take-off/landing, better handling with a bomb or drop tank, better turn rate, better lift/drag ratio -longer range albeit at slower optimal cruise speed- and higher service ceiling)



> EDIT: It is worth noting that the Fw 190A had an even higher wing loading of 241.3kg/m(!).


Also remember that the 190A greatly increased in weight from the A-1 to A-8, and a DB-601 powered version should have been significantly lighter. (enough that it may have had similar wing loading on the original small wing but certainly lower on the large one -and with a high lift airfoil at that, it very well may have out-turned the spitfire and maybe even hurricane while still being faster)

The 190 and He 100 both have better cockpit views and wider track landing gear than the 109, and while the He 100 has no service record to compare accident rates, the 190 was noted for being easier to take-off and land as well as easier to fly in general. (a lighter plane with lower wing loading and lower engine torque, lower stall speed, and more reliable power plant than the 801 initially was, while retaining or expanding on all the handling advantages the 190 offered)




blueskies said:


> All of the he-100s produced had surface evaporation cooling. The retractable radiator on the D-1 subtype were to fix the problems with overheating during taxi and climb.
> 
> A proposed production version would have had a much larger belly radiator and no surface cooling. You can find a picture of this online.





SpicyJuan11 said:


> The initial (albeit extremely short) production version of the He-100 (the D-1) *did not* have surface cooling and also had armor. The performance was brought down a tad, but not nearly as much as you suggest.


Indeed, from the limited information I've seen, the claims are that the pre-production He 100D-0 used surface cooling with a small, supplemental retractable radiator beneath the cockpit. 

The D-1 production aircraft supposedly equipped armor, were armed (and employed as factory defense), along with a deepened rear fuselage housing an expanded belly radiator and elliminating the surface cooling.

One part of the confusion may be that evaporative cooling was still used, but I believe this was true of all German water cooled engines that featured pressurized cooling systems. The coolant was allowed to (partially) boil in the cooling jacket and better transfer heat due to phase transition and particularly avoid hot spots, and featuring a centrifugal steam separator with the radiator being used to both cool the hot liquid and condense the limited amount of steam before returning it to the header tank. Evaporative cooling ended up being quite practical, especially with glycol or similar coolants in short supply (mainly used only as antifreeze in german engines), but it was surface cooling that went nowhere. (being extremely vulnerable, unreliable, and prone to overheating/warping aircraft skin -the same would apply to surface cooling omitting an evaporation/condensation component and simply piping hot coolant along the aircraft wing/fusalage surfaces -which the prototype and D-0 He 100s also did for both oil and coolant)

The sole prototype Fw 187 to be powered by DB 601 engines (not DB 600), I believe the V5, was fitted with similar engines with a pressurized cooling system and retractable radiators and is often confused with surface cooling (which I believe the DB 600 example did use) and may be a result of confusing terminology in use at the time with early/pre-production pressurized radiator DB 601s. (this was before the DB-601E entered production, or contemporary Jumo 211F -the 601A and 211A/B/C/D all using open-circuit cooling systems)

This also implies that the He 100 may not have been practical to adopt the DB-601A and possibly 601N (I'm not sure if that transitioned to pressurized cooling) without a significant redesign to the cooling system and higher capacity radiator and header tank than even the D-1 had adopted. The same would apply to the Jumo 211 short of the F model. (which would have still required some modifications to the mounts and cowling to accommodate). It would be the 601E with its pressurized cooling system or the earlier 601M (the version used on all He 100s actually flown) that would be needed.







dedalos said:


> _Fw 190 possessed THE fighter airframe of ww2 (for land-based fighters), and was seldom equaled, let alone surpassed by another piston-engined airframes._
> It was constructed vey strong, actually TOO strong. It was heavy. It was good for ground attacking, but all this weight was bad for the Air superiority role. It s not luck that the best Air superiority fighters of the was were NOT famous for their toughness(Spitfire,P51,KI84,La7


Take the Mustang off that list, it was about as overbuilt and correspondingly heavy for its size as the P-40 and P-39 (and pretty much all American fighters). It just had the advantage of exceptionally low drag for its weight and size.

Also remember that the 190A-8 and D were both much heavier than the earlier A models. Between the heavy engine, armor, and armament (and ammunition), the A-8 would be more akin to weighing the P-51D down with enough armor to protect it's large radiator area and carry a full complement of 4 Hispano cannons, maybe even adding the cowl mounted .50s.

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## SpicyJuan11 (Jun 1, 2015)

kool kitty89 said:


> Also remember that the 190A greatly increased in weight from the A-1 to A-8, and a DB-601 powered version should have been significantly lighter. (enough that it may have had similar wing loading on the original small wing but certainly lower on the large one -and with a high lift airfoil at that, it very well may have out-turned the spitfire and maybe even hurricane while still being faster)



Yes, I compared the A-8 version, but the A-1 had a wing loading of 206kg/m still higher than that of the He-100.


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## The Basket (Jun 1, 2015)

The Fw 190 was built because of the radial engine. It would have shared the same fate as the He100 if it took engines away from the Messerschmitt.
Even a poor performing He 100 dragged down with armour and cannon would still have been one of the fastest machines of its day and superior to the P-40 and 109E. The question...is whether in a 1944 timeframe would a 109 be better than a 100? A silly question to ask in 1940 but I suppose that is what its about.


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## Shortround6 (Jun 1, 2015)

I am not worried about the cannon's weight, I would be worried about it actually working in 1939 and 1940. If it doesn't (and the 109s engine cannon didn't work in those years) you are down to the two machineguns or if we are feeling charitable, four MG 17s in the wing roots. 
I would also be worried about the effect of self-sealing tanks. I have the book in question and it doesn't say one way or the other. However most if not all of the He 100s were completed in 1939 with the last ones finished in very early 1940.
Records are not good. Officially there were NO 100Ds. There were 5 pre series aircraft V1-4 and V8. There were 3 A-O aircraft or block I aircraft, V5, V6 and V7. The block II aircraft comprised the V9/A-04, the V-10/A-05 and the A-06 - A-014 but not all _may_ have been completed. The Block III aircraft were to be designated A-015 - A-025. Exact cut off of production is not given. either 24 or 25 airframes total were built. 6 went to Russia, 3 went to Japan one or two were tested to destruction in ground rigs, one crashed in Sept 1938 (V3) and the V8 went to the Deutsches Museum. 

According to the book there were no company records of B, C, or D versions or at least no surviving records. 

Detail design work on the 4 gun wing was halted very early during project (or at least by the time the first few planes had flown.


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## The Basket (Jun 1, 2015)

The He 113 had excellent performance 
Now there was a fighter.

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## GrauGeist (Jun 2, 2015)

The Basket said:


> The He 113 had excellent performance
> Now there was a fighter.


However, they were reportedly encountered and shot down even as late as 1943!

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## SpicyJuan11 (Jun 2, 2015)

Shortround6 said:


> I am not worried about the cannon's weight, I would be worried about it actually working in 1939 and 1940. If it doesn't (and the 109s engine cannon didn't work in those years) you are down to the two machineguns or if we are feeling charitable, four MG 17s in the wing roots.
> I would also be worried about the effect of self-sealing tanks. I have the book in question and it doesn't say one way or the other. However most if not all of the He 100s were completed in 1939 with the last ones finished in very early 1940.
> Records are not good. Officially there were NO 100Ds. There were 5 pre series aircraft V1-4 and V8. There were 3 A-O aircraft or block I aircraft, V5, V6 and V7. The block II aircraft comprised the V9/A-04, the V-10/A-05 and the A-06 - A-014 but not all _may_ have been completed. The Block III aircraft were to be designated A-015 - A-025. Exact cut off of production is not given. either 24 or 25 airframes total were built. 6 went to Russia, 3 went to Japan one or two were tested to destruction in ground rigs, one crashed in Sept 1938 (V3) and the V8 went to the Deutsches Museum.
> 
> ...



That's just arguing over semantics. Sure one can argue that there were no A,B,C,D's but really they are all equated to the prototypes anyways. Thanks for mentioning the self-sealing fuel tanks, I guess that detail was lost with the documents, but I also bought the Schiffer book as well and I'll see if it mentions it anywhere.



The Basket said:


> The He 113 had excellent performance
> Now there was a fighter.



Not sure if you're being facetious since the He 100 was originally supposed to be designated as the He 113 but was changed to He 100 because of the chance of "bad luck". Then when the He 100 was used for propaganda purposes where it was designated He 113 and 3 were reported downed during the BoB by British pilots


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## Edgar Brooks (Jun 2, 2015)

EKB said:


> Squadron Leader Neil of No. 41 Sqn noted that Spitfires built to Mk XII specs (1735 bhp with +12 lbs. Boost) were good for only 325 mph at sea level; .


If I might be permitted to make a slight correction, Neil said they got a "genuine" 325 mph, which doesn't have quite the same ring about it as "only," in fact one could be forgiven for thinking that he was actually quite pleased with it, especially as he later says, " In terms of performance, the Mk.XII could outdistance a FW190 - as it was obliged to do when operating in the reconnaissance role - and also the Typhoon. As regards in-fighting, there were few opportunities to test our Mk.XII's capabilities, although we were always confident we could outperform anything the opposition could put up, most encounters resolving themselves into high-speed chases or escapes,"


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## blueskies (Jun 2, 2015)

tomo pauk said:


> Indeed, from the limited information I've seen, the claims are that the pre-production He 100D-0 used surface cooling with a small, supplemental retractable radiator beneath the cockpit.
> 
> The D-1 production aircraft supposedly equipped armor, were armed (and employed as factory defense), along with a deepened rear fuselage housing an expanded belly radiator and elliminating the surface cooling.
> 
> One part of the confusion may be that evaporative cooling was still used, but I believe this was true of all German water cooled engines that featured pressurized cooling systems. The coolant was allowed to (partially) boil in the cooling jacket and better transfer heat due to phase transition and particularly avoid hot spots, and featuring a centrifugal steam separator with the radiator being used to both cool the hot liquid and condense the limited amount of steam before returning it to the header tank. Evaporative cooling ended up being quite practical, especially with glycol or similar coolants in short supply (mainly used only as antifreeze in german engines), but it was surface cooling that went nowhere. (being extremely vulnerable, unreliable, and prone to overheating/warping aircraft skin -the same would apply to surface cooling omitting an evaporation/condensation component and simply piping hot coolant along the aircraft wing/fusalage surfaces -which the prototype and D-0 He 100s also did for both oil and coolant)



The cooling system in the all built versions of the He-100 used evaporative, ie condensing steam in the wings, for cooling. The tiny retractable radiator was added between the wing header tank circuit, and offered negligible cooling when retracted.

We know that the last production block (D-1) used this system as photos of the engine bay exist that show several features related to the steam cooling system.

As for the deeper radiator on the D-1: I believe that you are getting confused with the proposed production/export model for Japan, which did do away with the complex cooling system and replaced it with a deeper radiator. A quick comparison of photos of the Soviet 100d with the d-1s will show their radiators to be the same.

Furthermore, at least one He-100 was flown with He-177 style radiators. Although this may have been as part of aerodynamic testing for that program.


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## tomo pauk (Jun 2, 2015)

Seems something is wrong with the quote


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## Elmas (Jun 2, 2015)

Shortround6 said:


> Some G 55s are said to be capable of carrying a pair of 160kg bombs under the wings. With suitable piping and pumps it would seem that 30imp gallon tanks would not be big problem. Post war versions (G 59s) definitely carried drop tanks ( they also used Merlin engines) 0f 125 liters (27.5 Imp gallons).


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## Elmas (Jun 2, 2015)

tomo pauk said:


> What type and thickness were the wing profiles of the G.55 and Re.2005?



Macchi MC.200 Saetta root NACA 23018 mod tip NACA 23009 mod
Macchi MC.201 NACA 23018 mod NACA 23009 mod
Macchi MC.202 Folgore NACA 23018 mod NACA 23009 mod
Macchi MC.205 Veltro NACA 23018 mod NACA 23009 mod

Fiat G.50 Freccia NACA ??15 NACA ??10
Fiat G.55 NACA 2415 NACA 2409
Fiat G.59 NACA 2415 NACA 2409

Of course you won’t count on the fact that we Italians can use a profile without eavily modify it, I hope.... but the most important feature to improve the stability that first monoplanes were lacking was adding the wash-out, that came out from some German papers arised in the second half of the thirties.

I wasn’t able to find the exact profile of Reggiane fighters: the factory was heavily bombed, and almost all the drawings were destroyed: almost of the knowledge about Re 2005, of wich the only original existing piece is a section of the fuselage, is from the memories of C.te De Prato, his test Pilot.








tomo pauk said:


> That was the G.55S (S = silurante, or, very roughly, a 'torpedo fighter'). What was the cost in drag with two separated radiators, ease of modification? FWIW I like the idea



To keep a long story short, Nazis wanted to stop the production of Fiat G55 and to transport the skilled manpower from Turin to Germany. Of course something had to be invented to avoid this so Fiat management and C.te Adriano Mantelli, one of the most skilled Pilots of ANR, did invent a thing that no german fighter of those times could do, carry a quite normal aeriel torpedo under the belly. A prototype was hurriedly produced and C.te Mantelly exibit himself in a complete aerobatics programme with the torpedo underneath, to convince the German Commission that G55 had a future....

We don't have to go far to find some nice photos:
http://www.ww2aircraft.net/forum/ai...hters-training-liaison-aircrafts-33172-2.html

The connections for tanks or bombs can be clearly seen:


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## SpicyJuan11 (Jun 2, 2015)

blueskies said:


> The cooling system in the all built versions of the He-100 used evaporative, ie condensing steam in the wings, for cooling. The tiny retractable radiator was added between the wing header tank circuit, and offered negligible cooling when retracted.
> 
> We know that the last production block (D-1) used this system as photos of the engine bay exist that show several features related to the steam cooling system.
> 
> ...



Honestly I wouldn't be surprised if you or the author got something wrong as I have found nothing to support that the Japanese bought D-1's (the version without surface cooling prevalent in all previous versions). 

Also, take a look at this:






Heinkel He 100 D-0











Heinkel He 113 (otherwise known as He 100 D-1)


The D-1's radiator looks clearly bigger to me.

Found this as well. I'm quite sure that this is the Japanese He 100 D-0 renamed AXHei


_View: https://www.youtube.com/watch?v=hPzw3LNPgpU_


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## blueskies (Jun 2, 2015)

SpicyJuan11 said:


> Honestly I wouldn't be surprised if you or the author got something wrong as I have found nothing to support that the Japanese bought D-1's (the version without surface cooling prevalent in all previous versions).



You misunderstood.

There was a variant of the He-100 with an enlarged radiator in a deepened fuselage intended for license production in Japan.

I meant that this might be where he is getting the idea that the "D-1" had no surface cooling. In reality the later production block aircraft possessed tweaked versions of the cooling system from the v series.

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## GrauGeist (Jun 2, 2015)

blueskies said:


> You misunderstood.
> 
> *There was a variant of the He-100 with an enlarged radiator in a deepened fuselage intended for license production in Japan.*
> 
> I meant that this might be where he is getting the idea that the "D-1" had no surface cooling. In reality the later production block aircraft possessed tweaked versions of the cooling system from the v series.


The 3 sold to Japan were the D-0, designated as the AXHei by the IJN/IJA and a factory was being constructed at Chiba to produce them. They were not intended as export, and had to receive permission from the RLM before sales to any country was considered. 

Seven of the prototypes were sold to Russia:
V1, V2, V4, V5, V6 and V7


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## SpicyJuan11 (Jun 2, 2015)

GrauGeist said:


> The 3 sold to Japan were the D-0, designated as the AXHei by the IJN/IJA and a factory was being constructed at Chiba to produce them. They were not intended as export, and had to receive permission from the RLM before sales to any country was considered.
> 
> Seven of the prototypes were sold to Russia:
> V1, V2, V4, V5, V6 and V7



What are you implying GrauGeist? That the D had a larger radiator?


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## Shortround6 (Jun 2, 2015)

I believe in the above drawing the items labeled 2 are fuel tanks, the items labeled 1 are part of the cooling system. Not sure on item 2. Areas on rear fuselage, fin and horizontal stabilizers are part of the oil cooling system.
Some of the late series aircraft got a fuel tank added behind the cockpit.
The issue with the wing fuel tanks and self sealing is the shape. Large area but flat tanks require a greater weight of self sealing material for their capacity that squaty fat tanks. And the loss of capacity is proportionally greater when the hight is fixed ( wing thickness).
The He 100 was a very nice example of streamlining and tight packaging but it's utility as a practical warplane may be subject to qestion, especially in 1940 when it was faced with doubtful armament in addition to the added operational/protective equipment needed. 
Had either the MG 131 or MG 151 been a lot further along in development the armament problem would not have been so bad.


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## Shortround6 (Jun 2, 2015)

Duplicate


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## SpicyJuan11 (Jun 2, 2015)

blueskies said:


> You misunderstood.
> 
> There was a variant of the He-100 with an enlarged radiator in a deepened fuselage intended for license production in Japan.
> 
> I meant that this might be where he is getting the idea that the "D-1" had no surface cooling. In reality the later production block aircraft possessed tweaked versions of the cooling system from the v series.



blueskies, that looks like a D-0 aircraft that was sent to Japan.


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## GrauGeist (Jun 2, 2015)

Dang...I know the forum's server has problems with popping up double posts...but there's a half hour between SR's...I think that might be a new forum record!


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## GrauGeist (Jun 2, 2015)

SpicyJuan11 said:


> What are you implying GrauGeist? That the D had a larger radiator?


If you examine the D-0/D-1 closely, you'll find that there is an opening below the spinner, in the "chin" area. In several factory photos, traces of oil can be seen coming from this area, especially after tests. Also, in comparing factory photos of earlier types to the D-1 types, there is a noticable increase in the radiator's size...particularly width-wise.

The frustrating thing about following the He100 project, is that virtually no factory documentation or work notes survive, so it requires a great deal of detective work to solve some of these mysteries.

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## blueskies (Jun 2, 2015)

GrauGeist said:


> If you examine the D-0/D-1 closely, you'll find that there is an opening below the spinner, in the "chin" area. In several factory photos, traces of oil can be seen coming from this area, especially after tests. Also, in comparing factory photos of earlier types to the D-1 types, there is a noticable increase in the radiator's size...particularly width-wise.
> 
> The frustrating thing about following the He100 project, is that virtually no factory documentation or work notes survive, so it requires a great deal of detective work to solve some of these mysteries.



That opening just below the spinner is to allow cool air into the engine compartment. It has nothing to do with the oil cooling system.

The 109e series had similar vents.


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## tomo pauk (Jun 2, 2015)

Elmas said:


> Macchi MC.200 Saetta root NACA 23018 mod tip NACA 23009 mod
> Macchi MC.201 NACA 23018 mod NACA 23009 mod
> Macchi MC.202 Folgore NACA 23018 mod NACA 23009 mod
> Macchi MC.205 Veltro NACA 23018 mod NACA 23009 mod
> ...



Thanks. Basically, the fighters used classic wing profiles, the NACA 24 serise should predate the 230 series?



> To keep a long story short, Nazis wanted to stop the production of Fiat G55 and to transport the skilled manpower from Turin to Germany. Of course something had to be invented to avoid this so Fiat management and C.te Adriano Mantelli, one of the most skilled Pilots of ANR, did invent a thing that no german fighter of those times could do, carry a quite normal aeriel torpedo under the belly. A prototype was hurriedly produced and C.te Mantelly exibit himself in a complete aerobatics programme with the torpedo underneath, to convince the German Commission that G55 had a future....



Fw 190 was also tested with a torpedo, the extended strut of the tailwheel being a less eye-pleasing thing than on the G.55S. (picture)



SpicyJuan11 said:


> Honestly I wouldn't be surprised if you or the author got something wrong as I have found nothing to support that the Japanese bought D-1's (the version without surface cooling prevalent in all previous versions).
> Also, take a look at this:
> ...
> The D-1's radiator looks clearly bigger to me.



The radiator on the He 100 on the 1st picture looks the same as the radiator on the fighter numbered '21' depicted on the picture at the bottom left.


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## GrauGeist (Jun 2, 2015)

blueskies said:


> That opening just below the spinner is to allow cool air into the engine compartment. It has nothing to do with the oil cooling system.
> 
> The 109e series had similar vents.


So did the earlier block of He100 airframes. But according to several authors, there is debate about this larger inlet on the D series and the fact that there isn't evidence of oil tracing on the earlier series.

And, this isn't a Messerschmitt...

Here is one factory photo that has been used in the possible oil cooler debate...there are a few others, but not of this quality.

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## tomo pauk (Jun 2, 2015)

The Bf 109E also have had the shallow inlet just under the spinner, plus of course the inlet for the oil cooler itself - picture.


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## kool kitty89 (Jun 2, 2015)

The Basket said:


> The Fw 190 was built because of the radial engine. It would have shared the same fate as the He100 if it took engines away from the Messerschmitt.
> Even a poor performing He 100 dragged down with armour and cannon would still have been one of the fastest machines of its day and superior to the P-40 and 109E. The question...is whether in a 1944 timeframe would a 109 be better than a 100? A silly question to ask in 1940 but I suppose that is what its about.


That's also part of my point: with proper strategic planning/logistics management, etc, Messerschmitt would NOT have gotten priority for engines like they historically did, and the Bf 109 should have been replaced by something better following the E/T models ... or at least they should have been trying very hard to stop production in favor of something more potent as both a defensive and offensive weapon. (if DB-601N/E/605 powered He 100 and Fw 190 derivatives proved genuinely worse than the existing 109F/G series -not just in speed/climb, but firepower, range, visibility, dive performance, and handling -on the ground and air- then they'd have been still stuck with the 109, but I see that as rather unlikely -there's the Fw 187 to consider as well, especially as a defensive weapon)

That said, with RLM policy as it was, using the Jumo 211 for testing on more fighters might have helped too. (particularly engineering a plane flexible enough to adapt to a variety of power plans and potentially directly switch between fairly similar engines on the production line -like say, designing the He 100 a bit less tightly and allowing it to accept either a Jumo 211 or DB 600, though the Fw 190 would probably be easier to adapt to such, perhaps somewhat like the differences between the Merlin and Allison powered P-40s) Though in heinkel's case, designing a fighter that expressly shared at least partial parts commonality with the nacelles and radiators designed for the DB-600/601 and 211 powered He 111 models would have been efficient/attractive in terms of mass production and maintenance.


And on the note of the Fw 187, here's some relevant photos of the retractable radiators used on the single-seat prototypes:
http://www.warbirdphotographs.com/LCBW6/FW187-V2-16f.jpg
http://www.airwar.ru/image/idop/fww2/fw187/fw187-5.jpg
http://www.airwar.ru/image/idop/fww2/fw187/fw187-6.jpg
http://aviarmor.net/aww2/_photo_aircraft/f_ger/fw187/fw187v1_1.jpg
http://aviarmor.net/aww2/_photo_aircraft/f_ger/fw187/fw187v1_2.jpg
(all rather like smaller versions of what the He 111 used)

And also the radiator from the DB-601 powered V5 prototype with radiator in fully retracted position on the ground:
http://s412.photobucket.com/user/ruspren/media/ruspren001/IMG_0695_zps8b3c015f.jpg.html

Those DB-601s apparently used a similar steam/evaporative pressurized cooling system as well, so not the standard DB-601A/N models used on contemporary 109Es. (also not like the surface cooling used on the earlier DB-600 powered Fw 187 prototype example)

Much of this was discussed at length here:
http://www.ww2aircraft.net/forum/aviation/fw-187-german-51-a-38757-20.html
(albeit with a fair amount of cross-talk and missed points along the way, the more recent post I made there attempted to summarize some of that information and address some of the confusion)





blueskies said:


> The cooling system in the all built versions of the He-100 used evaporative, ie condensing steam in the wings, for cooling. The tiny retractable radiator was added between the wing header tank circuit, and offered negligible cooling when retracted.
> 
> We know that the last production block (D-1) used this system as photos of the engine bay exist that show several features related to the steam cooling system.


This is all true except for the surface cooling aspect. All versions used pressurized steam cooling systems, but only some of them used surface cooling (both for condensing and -more so, I believe- simply cooling the hot, pressurized liquid coolant) as well as surface cooling for oil in the rear fuselage. (non-evaporative in this case)

Such a system can just as well apply for using a fixed, centralized radiator for cooling/condensing the water and oil before sending them back to their respective header tanks, and this is what the D-1 supposedly did (as well as the prototype modified to test this arrangement). It should also be fairly similar to the pressurized cooling systems used on the DB-601E and Jumo 211E (and later models) including use of a steam separator on all models. (I'll need to check again, but from what I recall, all those systems took advantage of limited boiling inside the cooling jacket, nucleating mostly around hot spots in the engine, and the water was then sent though a centrifugal steam separator, sending the liquid portion straight to the radiator -and/or surface cooling ducts- while allowing the limited amount of water vapor to condense before joining the rest of the liquid)




Shortround6 said:


> I believe in the above drawing the items labeled 2 are fuel tanks, the items labeled 1 are part of the cooling system. Not sure on item 2. Areas on rear fuselage, fin and horizontal stabilizers are part of the oil cooling system.
> Some of the late series aircraft got a fuel tank added behind the cockpit.


Indeed, and the portion labeled 3 may be the oil header tank or just an expanded portion of the oil cooling system with the rear fuselage being insufficient? (I recall that being mentioned as well)



> The issue with the wing fuel tanks and self sealing is the shape. Large area but flat tanks require a greater weight of self sealing material for their capacity that squaty fat tanks. And the loss of capacity is proportionally greater when the hight is fixed ( wing thickness).


Indeed, though allowing the areas relegated to surface cooling be filled with fuel tanks (as with the P-38's intercoolers) this difference could at least be partially offset, in spite of the difficulties of flat fuel tanks.

One thing I missed on previous discussions on the P-39's wing tanks was that the XP-39 had lacked any provision for guns in the wings and could thus rely on the outer wing panels for fuel where the production models carried the 4 M1919s and 1000 round capacity ammunition boxes. (the higher weight to volume ratio for the P-39's tanks compared to the P-40's would still be relevant, of course -flat tanks are heavier than tub tanks of the same volume) In fact, if the He 100 was anywhere near (or better than) the drag characteristics of the P-39, it would have been a winner, over the 109 at least. (powered by engines on the level of the 109F and G ... hell, even the contemporary Jumo 211 models would be better than what the engines the P-39 was getting throughout the war, same for the sluggish WEP ratings -at least compared to British practice)


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## kool kitty89 (Jun 2, 2015)

Shortround6 said:


> I am not worried about the cannon's weight, I would be worried about it actually working in 1939 and 1940. If it doesn't (and the 109s engine cannon didn't work in those years) you are down to the two machineguns or if we are feeling charitable, four MG 17s in the wing roots.
> I would also be worried about the effect of self-sealing tanks. I have the book in question and it doesn't say one way or the other. However most if not all of the He 100s were completed in 1939 with the last ones finished in very early 1940.


I don't think it would be a very good plane to target 1940 or in place of the 109E (or T if they'd made more of them) but as a compliment to the 190 and alternative to the 109F entering production at all.

The engine used in the He 100 might have allowed satisfactory use of the MG-FF or MG-FF/M where the 109 struggled with any nose gun. (the He 112 apparently managed better than the Jumo 210 powered 109 prototypes attempting MG-17 or MG-FF motor cannon)

1 MG-FF and 2 MG 17s would still be a bit weak compared to the 109E's armament, somewhat less so if the 100 round drum was used. But given the overall timing, I don't think the He 100 would have been ready for volume production early enough to supplant the 109E. (equipping 109Es with belly racks sooner would be more feasible and significant, as would adopting the 109T-2 for Jabo use with the longer span wing)






blueskies said:


> That opening just below the spinner is to allow cool air into the engine compartment. It has nothing to do with the oil cooling system.
> 
> The 109e series had similar vents.





tomo pauk said:


> The Bf 109E also have had the shallow inlet just under the spinner, plus of course the inlet for the oil cooler itself - picture.


Indeed, and any streaks on the cowling below the engine very well could have been oil as well, from the engine itself, and by no means evidence that the oil cooling system was near the nose.


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## GrauGeist (Jun 2, 2015)

Sure...Heinkel looked to Messerschmitt for his own designs so naturally they'd be identical, right?

The point that was being made but that speculation, was that the aircraft had been designed around the ill-fated evaporitive system. In an attempt to bring the Series II airframes up to a conventional standard, Heinkel's engineers were making the best use out of existing spaces.

I've had to do similar efforts when putting a different engine/trans setups into a vehicle it wasn't designed for, so I could accept that possability.

There is no conctrete proof that there was just as much as there's no concrete proof that there wasn't.

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## wuzak (Jun 2, 2015)

GrauGeist said:


> Sure...Heinkel looked to Messerschmitt for his own designs so naturally they'd be identical, right?



If you are talking of teh duct under the spinner, it may just be a requirement for the engine.


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## Shortround6 (Jun 2, 2015)

kool kitty89 said:


> One thing I missed on previous discussions on the P-39's wing tanks was that the XP-39 had lacked any provision for guns in the wings and could thus rely on the outer wing panels for fuel where the production models carried the 4 M1919s and 1000 round capacity ammunition boxes. (the higher weight to volume ratio for the P-39's tanks compared to the P-40's would still be relevant, of course -flat tanks are heavier than tub tanks of the same volume) In fact, if the He 100 was anywhere near (or better than) the drag characteristics of the P-39, it would have been a winner, over the 109 at least. (powered by engines on the level of the 109F and G ... hell, even the contemporary Jumo 211 models would be better than what the engines the P-39 was getting throughout the war, same for the sluggish WEP ratings -at least compared to British practice)



The XP-39 carried 200 gallons of fuel and the YP-39s and P-39C carried 170 gals. P-39D-M carried 120 gal. Now perhaps the early ones did run the fuel tanks out beyond the later ones and into what would become the wing machine gun area. On the other hand the early P-38s carried 400-410 gals in 4 tanks in in the wing roots. This decreased to 300 gallons with self sealing tanks fitted into the same spaces in the P-38s thick wing roots. A YP-38s unprotected tanks (and piping) weighed 121.4lbs. A P-38J with with 6 fuel tanks (a 55 gal tank in the each wing leading edge being added) and carrying 410 gallons had a fuel system that weighed 505.8lbs. 
P-40s went from a 171lb 3 tank system holding 180 gals(?) to a 233lb 3 tank system holding 160 gallons on the P-40B to a 425lb 3 tank system holding 148 gallons. The P-40Ls (and first Ns) had a two tank system holding 120 gallons that weighed 322lbs. A P-39 with 120 gals had a fuel system that went about 290lbs.


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## blueskies (Jun 4, 2015)

I'll just make some points here rather then quoting. It doesn't work properly on this phone browser.

Some He-100s were fitted with 601a series engines.

The D-1 and D-0 subtypes are misnomers. The proper name, per heinkel documents is A-0. This was a small run of mostly handbuilt machines in three production batches. Sometimes an earlier batch machine would be modified to later batch standards. This happened to 3 sold to the Soviet Union.

All the He-100s produced were equipped with the surface cooling in the wings as well as the oil cooling in the fuselage. This is most definitely true of the A-0 run (with on caveat) and is known from photos of the engine bay of A-0s as well as photos of A-0s showing heavy weathering on the paint in the exact places where the surface cooling is located.

Caveat from above: Heinkel documents indicate that 6 of the A-0 machines were planned to be set aside for wing radiator experiments. There are some heinkel drawings of this, and a photo of a He-100 with 177 style leading edge radiators.

Landing gear troubles plagued the He-100 throughout its life. It was a complicated mechanism that was redesigned at least once. Finally the gear was altered so that the legs were interchangeable between sides.

The vent on the underside of the spinner is not heinkel copying messerschmitt but arriving at a similar solution to the same problem. That vent went through a number of variations and modifications. Similar vents can be spotted on virtually every 601 engined plane I can think of.

If I remember right tsagi tested out a whole bunch of aircraft in its windtunnel and found the p-39 to be the lowest in c/d.


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## SpicyJuan11 (Jun 4, 2015)

blueskies said:


> I'll just make some points here rather then quoting. It doesn't work properly on this phone browser.
> 
> Some He-100s were fitted with 601a series engines.
> 
> ...



My book "Heinkel He 100 Record Breaker: Military Aircraft in Detail" has not come in yet, but the Schiffer book has where it states the D-1 abandoned surface cooling.

As for the wing radiator, would you mind posting s picture of what that would look like if you have one? Also, how well would thus work?


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## blueskies (Jun 4, 2015)

http://i57.tinypic.com/21lv2xe.jpg
http://i62.tinypic.com/14k9qhe.jpg
http://i59.tinypic.com/10nt89e.jpg
http://i57.tinypic.com/mtbbc1.jpg

The above photos are of A-0 series aircraft, often mistakenly called D-0 or D-1.

As for the wing radiator.
http://i62.tinypic.com/i2ixsg.jpg

This may have been nothing more then a trial installation.


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## SpicyJuan11 (Jun 4, 2015)

blueskies said:


> As for the wing radiator.
> http://i62.tinypic.com/i2ixsg.jpg
> 
> This may have been nothing more then a trial installation.



Interesting, what Versuchs aircraft was this?


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## Jaivan (Jun 4, 2015)

blueskies said:


> As for the wing radiator.
> http://i62.tinypic.com/i2ixsg.jpg
> 
> This may have been nothing more then a trial installation.



Propeller looks like VDM 12087A, so it might mean DB 605A or 601E experimental installation.


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## SpicyJuan11 (Jun 5, 2015)

blueskies said:


> That opening just below the spinner is to allow cool air into the engine compartment. It has nothing to do with the oil cooling system.
> 
> The 109e series had similar vents.



Not true. Hood remarks on page 63 that:


> The oil seeping out of the intake in the bottom of the nose ring hints at the possible location of a conventional, auxiliary oil cooler. No photographs in which this small Blockkühler is clearly visible have been found.



As for the wing radiator, nearly all Block II (commonly known as variant D) aircraft show the wing radiator on the port side of the aircraft. Hood even shows this on the plane's drawings on page 91, 92, and 93.


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## Shortround6 (Jun 5, 2015)

OK we have *possible* location of a conventional, *auxiliary *oil cooler.

Now of course the oil seepage can not *possibly* be from the prop reduction gear case or prop pitch change mechanism can it. 

If you are referring to the opening in the wing root on the port side inboard of the MG opening 







That is the supercharger air intake.

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## GrauGeist (Jun 5, 2015)

I really wish there were more detailed photos of the later production series - well, for that matter, it would be awesome of Heinkel had not lost all their documentation in the bombing raids...

By the way, Schnautzer came across a photo of an He100 that had a yellow nose (much like the early war Bf109) that I have never heard of nor seen. See it here: http://www.ww2aircraft.net/forum/aircraft-pictures/heinkel-he100d-1-a-43135.html#post1198913

This tends to make a point that the aircraft was truly an enigma...

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## SpicyJuan11 (Jun 5, 2015)

Shortround6 said:


> OK we have *possible* location of a conventional, *auxiliary *oil cooler.
> 
> Now of course the oil seepage can not *possibly* be from the prop reduction gear case or prop pitch change mechanism can it.
> 
> ...



Yes, that's the problem, we could say _"maybe, ok, could be, not sure"_ but that was my overall point because blueskies (seemed to me at least) say it definitely that it was not. But what I was talking about was this (this is the same photo the author wrote the caption to):








Now to the broad overall question of would it have been good to produce the He 100? The author has this to say page on 45):



> The differences in climbing speed and service ceiling seem marginal but the He 100 V4, by far the faster and somewhat lighter of the two, carried more fuel than the Messerschmitt. Moreover, as fuel and ammunition were consumed, overall weight would have decreased with a corresponding rise in speed. It might, therefore, seem reasonable to conclude on the basis of the figures that with or without a conventional cooling system the He 100, with the same eight of armament as the Bf 109 E, would have been an obvious choice as a replacement or supplement for the Messerschmitt.


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## GrauGeist (Jun 5, 2015)

Keep in mind that the early airframes were not armed or equipped with war dress (armor, self-sealing tanks) and lacked the retractable radiator that all added to a performance penalty.

However, the final (production) version still offered good performance and a range nearly double that of the Bf109

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## SpicyJuan11 (Jun 5, 2015)

GrauGeist said:


> Keep in mind that the early airframes were not armed or equipped with war dress (armor, self-sealing tanks) and lacked the retractable radiator that all added to a performance penalty.
> 
> However, the final (production) version still offered good performance and a range nearly double that of the Bf109



That's all very true, but the V4 (which the author compared on a table to the Bf 109 E on page 46) did have a retractable radiator.


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## GrauGeist (Jun 5, 2015)

Yes, V4 (WkNmr 1903) D-IRCN, had a retractable radiator, but it was smaller and still relied on the evaporative system. This airframe was the first to be test-fit for armament and was also one of the early series airframes that had the problematic under-carriage and small horizontal stabilizer.

It was one of the He100s sold to the Soviet Union, too.

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## SpicyJuan11 (Jun 5, 2015)

GrauGeist said:


> Yes, V4 (WkNmr 1903) D-IRCN, had a retractable radiator, but it was smaller and still relied on the evaporative system. This airframe was the first to be test-fit for armament and was also one of the early series airframes that had the problematic under-carriage and small horizontal stabilizer.
> 
> It was one of the He100s sold to the Soviet Union, too.



All very true. I'm going to try to contact the author to see if any built He 100's had a full combat dress as I cannot find anywhere that any of them did nor did not.


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## Koopernic (Jun 5, 2015)

The Germans didn't really have a problem replacing the Me 109 technically, they had a problem replacing the Me 109 production system which manufactured 34,000 Me 109, most in the latter half of the war. 

They were so fussy about keeping up production the Me 109G was produced without retractable tail wheel and with gun bulges which both could have been 'fixed' for a gain of about 10mph of precious speed and therefore manoeuvring power.

One can maybe shut down the Me 109 production system in favour of a new type once: say either the Me 262 or the Me 209 but surely not both.

The other problem is that the engines they needed to replace the Me 109 were the Jumo 213 and DB603 and due to decisions made in the late 1930s they just weren't ready till late 1943 or even 1944. Between 1937 and 1940 the DB603 was effectively parked on a low priority development program. This would be equivalent to telling Pratt and Whitney to 'park' the R-2800 while the R-4360 and R-1830 twin wasp received priority. Imagine US aircraft without the R-2800. For the RAF it would be equal to parking the Griffon for longer or the Sabre.

The Germans couldn't move on a Me 109 replacement till the DB603 and Jumo 213 were ready: that sets the pace.

Consider the replacements:

Me 309: it offered vastly increased range, a laminar profile wing, advanced radiator, and a very powerful armament. With the DB603G engine it offered a very high speed of 462mph it had some things stacked against it, minor handling issues: a slight yaw instability (usually cured by a loner tail or more fin area) and supposedly it was less manoeuvrable than the Me 109. I suspect this was really a power to weight ratio issue that came out of shortages of the DB603 and substitution of the DB605 and place little value on claims of high wing loading (which makes a aircraft much faster). I doubt these were serious issues so on the basis that it flew in June 1942 and allowing it 9 months to debug handling and a further 9 months to get into service the Me 309 could be in squadron use by January 1944.

Too late to buildup production. The Germans might handle introduction of a few new types eg Me 262 but would need to be cautious.

Me 209-II: It offered a larger wing area, ability to handline the big DB603 engine thus providing the range and fire power the Me 109 lacked. It supposedly took advantage of the Me 109 parts bin but it wasn't apparently enough.
The aircraft was a little slow, due to incomplete debugging of the always sensitive radiator airframe integration issues and the Luftwaffe gave up on it before Messerschmitt could dedbug.

Heinkel He 100: too small, it should have been produced as a photo recon to maintain the Luftwaffe's ability to photograph Britain.

Heinkel He 112: likely to have 'grown' better than the Me 109 due to its more powerull armament of twin 20mm guns but still too small post 1942.

Italian Serie 5 fighters:

Maachi 205: Too small, lacking in fire power, can not handle the DB603 engine. Not worth considering.
Fiat G.55: excellent can handle the DB603 engine in the guise of the G.56 could handle the DB603 engine.
Reggiane 2005: excellent can handle the DB603 engine in the guise of the R 2006.

However the Italian fighters weren't perfect: they weren't a big improvements in range, they had lacklustre roll rate (probably could be fixed) nevertheless they had no vices and were in production by early 1943. Had Italian Fascist Republic survived they could have been introduced with the DB605A engine, progressed to the more powerfull DB605AM and ASM engine followed by a clean transfer of production to the DB603 versions.
These aircraft would have been better than A Griffon Spitfire, Tempest V or P-51H Mustang in most respects: as fast or faster and likely more manoeuvrable and destructive.

The Germans however had an alternative: The Fw 190 could be adapted to the DB603 engine and the Jumo 213 engine. Furthermore the Ta 152 could be built with a great deal of commonality to the Fw 190 allowing a smooth transition. 

If we assume that DB603 engine development is not 'parked' we could get the following development schedule:

In early 1940, when the DB601A is producing 1050hp the DB605 might be producing 1600hp on the basis of power to weight ratio and swept volume.
In late 1941, when the DB601E is producing 1260hp on 1.3ata the DB603 might be producing 1900hp.
In early 1942, when the DB605A is producing 1350hp on 1.3ata the DB603 might be producing 1750hp but this is pessimistic as the DB603 is actually more mature than the DB605.

Historically the DB603A is in service mid 1943 on Me 410 and Dornier Do 217 but it is not regarded as debugged for 6 months (late 43 early 1944)
This is for service ready engines. It had been offered to the Luftwaffe as a 1575hp engine prewar. This changes Do 217 development and the development of a lot of aircraft.

The DB603 can be advanced by around 2-3 years and make a 1900hp Fw 190D8 available in qantity at the same time the Mustang is entering service and proably a 2200hp version with MW50 in early 1944.

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## GrauGeist (Jun 5, 2015)

SpicyJuan11 said:


> All very true. I'm going to try to contact the author to see if any built He 100's had a full combat dress as I cannot find anywhere that any of them did nor did not.


Of the D series, the three D-0 pre-production airframes were sold to Japan, the 12 production series, the D-1 were fully combat ready and were retained by Heinkel as "point protection" by being stationed at Heinkel's airfield at Rostock-Marienehe.

These 12 were also used extensively as propaganda and featured in various propaganda photos and "news" reports and either referred to as the He112U or the He113.


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## GrauGeist (Jun 5, 2015)

By the way, while this is a great discussion regarding the He100, I suppose Tomo would be alot happier if we got back in track with the Me209 

And by the way, He100 related, the Me209 V4 did had evaporate cooling during it's testing. But that system, much like Heinkel's, did not provide sufficient cooling and was replaced with a conventional system...


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## Shortround6 (Jun 5, 2015)

Part of the problem with _replacing_ the 109 _once it was selected_ was the investment in tooling and training. For example out of 647 of the Jumo 210 powered aircraft (C and D) only 62 were made by Augsburg. 123 were made by Focke-Wulf, 168 by Erla, 80 by Fiesler, 128 by AGO and 144 by Arado. The mix changed for the E models with Messerschmitt adding the Regensberg factory and Focke-Wulf dropping out. Arado, Erla and Fiesler stayed in the production group and Wiener-Neustader Flugzeugwerke replaced AGO (?). I don't know how much of the D production tooling carried over to the E but obviously there was a crap load of production tooling in existence for the 109 even in 1938. 
I haven't looked up F and G production but I am guessing it was similar (could be wrong) with many more plants/companies besides Messerschmitt tooled up for it. This could be a big reason for the 209-II trying to retain as much as possible of 109 structure and once the common parts had fallen below a certain point the project became unattractive.


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## SpicyJuan11 (Jun 5, 2015)

GrauGeist said:


> Of the D series, the three D-0 pre-production airframes were sold to Japan, the 12 production series, the D-1 were fully combat ready and were retained by Heinkel as "point protection" by being stationed at Heinkel's airfield at Rostock-Marienehe.
> 
> These 12 were also used extensively as propaganda and featured in various propaganda photos and "news" reports and either referred to as the He112U or the He113.



Of course, I know about the D series but as Short has pointed out earlier, did they have armor, self-sealing tanks, etc.?



GrauGeist said:


> By the way, while this is a great discussion regarding the He100, I suppose Tomo would be alot happier if we got back in track with the Me209




Yeah I suppose so, should I start a He 100 thread?


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## Shortround6 (Jun 5, 2015)

SpicyJuan11 said:


> Of course, I know about the D series but as Short has pointed out earlier, did they have armor, self-sealing tanks, etc.?



The Winter between the Attack on Poland and the Attack on France is a general dividing line between protected planes and unprotected in northern Europe (I don't know when the Italians got it) There are obvious exceptions and it does vary with your definition of "protected", some planes getting a steel plate behind the pilot several years earlier. British fighters in France being refitted over the winter or in the Spring of 1940. Many if not most of the 109s that attacked Poland in Sept 1939 lacked protection so the likelihood of He 100s built in 1938 having the full "suite" of protection ( self-sealing tanks, back armor and bullet proof windscreen) are pretty slim.

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## GrauGeist (Jun 5, 2015)

SpicyJuan11 said:


> ...Yeah I suppose so, should I start a He 100 thread?


There's already quite a few


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## SpicyJuan11 (Jun 5, 2015)

Shortround6 said:


> The Winter between the Attack on Poland and the Attack on France is a general dividing line between protected planes and unprotected in northern Europe (I don't know when the Italians got it) There are obvious exceptions and it does vary with your definition of "protected", some planes getting a steel plate behind the pilot several years earlier. British fighters in France being refitted over the winter or in the Spring of 1940. Many if not most of the 109s that attacked Poland in Sept 1939 lacked protection so the likelihood of He 100s built in 1938 having the full "suite" of protection ( self-sealing tanks, back armor and bullet proof windscreen) are pretty slim.


Interesting, thanks for the info!




GrauGeist said:


> There's already quite a few



Ok, but let me ask this one question: What if the RLM doesn't manage to increase DB production more than they did historically, but instead is extremely impressed with the He 100 and gives it the priority for DB 601's and tells Messerschmitt to make the Jumo 211 work with the Bf 109? How would this Bf 109 perform, especially compared to its historical equivalent, the Bf 109 E?


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## GrauGeist (Jun 6, 2015)

*if* the RLM decided that the He100 was to be introduced into service, I seriously doubt they would have the current backbone of the Luftwaffe derailed for an engine that's producing much less horsepower and would require a redesign of the mounting and plumbing, costing production delays.

It would be more likely that the RLM would either lean on Daimler to up production or have additional production from another manufacturer.

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## blueskies (Jun 6, 2015)

Regarding the streaking on the underprop vent.

1. there are many things that can cause oil streaking like that. It is not proof of a conventional oil cooler.

2. We have photos of planes with the exact same vent, in both size and shape, and photos of these aircraft with the engine cowling open. It is clear that at least these A-0 series did not have a conventional radiator.

3. Looking at the open cowl pics it is evident that there is very little space for much of anything.

4. Where is the exit for this oil cooler?

From these points I think one can ask the following questions;

If the A-0s that did not have an oil cooler had this vent, then what purpose did it serve? 

And if it did do something, as it must have, then wouldn't cramming a conventional oil cooler in there impair the original function of the vent? 

And why wouldn't this vent be redesigned if it was having an oil cooler added? This same vent went through multiple revisions on the prototypes, so why not change it now?

And just how did they fit this in? 

I think that on the whole, the most sensible estimation is the one that is most obvious: it is oil that could have been forced out of dozens of parts.

Until concrete evidence is shown, photo of the cooler installed on the plane, drawings of such an installation or documents from heinkel describing this. For now I view it as a lot of speculation over what amounts to very tepid evidence in a best case scenario.



SpicyJuan11 said:


> All very true. I'm going to try to contact the author to see if any built He 100's had a full combat dress as I cannot find anywhere that any of them did nor did not.



In He-100 Record Breaker?

There are photos of He-100s with streaking under the gun ports. There is a photo of a he-100 sitting in a hangar with the tripod mounted head armor visible.

There are also heinkel documents mentioning armament on test flights.



GrauGeist said:


> Yes, V4 (WkNmr 1903) D-IRCN, had a retractable radiator, but it was smaller and still relied on the evaporative system. This airframe was the first to be test-fit for armament and was also one of the early series airframes that had the problematic under-carriage and small horizontal stabilizer.
> 
> It was one of the He100s sold to the Soviet Union, too.



The V-4 was actually meant to be the pattern aircraft of sorts for the production series.

It possessed the following improvements;

Lighter stronger fuselage
New landing gear with the interchangable struts.
Wing condensers refined
Steam pipes in wings improved 
Many minor modifications to the aircraft and assembly method 
Retractable auxiliary radiator (meant for takeoff, taxi, climb and slow speed flight)
(4 gun wing development stopped with this machine)

There is one known potential photo of the V-4, which looks very much like an A-0(or D series if you will)

The Soviets purchased six He-100s - v1,v2, v4,v5,v6,v7 

Those last three are the first A-0 block of production, which was upgraded mostly to block II standards by the time they were sent to the Soviets. A-0 block II being what you call the D-1 series.

This is known by Heikel records confirming delivery.



GrauGeist said:


> Of the D series, the three D-0 pre-production airframes were sold to Japan, the 12 production series, the D-1 were fully combat ready and were retained by Heinkel as "point protection" by being stationed at Heinkel's airfield at Rostock-Marienehe.
> 
> These 12 were also used extensively as propaganda and featured in various propaganda photos and "news" reports and either referred to as the He112U or the He113.



There were 19-20 A-0 series machines making a total of 24-25.

Six went to the USSR as described above, and three went to Japan.

The Japanese received at least one block II series, which is known because of Japanese documents showing tests of a He-100 with the block II style tail.


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## SpicyJuan11 (Jun 6, 2015)

blueskies said:


> In He-100 Record Breaker?
> 
> There are photos of He-100s with streaking under the gun ports. There is a photo of a he-100 sitting in a hangar with the tripod mounted head armor visible.
> 
> There are also heinkel documents mentioning armament on test flights.



Yes I know about guns and ammunition being fitted, but I was referring to armor, self-sealing tanks, etc.

So what do you propose the vent is? Why did it continue to get larger (if you look on page 86 onwards, you'll see the V1 did not have it at all, the V8 did, and the A-0 block was even larger, it's hard to tell but the A-0 block II might've been even larger)?


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## Shortround6 (Jun 6, 2015)

a lot of planes needed a little "extra" cooling air around the engine or for accessories. Early BF 110s used the hole in the prop hub and tube for the "motor canon" has a duct for cooling air to the generator for example. The "motor guns" on the 109 and He 112 gave quite a bit of trouble do to over heating and various vents/cooling schemes were tried. Look at good Pictures of a Hawker Hurricane, Not only does the prop hub look like a rather 'sloppy' fit but there are a few bulges/scoops and holes (starter handle?) in the cowling. P-38s had little scoops to pick up air to be directed at the spark plugs, these are smaller and separate from the scoops used to cool the exhaust manifolds. AS has been said, the Bf 109 has a similar vent in the about the same position with oil cooler behind it. AS engine power went up they just made the oil cooler bigger not added extra ones.

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## spicmart (Sep 22, 2019)

Koopernic said:


> However the Italian fighters weren't perfect: they weren't a big improvements in range, they had lacklustre roll rate (probably could be fixed) nevertheless they had no vices and were in production by early 1943. Had Italian Fascist Republic survived they could have been introduced with the DB605A engine, progressed to the more powerfull DB605AM and ASM engine followed by a clean transfer of production to the DB603 versions.
> These aircraft would have been better than A Griffon Spitfire, Tempest V or P-51H Mustang in most respects: as fast or faster and likely more manoeuvrable and destructive.



What makes you think that the G.56 and R.2006 would be better than the Griffon Spits, Tempest V and P-51H. With DB 603 the G.56 was to reach a calculated speed of 685 kmh (not sure with or without MW50). That's as fast as the Fw 190D-9 without MW50 injection, with which the Dora achieved 704 kmh.
The Griffon Spitfires reached 714 kmh.
The G56 is not faster than the Tempest V which is at least as fast as the D-9 and all are are much slower than the final evolution of the Mustang which is the P-51H which does 784 kmh.
The G.56 most probably turns as good as the Griffon Spits and thus better than the other fighters (P-51H not sure as it was lighter than the D).
It does not match the D-9 in rate of roll, which is also an important part of manoeuverability.


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