The Fiat G 56

[Vincenzo]

And, finally, to the contrary of the general opinion that the "Regia Aeronautica" had a special treatment by the Fascist Government, most of the money spent in the Italian Armed Forces in the '30 did actually go to the "Regia Marina"

fiscal year budget in lire's milions Army Navy Air Force

1930/1 3230 1582 787
1931/2 3067 1626 775
1932/3 3068 1614 770
1933/4 2700 1440 720
1934/5 3036 1360 896
1935/6 7472 2927 2339
1936/7 9460 3491 3728
1937/8 6250 3041 4086
1938/9 7146 3500 4490
1939/0 15350 5291 7228

 

[Elmas]

Thanks, very instructing figures.
It has to be noted that in the years from 1935 onwards, Italy was engaged in three wars (Spain, Abissinia and Albania) that were extremely costly, expecially for the Army and Air Force, much less for the Navy, and the sums had to be employed to fill losses, rather than to get more advanced material.

 

[Shortround6]

Then Italian engine industry let itself slip behined in the vital 1938-1942 period though the 850kg 1500hp 18 cylinder Piaggio P.XII seems to have been an outstanding engine of low weight no fighter airframe was there to exploit it; this forced a quick catch up via liscence produced DB601 and DB605 which the Italian airframes seemed to exploit much better than the Me 109.

The 850kg 1500hp 18 cylinder Piaggio P.XII may have been a much better bomber or transport engine than fighter engine. In physical size this 53 liter engine was quite close to the Wright R-3350. the 1500hp is for take-off, rated power at 3,500 meters was 1350hp. It's low weight may have meant limited strength which held it's max RPM to 2100. The 176mm stroke didn't help either.

 

[vanir]

See Aeronautical research in Germany: from Lilienthal until today, Volume 147 By Ernst-Heinrich Hirschel, Horst Prem, Gero Madelung
Page 179 for info on Me 309 laminar profile wings.


Aeronautical research in Germany ... - Ernst-Heinrich Hirschel, Horst Prem, Gero Madelung - Google Books

Amazingly two researchers K.A. Kowalki in 1940 and latter with B. Goethert in 1944 reported on supercritical airfoils. This report saved Airbus a huge sum of money in a law suit Boeing had brought against airbus.

Me 309's belly radiator was retractable.

With Jumo 213A entering service in mid 1942 with the Ju 188E and the DB603E with the Me 410 in Jan 43 can't see what the holdup was with the FW 190D9 entering service in only November 1944 or making that engine available to G.56. Perhaps developing the emergency boost systems?

No 603E was fitted to an Me-410 mate, they all had the A. The 410B is reported third party as being fitted with the 603G but this is inaccurate, they were all fitted with 603A. There was quite a historical research project by a small team back in the old AAA IL2 days, I remember all the documented references in the release thread, I looked them up and downloaded some.

Interesting the 309 radiator retractable, is that like the He-113/100 prewar Messerschmitt competitor?

 

[tomo pauk]

The retractable radiator or 309 can be seen here:

http://www.aviastar.org/pictures/germany/me-309.gif

 

[krieghund]

Here's the original report from Kurfurst's site and a Word translate version.

It has references to lateral comparisons between some of the types that give an idea of roll capability.

 

[riacrato]

But they did that. The Fw190B/C began as a private venture by Kurt Tank's team at Focke Wulf, when the RLM finally tabled a höhenjäger requirement it turned into the Ta-153 project, which became the Ta-152 project and caused a requirement for an interim fighter that would enter production sooner using simpler modifications to Antons: the Dora.

The Fw-190C was basically an early version Ta-152C using a turbosupercharger instead of a two-stage blower. It was at an early stage of development, that's why it didn't enter production, not because nobody wanted it to but because it wasn't ready, the Ta-152C was definitely entering production at the end of the war. This is what it had finally matured into, and it is a heavily modified Anton so production is easily transitioned without serious loss of output.


What you are seeing here in action, what we all saw is the truth behind aircraft development. Most of the fighters flown during the war or entering production during the war were designed before the war. It just took that long to get them developed into production. There are only a relative handful of notable exceptions, like the Mustang which set design records. The Fw-190A you see suffered a prewar design setback when the planned engine went out of production. So it was still being designed at the start of the war. And generally aircraft which started development at the start of the war were lucky to make production by its end. Considering Tanks little shop of FW variants got up and running in 1942 it's quite an achievement to get a 2000hp fighter in production just as the war ended.

According to most course curriculums, in the 30s-40s in fighter manufacture, a new fighter took three years to get from blueprint to prototype, a new aero engine took seven years. The biggest thing the Fw-190C/Ta-152C was waiting on was the 603 engine development as a high powered fighter engine like the 603E or L. As for aircraft design itself, that started in 1942 for this particular concept given only variation on a theme, thus entering production in 1945 is running by standard measures.

The V13 flew for the first time in march / april 1942. It reached 663 km/h. The V16 reached 724 km/h at 7000 m in the summer of the same year, all with normal blower. Of course with armament the speed would drop, but it still had some refinement potential like integrating the oil cooler into the front. I guess the point I'm trying to make is, that it was a very bad idea to wait for the perfected Ta 152 an 153 and instead a less refined Fw 190 C could've been introduced in mid-to-late 1943, available for the critical months of 1943-44 and able to fight the Mustang on equal terms. Of course this is with hindsight, but imo it should always have been a priority for any nation to have a single-engined fighter using its latest engine technology available, so you don't open the enemy a window of opportunity to defeat your airforce (which is essentially what happened).

 

[vanir]

Sorry I might've not made a very good presentation. I do appreciate what you're saying, and you could very well be quite right. I tend to just stream thoughts onto forums, so what I was thinking was the Fw-190C experienced protracted development historically, it couldn't have entered production because Kurt Tank couldn't sort out a turbosupercharger/intercooler system for it that was reliable and delivered his performance requirements. At this stage it was also a personal project, the RLM hadn't bought in on it yet, they didn't until the Ta153 was drawn up for them and they wanted it to use the Fw190A production lines, so Tank had to simplify it to the Ta152 for the same role. What he did was simply continued his Fw190B/C project (höhenjäger) under the new title of Ta152, the B the H (switching bmw for jumo, I mean more in the sense of its design requirements and specified role, ie. high alt int and recon in two major variant series) and the C the C and B (escort-fighter, zerstörer, recon, jabo in three then two major variant series).

He did try to put the Fw190C into production, but he had to use a two stage blower intead of a turbosupercharger. And he went full kilt on modifications to refine it, ergo Ta152C. Mid-45 was the soonest, the earliest date this type of fighter could be put into mass production, the historical date which indeed it was about to.

 

[Elmas]

IMHO Fiat G 59 and B135 were not so similar, if examined under the skin.....and neither on the outher skin, always IMHO.....

The ancestor of B 135 was a family of French planes

from wich derived a lot of others

also Italian, of course

but certainly not the G 59.

 

[krieghund]

Thought I would post the G55 Data to contrast to the G56 Data I posted earlier. Also in the G56 data it would appear the DB603A was only cleared to 1510 PS and it still does 428MPH.

 

[jim]

Thought I would post the G55 Data to contrast to the G56 Data I posted earlier. Also in the G56 data it would appear the DB603A was only cleared to 1510 PS and it still does 428MPH.

That s something that i had never noticed ! 685Km/h with 1500 hp Db 603A! Even with Db 605ASM G55 would be extremely competitive and with lower wing loading !

 

[Denniss]

1510 PS @ 5700 m is the standard 30 minute rating for the DB 603A at full throttle height, the same with the G.55 and the DB 605A - 1250 PS @ 5800 m.

 

[vanir]

They're nice ratings those two engines, my favourite aero engines, given that it is at nice lazy rpm with big intake strokes. Great cruisers and climbers.

 

[Siegfried]

That s something that i had never noticed ! 685Km/h with 1500 hp Db 603A! Even with Db 605ASM G55 would be extremely competitive and with lower wing loading !

Changing from a DB605A at 1.42 ata to DB605AS increased Me 109G5AS speed by 24km and raised ceiling considerably.

Speed went from 630km/h to 654km/h achievable at higher altitude of 8km (low altitude performance remained unchanged)
(This is with a pair of Gondala guns which slow the aircraft 6km/h)

Changing the Me 109G14AM essentially a G5/G6 with a larger oil cooler and MW50 achieved a speed increase from
from 630km/h at 5km to 652km/h at 5km. About the same speed by available at lower altitude.
(This is with a pair of Gondala guns which slow the aircraft 6km/h)

The Me 109G14ASM achieved 668km, a gain of 38km/h over the Me 109G5/G6 (1.42 ata)

It would be fair to assume that the G.55 could also gain 38km/h (23.6mph) and probably more like 44km/27mph.

Thus a G.55 with an early DB605ASM (1.7 ata) shoud easily achieve 665km/h or 410mph and of course doesn't have to carry Gondala guns as 3 x 20mm and 2 x 12.7mm weapons are good firepower.

However as the engine developed to 1.8 as shown in the Me 109G10 (about 434mph, 34mph gain) and Me 109K4 (441mph 40mph gain).

My guestimates

Of course the main feature of the G.55 was that it could as the G.56 take the DB603 engine
0 G.56 DB605ASM engine = 413 to 428mph
1 G.56 DB603A engine = 426mph (1750hp sea level, FTH 5.7km) (only confirmed)
2 G.56 DB603E engine = 444mph ( 1800hp sea level, FTH 7.2km)
3 G.56 DB603EM engine = 444mph (2260hp sea level, FTH 7.2km) with MW50 much faster at low altitude.
4 G.56 DB603LA engine = 465mph FTH 10km two sage supercharger, no intercooler required.
5 G.56 DB603N engine = 480mph 2700hp-2800hp.

 

[vanir]

I'm afraid you have entirely the wrong impression of the performance tuning of the 605A compared to AS and in general the effects of taking what is in fact the very same engine and changing the outside diameter of the blower casing and playing with tuning conventions.

The AS motors have roughly 150PS less grunt at any combat setting than an A motor with the smaller blower at its own throttle heights. It's less efficient, but at least works up at 8km where a 605A has already reached typical service ceiling, its climb rate is hopeless at that height, the AS is real strong. You lose a little in order to put it somewhere else.

Next thing to know, take an engine on B4 and retune it to C3 with higher compression and you lower throttle altitude by about 1000m.
And MW50 is useless unless you use it at least 500 metres or more below the throttle altitude.

So in other words the AS has a throttle altitude of 1050PS max continuous at ~8km, 1150PS 30min rating at ~8km and a 1200PS military at ~8km.
Take the very same engine, slap MW50 and retune for C3. 1050PS max continuous is now at ~7km. WER the highest altitude you get any real benefit from MW50/overboost is 1500PS at ~6.5km.

That's about the same throttle height as a 605A at military on B4.

 

[Denniss]

Up to the critical alt of the DB 605A the 605AS-equipped G-6 was always a tad slower than the 605A-equipped G-6 - the larger supercharger required more power to operate (40 PS more at sea level). The aerodynamic cleaner nose helped to keep the speed loss small but it was still preseent.

BTW the power ratings of the german engines are in PS (metric) not in hp (imperial) - hp rating is always lower. 1750 PS = 1726 hp - this is always a major source on confusion in books as they often used a 1:1 conversion from PS to hp, then kW conversion based on the wrong hp ratings.

 

[vanir]

My point was the A series of the 605 family are A/M, AS/M, then the D series are DB/C and ASB/C because they use two distinct series of piston crowns and chamber design allowing for higher pressures on B4. It was all about the fuel type. They wanted B4.
Putting MW50 designations aside the differences A, AS, D describe three different blowers on the 605x base engine.

So it's two different motors, three blowers and two fuel types is what all these describe. The earlier motor can only handle 1.4-1.7ata. The later 1.5-1.98ata since it solved the problem with piston burn throughs.

So when you say the AS was better than the A, problem is they both use the earlier base engine. If you're talking about the later base engine, the DB/C and ASB/C only have about 500m throttle altitude between them at maximum continuous and at higher engine settings they level out. Using the 603A blower on the DB/C gives it a more efficient cruise range and better fuel economy, an exact opposite of what putting a 603A blower on an A motor does.

 

[Siegfried]

What speed would a G.55 with an DB603ASM be capable of?
Wikipedia states G.55 speed as 623 km/h (337 kn, 387 mph (417mph with WEP)) at 7,000 m (22,970 ft)

So where does the WEP figure come from, an DB605AM? There is no way going from military power at 1.3 ata to notleistung at 1.42 ata (WEP) will take the aircraft from 386 to 417. This I suspect is data for an ASM.

What speed would we get with the Me 109K4's engine: the DB605DCM?

 

[vanir]

Well I think you're asking the right question there because this brings up the point that you don't go by top speeds to guage performance. The engine setting used for a top speed guideline (and it is a highly circumstantial guideline), simply isn't the one used in combat and it simply doesn't reflect the performance of the aircraft either through its envelope or during combat regimé.

Always use maximum continuous to compare the guts of regular flight performance, and use military power to compare speed/climb performance during extended combat. WER/sondernotleistung are used for escaping combat, not fighting. If you don't want to blow your motor, WER use during combat is very selective and very conservative. You're at military for 85% of the time, doing cooldowns 14% of the time and give yourself an extra WER boost that 1% of the time you can unload G and not waste it. Because right after you use WER the cooldown is a serious issue if you're still in combat.

Anyway it's the industry convention. You compare always with maximum continuous and military settings, WER ratings often aren't even generally quoted when surveying new models. It's a bonus extra.

So the best of the entire 605 series according to the figures I've already quoted is the ASB motor without any question (it's a DB with a 603A blower instead of a D series blower, just like the AS is the same blower on a 605A). It has DB performance with better cruise performance and probably a 50km range increase just by switching the engine over, due to that fantastic cruise the ASB has really, just a purring 1200ps at max continuous 6.5km and a lazy 2300rpm with a cool temp guage, you can do it 'till the tanks run dry and should be around a comfy 300mph in a clean light fighter like an Me-109 or similar.


And keep in mind adding an M to the DB/C or ASB/C is superfluous. They're both designed to MW50 so there's no designation, because you can't hurt one by putting in a kit. You have to designate AM/ASM because if you get an A and put a kit in it, you'll blow the motor immediately. It has to be converted to C3 for the MW50, but was always intended to be developed back to use B4 with MW50 (which didn't happen until the D block). So they said AM/ASM and A/AS are different. But DB/ASB and DC/ASC are different. Yet AM/ASM are the same, A/AS are the same (just blower changes), and DB/ASB are the same, DC/ASC are the same (same blower change). But what is different about DB/ASB and DC/ASC that has to be designated is again, C3 must be used. So they specify B (uses both fuels, preferred motor), and C (retuned to use C3 only, hotrod interceptor for small unit deployment). There is no need to mention M designation because they both use MW50 without a problem right out of the box.
So MAG designations only go, A-1, AS, AM, ASM, DB/C, ASB/C. There are tuning changes between fuel types. All D blocks can use MW50.

 

[krieghund]

Here the DB603A chart