Time Machine Consultant : Maximizing the Bf-109 in January 1943

[DerAdlerIstGelandet]

This is simply not true. They had heard about the American plans for a new superbomber and they noticed that the B-17 operated at altitudes which were too high for the Fw 190.
Also by 1943 they had experience with the P-38 which could escort bombers at least to the west of Germany. The writing was on the wall !

Also, Galland told Goering in 1943 that American fighter planes had reached Cologne. Goering told him to stop this nonsense as this was simply impossible. After which Galland told him "I have seen the wrecks with my own eyes, and what's more, soon they will fly even deeper inland" after which Goering went into a rage and gave him a direct order to stop talking about it
So yeah, when talking about German leaders, you are in fact right!

Good call. I actually forgot all about that conversation. It just goes to prove the point how out of touch with reality that Goering (Or should we call him Herr Meier? ) and other High Command officials really were.

Either way good stuff everyone. This has finally turned into a good thread with good information. See how easy and better it is when people get rid of the chips on their shoulders...

 

[drgondog]

Drgondog, I think that is not giving the German intelligence enough credit. The Germans did have figures on the coming American aircraft production and they had captured P-38s and P-47s back in 1943. So they knew that these aircraft could enter Germany. They also knew that soon improved versions would be coming ever deeper into Germany. I was wrong to say Cologne, it was Aachen in the late Summer of 1943 when Galland and Goering argued. Goering couldn't and wouldn't believe there were American fighters over Germany as he had given his word to Hitler. But even if the Ruhr area is not Berlin, it is definitely a horrible idea that this main German industry zone would now be bombed with fighter escort. Perhaps not in early 1943 but at least by mid 1943 the Germans - except for the top top leaders like Hitler or Goering - realized what was coming.
In any case the development of a Fw 190 achieving an altitude of 40,000 feet had already been ordered. Was this only for the high altitude intruding Mosquito's ?

I still don't understand this comment. Both the MkVII and Mk IX were easily capable of 40,000 feet and doing it in 1942 so why would tank have even a remote notion that no single engine figter could reach 40,000 feet?

The Mosquito and the Spitfire variants from Mk VII and Mk IX forward, were real and in their face - and by and of itself a good reason for a 40,000ft capable interceptor - long before the B-29 became operational


And as I said, Tank believed a single engined fighter could not get to this altitude. And he was right. It took until early 1945 before he could come up with one which could.

Kris - without belaboring the point - the very first P-47 captured by the Germans was November 7, 1943 - exactly 66 years ago. YF-U "Beetle" 42-22490 P47D-2RA flown by 358FS/355FG pilot Bill Roach who got lost and landed intact near Caen. The P-38G was captured on June 12, 1943 in Italy but the Germans didn't geet much data because the Italian fuel grounded the airplane.. It did not have a wing tank to clue the Germans into the probabilities of very long range escort.. and the first operational flight of the P-51B-1 was to be flown three weeks+ later.

Sure. But I am talking about 1938/1939. These engines were still far away.
Also, a radial engine would probably the logical choice as both have distinct advantages. The BMW 139 or 801 could be used by bombers or attack aircraft.

I get that now - but I thought this conversation was about 1943?

Kris

I have zero clue what German intel had on the RAF experiments with a Merlin Powered Mustang in 1942, nor do I know what they believed about the B-29 but if they knew about both and expected them in 1944 they really screwed up - which is hard to believe - regarding threat analysis and meeting them with priority developments.

 

[Kurfürst]

The real problem was the lack of a good supercharger set-up on any production German engine before 1945.

A single stage supercharger just cannot supply air at a high enough pressure to maintain power at 25,000-35,000ft no matter how many gears or how it is driven.

Doesn't matter if you are using a 42liter 14cylinder engine or a 44.5 liter 12 cylinder engine or a 47 liter 18cylinder engine.
The DB series did have several slight advantages which added together ment it had several thousand more feet of rated altitude than the BMW 801 but it still wasn't going to compete with the two stage superchargers on the allied planes no matter how they were driven, Mechanical or turbo.

This is not quite true - people tend to think of two-staged superchargers as some kind of magic wand, but in reality, the power outputs of the high altitude DB 605AS and D engines with the enlarged supercharger was identical to that of the two-staged Merlin 6x series and the licensed Packard 1650-3/7 that drove the Spitfire VIII/IX and the Mustang B/C/D. This is easily confirmable from an overlay of power curves for the respective engines.

Also the rated altitude of the earlier DB 605A and the BMW 801 were similiar, around 19 000 feet. The plus IMHO for the Bf 109 was that it was considerably lighter than the BMW 801 powered FW 190s, with the added advantage of a less draggy installation of an inline vs a radial and thus was effected much less by the gradual loss of power above the rated altitude. Similiarly, the gains from the adoption of the inline Jumo 213A for the FW 190D were related to the same factor of decreased drag - the Jumo powerplant neither offered more power or higher rated altitude compared to the radial BMW 801.

It also worth of noting that the later, two staged Merlin 66 / V1650-7 were geared for lower altitudes compared to the earlier ones, reflecting operational requirements, to around 16000 feet.

 

[riacrato]

.
.

1. The flak 38 is not an aircraft gun. It is way to heavy and has a poor rate of fire. It's range and accuracy aren't needed in realistic scenarios. It is a very poor choice for a fighter armament.

2. The MK 108 barrel they chose was the longest they could without the risk of blowing up the gun. If you increase the barrel length the chamber pressure rises.

3. Yes the MK 108 is the holy cow.

4. Jumo 213 Jumo 222 were also in development. Of course the latter turned out to be a failure but I guess you with your infinite knowledge can predict that in 1937 eh?

"And DB 601/605 remained with same power from mid 1942 to mid 1944 (and still under the main rival, Merlin 60 series). I guess RLM failed to force DB to do that, don't you agree?" Wtf is this even supposed to mean. What do the development problems of the 601/605 have to do with anything I said?

 

[tomo pauk]

Didn't wanted to bee to harsh, sorry

1.Since we're mounting it to aircraft, it becomes aircraft gun. For it's power (134g @ 900m/s) it's not over weighted, and it's surely lighter then MK 103. My guess is that higher accuracy power is always a good thing. Since we're about to upgrade (perhaps only up-neck) to 25mm (as I've said, 200-250g @ 700m/s) it would be a killer gun as a motor cannon, or two for FW-190 outer wing mounting.

2. Since MK 108 had about 1/3 of propellant of 103 had, my guess is that chamber pressure was pretty low. So they could mount a longer barrel if we took only pressures in account.

3. Again: nice.

4. DB-603 was reality in 1942. Jumo 213 was reality in 1944, with same power. What would you choose in 1942?

My tirade shows that RLM was not properly pushing DB to increase power of 601/603 line from 1942-44 as you stated:

The DB603 was no longer funded because the RLM needed DB600 series engines now. So since they already had promising projects in that engine class with other companies they tried to force DB to continue on producing and improving the engine they needed really badly at that point.

...or you are wrong about that part in bold.

 

[Shortround6]

This is not quite true - people tend to think of two-staged superchargers as some kind of magic wand, but in reality, the power outputs of the high altitude DB 605AS and D engines with the enlarged supercharger was identical to that of the two-staged Merlin 6x series and the licensed Packard 1650-3/7 that drove the Spitfire VIII/IX and the Mustang B/C/D. This is easily confirmable from an overlay of power curves for the respective engines.

Again, "This is not quite true" The Allied liquied cooled engines,being smaller needed higher boost to develop comparable power. This ment that they needed higher pressure ratios from their superchargers to make rated power than the German engines but it does not mean that the Germans could use single stage superchargers at any hight they wished to. I know you didn't say they could but let us look at the examples you gave. For the DB 605AS to maintain 1.42 ata to 26,000ft it's supercharger needs just about a 4:1 pressure ratio which is actually quite good for a single stage supercharger. THe Merlin -3 engine because it is operating at 2.04 ata at military power (NOT WER) needs a supercharger than can supply a pressure ratio of 5.74:1 at about the same altitude.

Now to go any higher the Germans are either going to have to get more than 4:1 out of a single stage or add a second stage. Since a second stage doesn't add but mulitplies the British could have been using (in therory) a pair of 2.4:1 compressors. giving them a lot more potential for higher pressure ratios.
Practical factors that come into play are the higher the boost the hotter the air entering the engine and the more danger from detonation. However using two stages to get the same pressure ratio overall means less actual power used in the compressors and less actual heating of the air for the same pressure ratio. this is without using an inter/aftercooler. However it does help explain why inter/after coolers are almost manditory on two stage engines.

Pleae do not confuse the Military Power rating height for the WER height. THe former is limited more by the pressure ratio of the supercharger while the latter is limited by the volume flow of the supercharger.

Similiarly, the gains from the adoption of the inline Jumo 213A for the FW 190D were related to the same factor of decreased drag - the Jumo powerplant neither offered more power or higher rated altitude compared to the radial BMW 801.

Could you please give some sources for this. The ones I have seem to show the Jumo having about 10% more power than an 801D at 18,000ft. But these sources are old and may not be accurate.

It also worth of noting that the later, two staged Merlin 66 / V1650-7 were geared for lower altitudes compared to the earlier ones, reflecting operational requirements, to around 16000 feet.

Again, while it is true the gear ratios were changed do not confuse WER ratings with Military ratings. IF a particular model Merlin could supply 18lbs of boost at certain altitiude and was later re-rated for 20lbs of boost the supercharger could not supply 20lb at the same altitude as it could supply 18lbs so the "rated altitude" fell. THe engine could still deliever the original boost and HP at the original altitude however.

If The Germans had developed aircraft with better altitude perfomace I don't think itwould have been any great trick to go back to the supercharger gearsets used in the -3 type engines.

I don't mean to pick on the just the Germans here. The Napier company never got a two stage supercharger on the Sabre and Bristol never really got a two stage engine going either. While their larger engines had a head start in sheer power neither one really showed a much higher altitude power peak than the much critisized single stage Allison

 

[riacrato]

Didn't wanted to bee to harsh, sorry

1.Since we're mounting it to aircraft, it becomes aircraft gun. For it's power (134g @ 900m/s) it's not over weighted, and it's surely lighter then MK 103. My guess is that higher accuracy power is always a good thing. Since we're about to upgrade (perhaps only up-neck) to 25mm (as I've said, 200-250g @ 700m/s) it would be a killer gun as a motor cannon, or two for FW-190 outer wing mounting.

It's still way too heavy and the ROF is very poor. Anything below 600 rpm you can pretty much forget about unless you pack a whole lot of them into your plane and the flak 38 only has 450 rpm. Heck you might as well take the MK 103 then (440 rpm), at least its more powerful.

2. Since MK 108 had about 1/3 of propellant of 103 had, my guess is that chamber pressure was pretty low. So they could mount a longer barrel if we took only pressures in account.

I'm pretty sure if they could they would've done so.

4. DB-603 was reality in 1942. Jumo 213 was reality in 1944, with same power. What would you choose in 1942?

Jumo 213 powered Fw 190s flew in 1942. The DB 603 still had serious teething problems even as late as late 1943. So it surely wasn't as perfected as you make it.

My tirade shows that RLM was not properly pushing DB to increase power of 601/603 line from 1942-44 as you stated

Sorry but I don't see the logic in that. As soon as someone puts you under pressure you magically solve all problems in no time? That doesn't make any sense. And I also said develop, which not only means increase in power. The most important thing at the time was manufacture though, which I clearly stated.

 

[Civettone]

Drog; I'm sure I wasn't clear on this: I meant to say that the requirement was to get to 40,000 ft RAPIDO ! The requirement was for a high altitude interceptor. The required performance - I don't know how many ft/min or how many min to 40,000 ft were stipulated - was high enough to believe that only a twin engined interceptor à la Lightning would have been able to do so. Of course several aircraft could reach 40,000 ft.

Qnd yeah, I'm also getting a bit confused as to what we're talking about. For some subject such as the Fw 187 we are talking about the late 30s, but for other subjects like a possible Bf 109 replacement we are in 1943. And early 1943 to be exact.
I agree that the Luftwaffe felt it was still on top of it by early 1943. This only changed dramatically after the Summer.


Kris

 

[tomo pauk]

It's still way too heavy and the ROF is very poor. Anything below 600 rpm you can pretty much forget about unless you pack a whole lot of them into your plane and the flak 38 only has 450 rpm.

450 rpm means 10 rounds in 1,5 seconds, so more then enough to bring a bomber down since 'my' gun is 'too much accurate powerful (as you state)'. But just to comfort you, the engineers would tune it to fire faster our new 25mm ammo, okay?

Heck you might as well take the MK 103 then (440 rpm), at least its more powerful.

No.
MK 103 can't fit between cylinder banks of engines of Bf-109 (until 1945 - too late), and the FW-190 installation was found unsuccesful. That's why proposed upgraded Flak 38 in the 1st place.

(about mounting long barrel for MK 108 ):

I'm pretty sure if they could they would've done so.

They could, but there was no need since propellant (because of small content of it) couldn't use up the longer barrel.

Jumo 213 powered Fw 190s flew in 1942. The DB 603 still had serious teething problems even as late as late 1943. So it surely wasn't as perfected as you make it.

Planes powered by 603 were in use 20 months before planes powered by 213 could do the same. Enough for me.

Sorry but I don't see the logic in that. As soon as someone puts you under pressure you magically solve all problems in no time? That doesn't make any sense.

It makes perfect sense to demand a better more devoted work at projects the county depends upon.

And I also said develop, which not only means increase in power. The most important thing at the time was manufacture though, which I clearly stated.

Nope, you said:

to continue on producing and improving

And what should be a result of developing and improving of an aircraft engine, if one is not able to squeze more horse powers out of it?

.

 

[gorizont]

It's still way too heavy and the ROF is very poor. Anything below 600 rpm you can pretty much forget about unless you pack a whole lot of them into your plane and the flak 38 only has 450 rpm. Heck you might as well take the MK 103 then (440 rpm), at least its more powerful.

It's rather interesting question.
The gun and especially its ammo was designed for destroying land target (armoured cars, tanks etc), it was rather lightweighted in comparison with Mk.101, its predessor.
As far as I know Germans tried to increase its rate of fire but failed.
And for such a little bird as Bf.109 it seems too bulky and I suppose reduced markably craft's flight characteristics.

But the interesting question - why Germans could't design anythig like that: Type 5 cannon - Wikipedia, the free encyclopedia
An introduction to collecting 30 mm cannon ammunition
According to 'Japanese Aircraft Equipment 1940-45 - Schiffer' its weight was 66 kg - less than half of the Mk.103 weight.
If Japanese managed...

Gun Type 5 on its characteristics seems about the ideal motor-cannon (against aircrafts) with its weight and power - initial velocity is close to the Mg.151/20.
And its ROF is 25% higher than of Mk.103. And it was easy to unificate production of ammo as cartridge for Type 5 looks like shortened cartridge for Mk.103. I know that there are some differences in dimensions, but rather small.

 

[davebender]

Mauser MG 213 - Wikipedia, the free encyclopedia
They did. However the Mauser MG213 revolver cannon didn't make it into production before the war ended.

 

[Bug_racer]

just to add to the conversation : If you wanted to get to 40000ft fast why not develop a detachable take off rocket assisted launch ? That way you gain the altitude faster and use less fuel in the process .

 

[gorizont]

Mauser MG 213 - Wikipedia, the free encyclopedia
They did. However the Mauser MG213 revolver cannon didn't make it into production before the war ended.

30-mm MK.213C is a low velocity gun exactly as Mk.108. it's not multiporpose moreover I suppose it was not efficient against fighters (especially in dogfighting) because of low velocity.
It's good just against heavy unmaneuverable bombers/
But if you have just the only one cannon - as Bf.109K has the only motor-cannon - usefulness a low-velocity 30-mm cannon became doubtful. Especially if you pay attention at quantity of ammo for such a cannon in the box on the board.

Besides - a cannon of ballistic similar or close to ballistic of rest of armamment (MG.131) is most desirable, dispersion of shots is no more than mediocre. in the case of combination a low velocity gun + medium velocity machinguns dispersion should be quite vast and combo fire is efficient only at short distance. It is a rule for WWII fighter pilots to fire from close distances if one desired to shoot opponent with guarantee, but situations could be different.

 

[riacrato]

MG213C has a mv of 1050 m/s though. Conversion was rather easy so you could use the one or the other based on what was necessary.

 

[Shortround6]

just to add to the conversation : If you wanted to get to 40000ft fast why not develop a detachable take off rocket assisted launch ? That way you gain the altitude faster and use less fuel in the process .

Germans, among others, were experiminting with rocket assited take-off in WW II.

It worked for take-off of heaviely loaded aircraft but might be less successful for climb performance. The solid fuel rockets didn't have much burn time and liquied fueled rockets start getting expensive to use as throw aways.
An how many hundred pounds of rocket fuel do you use to save how much gasoline?

 

[davebender]

Type 791B Aircraft Cannon - Archived 2/2000
High muzzle velocity and 1,200 rounds per minute make the MG213 superior to anything else from the WWII time frame. I assume it would have entered mass production during 1946.

 

[Shortround6]

Please note that it took the French about 6 years to get the the revolver cannon into production starting where the Germans left off. I don't believe the British were much quicker and according to some accounts the American version (M 39) did see combat in 1953.
I don't know if this is becasue of the Korean War slowing things down or if the Korean War actually might have moved up priority.
I am not sure I can believe that 'Not invented here' modifications would have slowed down production of a "ready to go" gun by 4-5 years assming all three countries waited until 1948 to actually do anything with the design.

 

[Milosh]

The Germans had a rotary machinegun in WW1. If you go to the WW1 section, you can see a photo of it.

 

[drgondog]

Please note that it took the French about 6 years to get the the revolver cannon into production starting where the Germans left off. I don't believe the British were much quicker and according to some accounts the American version (M 39) did see combat in 1953.
I don't know if this is becasue of the Korean War slowing things down or if the Korean War actually might have moved up priority.
I am not sure I can believe that 'Not invented here' modifications would have slowed down production of a "ready to go" gun by 4-5 years assming all three countries waited until 1948 to actually do anything with the design.

The T-160 was a modified M-39 and was used as past of Gunval program in Korea in 1953. IIRC the a/c were modified on a special contract with NAA and tested at Eglin when I was a kid there in 1952.

It was direct result of early returning F-86 fighter pilots complaining about high altitude deficiencies of 50 cal API hitting MiGs but not causing fires at 35K and above.

 

[Civettone]

MG213C has a mv of 1050 m/s though. Conversion was rather easy so you could use the one or the other based on what was necessary.

That's for the 2 cm version. The 3 cm version had half the muzzle velocity.

The Germans couldn't make the MG 213 to work despite working on it for years and throwing a lot of money/resources at it. It is still very unclear that they would have fixed the problems by 1946.
However, that it took the allies several years to come up with their version doesn't mean that much. That happened to a lot of German innovatations.


Kris