Replace Me-109 with Me-155?

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DonL said:
Please post that chart of the PzGr. 1940.
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This is looooong overdue, my apologies. But here are the figures for German tungsten shells


Kris
 
Riacrato,

The Planes of Fame operates a Flugwerk Fw 190 powered by an R-2800. It has the same cowl opening as stock, but now sports two very samll underwing oil coolers in addition to the coolers around the inside of the front cowling. They overheated on the first flight and have never done so since fitting the small outboard oil coolers.

It is owned by Rudy Frasca of Illinois and fies 1 - 5 times per year quite reliably. I have no idea how it would fend as a regular daily flyer.

Don't know of a force-cooled R-2800 unless it was buried inside a wing or fuselage ... and I'm not aware of one so-configured at this time. I'll look!
 
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Hi Greg,

I know of this FW, I've seen a few videos of it a year or so ago. It seemed to have a bulge at the underside of the cowling, but looked close enough to the real thing.

It seems only logical that it would need some additional cooling provisions going from 14 to 18 cylinders. The BMW801 also had the fan, but then also had the armor inside the cowling so hard to compare on paper, i guess. Any pictures of those radiators? I also wondered where the supercharger air intake is.

It'd be interesting to know if it's ever been put to the edges of the R-2800s performance envelope and how the engine and bird handle that. Not to be nitpicking, it works as has been proven, but a replica bird in civilian use is different from a war machine. My point in this whole thread (iirc) was that reverse engineering the R-2800 and using it instead of the Jumo 213 was a nonsense idea.

The wikipedia article on the R-2800 mentions a fan-cooled prototype able to give 2800hp, that's where I think I got the info from. Don't think it was ever produced though.
 
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The engine on the XP-47J appears to be fan cooled.



How it was done I don't know. P&W lists two engines for the XP-47J, one is the standard -57 engine used in a lot of other P-47s and the other one is one-off that was shipped with-out a nose case and later fitted with a standard reduction gear nose to convert it to a -57.

Unless we know the model of the R-2800 in the Flugwerk Fw 190 and the operating conditions/limits we really don't know much. A post war commercial engine from a DC-6 was good for 1800hp at 6000ft and 1600hp at 6000ft MAX continuous. Given the FAA speed limits at low altitude and the rare flights (if any) at higher altitudes one of these engines provides more than enough power at way less than full throttle (cooling load) to power the FW 190 to a flight performance that any sane or legal pilot would need.
These engines also use a different form of construction than the early R-2800s ( different cylinder barrel and heads with much more finning/cooling capacity).

But for all I know the Flugwerk Fw 190 uses an old Martin B-26 bomber engine with the old cooling fins and lower power limits and is driven harder. Right now we don't know one way or the other.
 

The important streamlining in a radial-engined installation is on the inside. Since many of the German radial installations seem to have required cooling fans, I tend to think that shows that the Americans did a better job of designing their radial engine installations than the Germans.

As for the outside, do remember that piston-engined aircraft are too slow for nose shape to make a significant difference in overall drag, so long as there is no separation in normal conditions.
 
Many? There were few German radials to begin with, with many being more or less direct copies of American designs of the thirties. And I don't think the fan-cooling is shoe-horned in as an afterthought when cooling proves insufficient, rather it is designed around that principle from the start. The reason behind being that the closer cowling will be more aerodynamic and more than offset the loss of power. Whether or not this proved to be wrong or true is not for me to judge, but BMW certainly wasn't the only one thinking along those lines, as the XP-47J and the Ash-82 that lowered the late Lavochkins show.

And I wouldn't say that the nose shape was not important enough to matter. Far from. Even the windshield can have significant impact as can be seen by the Spitfire drag analysis posted on this forum somewhere.
 
There is nose shape and there is nose shape. And some of the radial engine installations may have caused separation.

The Curtiss Hawk 75-87 family being an almost classic example. The Early P-40 was considered to have 22% less drag than the R-1830 powered P-36. And the R-1830 powered planes were a bit faster than the R-1820 powered planes IF THE ENGINES WERE OF EQUAL POWER. which they often were not, especially at altitude.
You also have to consider what was actually known at the TIME vs what is known now.

The XP-42 ( a P-36 with and extended shaft and a pointy nose)





went through over a dozen nose configurations searching for the solution.

This was the fastest radial engine Curtiss Hawk built, a re-engined P-40.



But then it used a TWO-STAGE supercharger and hit peak speed at over 22,000ft so comparing speed to P-36s at 15,000ft or under has a real difference in drag.
 
riacrato said:
And I wouldn't say that the nose shape was not important enough to matter. Far from. Even the windshield can have significant impact as can be seen by the Spitfire drag analysis posted on this forum somewhere.
Click to expand...

So the Spitfire wind screen is quite draggy. Anybody know how draggy the canopies of other fighters were in comparison?
The one of the Me 109 seemed quite bad also.
 
I believe he is referring to the fact that the external bullet proof windscreen was worth about 6mph in top speed in the 360mph speed range. That is leaving the rest of the canopy alone. Entire change was on the "nose" of the canopy. Sharp edges may have caused breakdown/separation of airflow.
 
Hi Riacrato.

The R-2800 Fw 190 was raced for a couple of years at Reno in the Bronze Class by John Maloney after the small external oil coolers were installed. Unfortunately it had a DC-3 propeller at the time so the 2,000 HP engine was driving a 1,200 HP prop. Didn't get but a tad over 300 mph. As of NOW however, it has a DC-3 Glider tug prop that has very wide chord baldes and goes MUCH better than before. The aircraft is currrently over at the Palm Springs Museum for awhile but, when it comes back, I'll be happy to check the dash number of the engine. The operating conditions are whatever the stock dash number calls for ... this is NOT a hopped-up race engine. It is a stock R-2800 with no fan blades on the spinner backplate. I'll ask Matt Nightengale who built it. He is a museum member and I see him on occasion.

It is also a Flugwerk plane, so the g-limit is on the order of 4.5-g's or so ... not a wartime limit rating. The FLugwerk airframes lack the cannon mounts in the upper cowling and aren't nearly as strong as the real Fw 190 as a result. It isn't the wings ... it is the support (or lack of it) for the egnine mount. In the real Fw 190, the cannon mounts acted as partial support for the upper engine mount.

None of the R-2800's above appear to be fan cooled to me, including the XP-47J, and I still don't see the fan that is supposed to be there. There is no room on the driveshaft of an R-2800 for a fan ... unless it had an extended driveshaft or the "fan" is just blades on the back of the spinner backplate as on the Fw 190. If so, you'd think the blades would be visible.

Edit: I just zoomed in to 400% and you CAN see the fan blades. They must be attached to the spinner backplate.

The scoops under the front cowling are oil cooler inlets on each side and a central inlet for the turbocharger fresh air or intercoooler air depending on installation, just as on a standard P-47. The entire bottom 1/3 of the plane is nothing but air duct. The fresh air and exhaust go back to the turbocharger, and the compressed air (boosted induction air) goes back forward to the carburetor, either with or without being intercooled.

Hey Riacrato, let's start another thread for this line of discussion and let this onhe get back to the thread title. OK? Since I just answered here, if you want to discuss it, maybe start one? In any case, I'll check on the R-2800 dash number and talkw ith Matt Nightengale as I said. Might tale a week or longer. In only get there once a wekk.
 
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On 12.08.1944 the Erprobungsstelle Rechlin submitted some proposals to the Technisches Amt of the RLM on how to improve upon the Me 109K-4's performance significantly.
Eight options were outlined:

a) change of wing inclination (is this the correct term?)
b) smooth surface structure
c) aerodynamically refined canopy
d) improved air intakes
e) improved super charger air intake
f) enlarged oil cooler (0,400 m^2, normal for K-4: 0,360m^2)
g) new exhaust nozzles
h) aerodynamically refined engine cowling

All these changes it was estimated would have brought a speed increase of about 60 km/h, the equivalent of about 200 PS more engine power.
Though the efforts to apply these modifications into production were deemed too much,
one such plane was build at Rechlin and underwent testing presumably from 20.10.1944 on, the fate of it being unknown.
The speed achieved would be as good as or better than its allied counterparts (latest variants).


As for the planned built-in-wing armament (another thread, similar topic) of the K-version in summer 1943 Messerschmitt commissioned the Wolf Hirth GmbH to build a wooden wing that could house the MK 108 plus ammo.
The construction and build of it proved uneconomical though.
For the connection rib and around the wood chord metal still had to be used.
Furthermore wood could not be used for the complex shape of the landing gear recesses.
Breaking tests also showed a need of structure strengthening.
Great difficulties for the merge of wood and metal parts were expected.
Nevertheless an experimental build of gun in wing was performed in November 1943 and work ended 28.12.1943.
But at that time metal wings for the Me 109 K were already chosen (Why That?)
So the planned production of 3995 wing pairs until summer 1945 was omitted.

Sources: "Messerschmitt Bf-109 G/K" Flugzeuge Profile 5; Manfred Griehl
 
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Volksjäger program specifications were issued 10 September 1944. I suspect that ended any chance for significant change to 10 year old Me-109 program.

1942 Me-109G was probably the last chance to make significant changes to Me-109 design.
 
If they didn't correct the control column fulcrum issue, the extra speed would be good for nothing. The Bf 109 was a slow to medium speed dogfighter and when going faster than about 340 mph, the ailerons and elevator were almost set in stone. Without correction in the leverage ratio, this speed would only be for straight line running either to or from a fight, as most fast Bf 109's were doing. They also seriously needed to fit a rudder trim tab. I like the bubble canopy on the Bf 109 fitted with a R-1820 egnine as a prototype. It was far and away better than the stock windshield-canopy setup.

The Bf 109 had growth potential in it yet, but Germany lacked the time to take advantage of the fact. I'm sure it could have evolved at least a few more times before being done. I can think of a new airfoil, wider landing gear, and even slightly more wing area with commensurate tail attention. The basic airframe was solid as were the engine and propeller.

The term you are looking for above is wing incidence. It is the angle of the chord to the fuselage level line. It determine if the plane flies level, nose up, or nose down. If you've ever seen a B-52 flying at low level as in an airshow, you know it flies nose well down when low. It flies essentially level at 50,000+ feet.
 
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GregP said:
The Vf 109 was a slow to medium speed dogfighter and wehn going faster than about 340 mph, the ailerons and elevator were almost set in stone.
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It was a power fighter and I have yet to see solid evidence that the controls were beyond control at high speed. The only sources we have for that are Allied test pilots who were completely biased.


Kris
 
Were they biased or was it that it took much more muscle than it did in a/c they were used to flying?
 
Were the test pilots "biased" or are people getting pissy because German technological superiority is being questioned? The post-war test pilots had absolutely no incentive to denigrate any part of the performance or handling of the loser's aircraft. They did, however, have a lot of experience providing objective data to flight test engineers and aircraft designers so that aircraft could be improved, and that would include contributions resulting from the flight test of captured aircraft.
 
If you have yet to see that Civetone, then you aren't reading many of the same flight reports about the Bf 109 that I have read. It is virtually every flight report I have seen.

1) I don't read German, but the few former Luftwaffe pilots we have had speak at the museum said it was true.

2) We have an Hispano Ha.1112 that several of our pilots, including our president and chief pilot, have flown and it has the same characteristics. The airframe is essentially a Bf 109G with a Merlin in front.

3) A Bf 109E was restored at Chino and now flies out of Niagra Falls. It has the same characteristic according to the pilots that initially flew it and fly it now.

4) The Planes of Fame has a complete Bf 109G-6 that is flyable, but doesn't fly anymore these days since we don't have a spare engine for it. When we operated it, if exhibited the same characteristics according to the pilots who flew it.

Seems pretty clear to me.

I absolutely love the sound of the DB 6000 series engines and wish our Ha.1112 has a DB in the nose instead of a Merlin, but they aren't anywhere near reasonably-priced these days and we don't fly any plane that we don't have at least two engines for. When they break at an airshow, you HAVE to be able to fix them and fly them home. So our Bf 109G-6 is on display until and if we can get another engine so we can add it to the flyable palnes we operate. It would require some work at this time, but it is VERY complete.

Not saying you are wrong. I am saying I have a LOT of evidence, including first-hand flight reports from pilots I know and trust, that points to the reported flight characteristics as being in line with the reports that make the claims.
 

All proposals which might have increased the maximum speed but would have done little to improve high-speed handling. Had the K-6 with wing armament been produced it was more than likely that extra weight of the MK 108s and ammo would have increased lateral instability, particularly when turning. For example, when III./JG 26 was issued with K-4s with MG 151/20 wing gondolas they were universally hated because they turned the 109 into a wallowing cow at higher altitudes.

The 109 was past its use-by date without extensive modifications and an indication of this is Program 228, issued on 15 March 1945 by Albert Speer, which, amongst other things, recommended that production of the 109 and DB605 be stopped immediately in favour of the Me 262, Ar 234, He 162 and Ta 152. The Ta 152C series was a better bet for a fighter which could compete against fighters (eg: P-51H, Tempest II, P-47N, La-9 11) the Allies might have been able to field had the war continued into 1946
 
Presumably these speeds are indicated airspeeds or possibly calibrated airspeeds. At 25,000 ft., you won't be able to get even a Bf 109K beyond about 310 mph IAS except in a dive. Thus the Luftwaffe was being logical in 1942 by building the Bf 109G for fighting at high altitude and the Fw 190A for low altitude. Naturally, it didn't work out like that and the Bf 109G did a lot of fighting at low altitude. Thus it was sensible to go a single fighter as soon as they had an engine for the Fw 190 family that gave good power at high altitude but the Bf 109G probably outperformed a Fw 190A high up where it also had good handling.
 
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I fully understand what you are saying cherry blossom and agree that the Bf 109 was generally in the 350 mph and under IAS category, with the very high reported speeds being the difference between IAS and TAS. However, at speeds above 310 - 320 mph or so IAS, the Bf 109 was pretty much becomming a tough plane to fly. The good 109 pilot would attempt to get his opponent to fight at 180 - 290 mph, right in the realm of the best 109 flying characteristics. Best combat speed was right in the mid 200 range, with 250 mph being the point where NOBODY wanted to fight a Bf 109.

Coincidentally, these are the exact speeds where the majority of early Soviet planes operated, and they were fighting the Bf 109 at its own game. History will show how successful the Luftwaffe was at that. Once the Soviets and the rest of the Allies started operating faster fighters, the heyday of the Bf 109 was over and the attrition began. To be sure, the Bf 109 was adangerous opponent to the end. While not at the top of the game anymore, the better pilots were very familiar with it and could give an excellent account of themselves anytime if not overrun by sheer numbers, which they frequently were. At the end, they were short of pilots, fuel, and propellers, and simply could not field many fighters against the many-plane sweeps the Allies were flying.

I know there are people who claim the Germans were not short of fuel, pilot, or props, but they are wrong. Germany had the fuel but, if you can't get it to the airfelds where the planes are, of what use is it in a tank? Germany had many pilots near the end buy most were very green and had almost no combat experience much less time in the aircraft. They might also have had the props but, again, it they don't reside on the end of the DB driveshaft on a Bf 109, they are useless as wall decorations.

I am not a 109-basher, but it was what it was. As for its standing in history, I am one of the guys who thinks the Bf 109 ranks near or at the top of the chain for actual combat accomplishments, even though the war was lost from the German side. It ALMOST took the world and DID take the world's air forces into their worst nightmare. I KNOW the Fw 190 has its fans, but the achievements of the Bf 109 make it the top German fighter in my book, despite the fact that it SHOULD have been replaced in 1942 or 1943 and DID have glaring deficiencies that could easily have been corrected but never were.

Truly a plane that was more than it's paper performance ever suggested it would be and its debut gave NO hint of the achievements to come.
 
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