Optimize the FW190 for the Eastern Front

[wiking85]

Most Fw190s served against the Western Air Forces and new models were optimized for threats in the west that weighed down the fighters that ended up serving in the East. Heavier armor and armament for bomber killing affected all German fighters from 1942 on, but how could the Fw190 have been optimized to fight in the East against the new La-5s and -7s for combat under 20k feet?
Focke-Wulf Fw 190 - Wikipedia, the free encyclopedia

 

[tomo pauk]

Up-rate the engines ASAP, via increased boost. Works fine under 6 km.
Remove the fuselage MGs, retain 4 canons (hopefully all 4 MG 151/20E) since there are plenty of Il-2 and Pe-2 around, plus LL A-20s and B-25s. A more streamlined belly rack will also be good, for less of the speed loss.

 

[wiking85]

Up-rate the engines ASAP, via increased boost. Works fine under 6 km.
Remove the fuselage MGs, retain 4 canons (hopefully all 4 MG 151/20E) since there are plenty of Il-2 and Pe-2 around, plus LL A-20s and B-25s. A more streamlined belly rack will also be good, for less of the speed loss.

Were they historically able to boost the BMW engine earlier than the did historically? If so why did they hold back?

 

[tomo pauk]

The BMW 801D was fully rated (2700 rpm, 1.42 ata) by October 1942. About in the same time the Fw-190 was introduced in the Eastern Front, and was certainly better than the La-5, or anything the Soviets were able to throw in. The La-5F evened that a bit in second half of 1943.
Fw-190s used overbosting via C3 injection by that time, tough the system seem to be limited for Jabo versions only, and only for 1st supercharger gear. So a more prolific use of that system will benefit all of the Fw-190s, also using it in 2nd S/C gear. The 'plain' overboosting was tested in second half of 1943 (~ 1st Sept 1943), so usage before 1944 was probably out of question. The C3 injection involves smaller rise of cylinder temperatures, the 'plain' overboosting is simpler and uses less fuel.

 

[wiking85]

The BMW 801D was fully rated (2700 rpm, 1.42 ata) by October 1942. About in the same time the Fw-190 was introduced in the Eastern Front, and was certainly better than the La-5, or anything the Soviets were able to throw in. The La-5F evened that a bit in second half of 1943.
Fw-190s used overbosting via C3 injection by that time, tough the system seem to be limited for Jabo versions only, and only for 1st supercharger gear. So a more prolific use of that system will benefit all of the Fw-190s, also using it in 2nd S/C gear. The 'plain' overboosting was tested in second half of 1943 (~ 1st Sept 1943), so usage before 1944 was probably out of question. The C3 injection involves smaller rise of cylinder temperatures, the 'plain' overboosting is simpler and uses less fuel.

What is C3 injection and how is it different than normal boost?

 

[wiking85]

Also this says C3 injection wasn't ready until mid-1943:
FW 190 A-5 Performance

 

[tomo pauk]

That is reasonably timely, considering that 801D was fully rated for some 8 months before that.

What is C3 injection and how is it different than normal boost?

It employs a separate system (pump, tubes, nozzles) that 'normal' over-boosting does not use. The C3 injection is a form of ADI (anti-detonant injection), where the extra fuel is not burned in cylinders, but it cools the charge, so more boost can be applied. Eventually the conclusion was that 'normal' over-boosting was about as useful, and engines were capable to handle greater temperatures.
Both systems were good for up to about 1.58-1.65 ata, vs. usual 1.42 ata. That meant 1900-2000 PS in low gear, and up to 1650 PS in high gear (not sure the C3 injection system was ever tested/allowed for high S/C gear)

 

[wiking85]

So if the C3 system is not around until mid-1943 and only then on a limited basis (I'm guessing the extra complications and cost won't make it scalable) we are then only left with the removal of the fuselage guns; why them though? They were supposed to be the most accurate. Why not take off one set of cannons on the wings instead? They were heavier and the lower ammo ones (the outside ones had only 140 RPG instead of the 250 for the inner ones) could be dropped instead with greater weight savings, thus keeping the more accurate, lighter fuselage mounted guns. Were those more drag inducing?

 

[tomo pauk]

The 4 cannon set-up has about twice the firepower vs. the 2 cannons and 2 LMGs. The fuselage MGs might be accurate, they don't mean anything for killing an Il-2 or any of decent twin the VVS was operating.

 

[wiking85]

The 4 cannon set-up has about twice the firepower vs. the 2 cannons and 2 LMGs. The fuselage MGs might be accurate, they don't mean anything for killing an Il-2 or any of decent twin the VVS was operating.

It does matter to fighting Soviet fighters. In terms of MGs they were MG131s, which were .51 caliber bullets that the Sturmovik was certainly not immune to, nor were Soviet twin engines.
Erich Hartmann made a carrier of downing Sturmoviks in his Bf109 whose heaviest weapon was the MG151. Having two cannons and large caliber MGs would have been even more effective than a single MG151 (or 20mm Motorkanone) and two MG17s.
Erich Hartmann - Wikipedia, the free encyclopedia

 

[tomo pauk]

The MG 131 installation involves adding the drag, that will be as great as 2 extra cannons? Part of the reason the Fw 190A-8 was 6-10 km/h slower than the 190A-6/A-5. And it still has maybe 60% of firepower than a 4-cannon Fw-190.

Erich Hartmann made a carrier of downing Sturmoviks in his Bf109 whose heaviest weapon was the MG151

Problem was that there was maybe 1% of German (or other country's) pilots that were as good pilots/marksmen as Bubbi was. The run-on-the-mill pilot needed plenty of firepower vs. the target Hartmann will kill with a single cannon.
We can recall that Germans were not shy to use the gondola cannons on the Bf 109, despite the known performance maneuverability loss induced.

 

[wiking85]

The MG 131 installation involves adding the drag, that will be as great as 2 extra cannons? Part of the reason the Fw 190A-8 was 6-10 km/h slower than the 190A-6/A-5. And it still has maybe 60% of firepower than a 4-cannon Fw-190.

I'm not clear on what you're saying here. What was the reason the A-8 was slower? I thought it was the extra armor, addition of the 30mm cannons, a larger fuel tank, and more powerful, heavier engine. Not sure if the new canopy changed the aerodynamics.
List of Focke-Wulf Fw 190 variants - Wikipedia, the free encyclopedia

Problem was that there was maybe 1% of German (or other country's) pilots that were as good pilots/marksmen as Bubbi was. The run-on-the-mill pilot needed plenty of firepower vs. the target Hartmann will kill with a single cannon.
We can recall that Germans were not shy to use the gondola cannons on the Bf 109, despite the known performance maneuverability loss induced.

Bubi was only as good as he was due to getting close where he did not need to be a marksman and he was coached on that by more senior pilots, so it was not unique to him. In fact I've seen FW190 handbooks that recommend the same. Correct me if I am wrong, but the gondola guns were only used against Western heavy bombers (the viermots) and not on the Eastern Front. Bubi was only using standard gun layouts in the East, sans gondolas. The only reason other pilots needed the extra guns was due to opening up too far away and wasting a lot of ammo trying for long range kills; basically using 'spray and pray' tactics.

 

[davebender]

Design Fw-190 for DB603 engine from 1937 onward with annular radiator. Hence wing will be further forward, eliminating need for fuselage extension on historical Fw-190D. This results in a lighter and more compact aircraft.

Armed with 3 x 20mm cannon. One in hub plus two inboard wing positions. Outer wing weapon positions can be omitted from the design. Cowl machineguns can be omitted too. Instead hub cannon gets twice as much ammo as wing cannon since it's inherently more accurate.

Resulting aircraft should perform a bit better then historical Fw-190D9 and should be in mass production at least as early as historical Fw-190A. Engine won't require C3 fuel as historical Fw-190A did and you avoid technical problems of BMW801 engine overheating.

 

[tomo pauk]

I'm not clear on what you're saying here. What was the reason the A-8 was slower? I thought it was the extra armor, addition of the 30mm cannons, a larger fuel tank, and more powerful, heavier engine. Not sure if the new canopy changed the aerodynamics.
List of Focke-Wulf Fw 190 variants - Wikipedia, the free encyclopedia

The A-8 have had the same engine as, for example, an A-4 - BMW 801D. It was allowed for over-boost, however. 30mm cannons were not a standard on the A-8, nor it was a heavier armor suite. The extra fuel tank will cost some speed, indeed. Here is how much the MG 131 vs. MG 17 cost in speed (source):

From this loss is about 3 mph (5 km/h) from the two additional MG 151 runs and ~ 6 mph (10 km/h) due to the changes for the installation of the MG 131 cover front windscreen (see Flight Report Fw 190/861 with 2 MG 17 + 4 MG 151).

Bubi was only as good as he was due to getting close where he did not need to be a marksman and he was coached on that by more senior pilots, so it was not unique to him.

Hence I've mentioned 'pilot/marksman' - you need to have at least one of the two if you want a single cannon to suffice. Not granted for any airforce of ww2.

In fact I've seen FW190 handbooks that recommend the same.

Could you please point me to the excerpts?

Correct me if I am wrong, but the gondola guns were only used against Western heavy bombers (the viermots) and not on the Eastern Front. Bubi was only using standard gun layouts in the East, sans gondolas. The only reason other pilots needed the extra guns was due to opening up too far away and wasting a lot of ammo trying for long range kills; basically using 'spray and pray' tactics.

The Soviets have tested the captured Bf-109G2 with gondolas, and same 109s were used on the MTO. LW certainly judged the Bf-109 to be under-armed as-is, hence such boost in the firepower even if it involves speed, RoC and roll penalties.

 

[wiking85]

The A-8 have had the same engine as, for example, an A-4 - BMW 801D. It was allowed for over-boost, however. 30mm cannons were not a standard on the A-8, nor it was a heavier armor suite. The extra fuel tank will cost some speed, indeed. Here is how much the MG 131 vs. MG 17 cost in speed (source):

From this loss is about 3 mph (5 km/h) from the two additional MG 151 runs and ~ 6 mph (10 km/h) due to the changes for the installation of the MG 131 cover front windscreen (see Flight Report Fw 190/861 with 2 MG 17 + 4 MG 151).

Then the argument is what is more valuable, the higher velocity Mg131 with greater accuracy due to mounting and speed, or the hitting power and greater speed of the 2 additional cannons in wing mount?

The Mg151/20 was 700mps velocity, the Mg131 was 750mps.

Hence I've mentioned 'pilot/marksman' - you need to have at least one of the two if you want a single cannon to suffice. Not granted for any airforce of ww2.

I'm not saying a single would be enough, rather that a pair of MG151/20s in the wing roots and a pair of MG131s in the fuselage would suffice, especially if they closed in enough (IIRC within 300m for best effect).

Could you please point me to the excerpts?

They were in here:
La-5/7 vs Fw 190: Eastern Front 1942-45 (Duel): Dmitriy khazanov, Jim Laurier, Gareth Hector: 9781849084734: Amazon.com: Books

The Soviets have tested the captured Bf-109G2 with gondolas, and same 109s were used on the MTO. LW certainly judged the Bf-109 to be under-armed as-is, hence such boost in the firepower even if it involves speed, RoC and roll penalties.

Any idea how common they were in the East? Also when did they get ahold of them? They tested a Me410 too, but AFAIK those weren't used in the East either, but were captured at the end of the war.

 

[dedalos]

I would take a more aggressive approach for a Eastern front Air superiority specialized FW190A

1)Normal take off weight 3800kgr. That means A-5 airframe, No MGs ,just 2 20mm guns with 250 rpg. More than enough for the Eastern front. Also no fancy radios. No bomb rack for the majority of the missions

2) Wing tanks in place of the external 20mm guns, used only when neseccary

3) Fully covered main wheels and fully retractble tail wheel

4)1.65 boost as soon as possible, wide blade propellers as soon as possible

The above are historical very possible
I would also propose fowler type combat flaps but as far as i know the german did not ever developed such devices

The ultimate performing Fw would be all the above in combination with Db603 with C3,( no extentions,standart A5 fuselage)

 

[tomo pauk]

Then the argument is what is more valuable, the higher velocity Mg131 with greater accuracy due to mounting and speed, or the hitting power and greater speed of the 2 additional cannons in wing mount?
The Mg151/20 was 700mps velocity, the Mg131 was 750mps.

The Mine shell was fired at 805 m/s, so the MG 151/20 takes the lead in MV, too. The MG 131 fired faster, though, 900-930 rpg (minus the cost of being synchronised - 10-15%?), the MG 151/20 was at 630 rpg (Mine shell) to 695 (HE-I shell). All in all, I'd go with 4 cannons rather than with 2 + 2.

I'm not saying a single would be enough, rather that a pair of MG151/20s in the wing roots and a pair of MG131s in the fuselage would suffice, especially if they closed in enough (IIRC within 300m for best effect).

Enough indeed to kill a fighter. The VVS fielded other, more sturdier types too, and 4 cannons are a better bet there.

They were in here:
La-5/7 vs Fw 190: Eastern Front 1942-45 (Duel): Dmitriy khazanov, Jim Laurier, Gareth Hector: 9781849084734: Amazon.com: Books

Thanks for the link. I was hoping that you'd point me to real manuals

Any idea how common they were in the East? Also when did they get ahold of them? They tested a Me410 too, but AFAIK those weren't used in the East either, but were captured at the end of the war.

I don't know how much the gondolas were used there. The G-2 with gondolas was tested mid war, the report can be found at Kurfurst.

 

[tomo pauk]

...
I would also propose fowler type combat flaps but as far as i know the german did not ever developed such devices

Japanese have had the so called 'butterfly flaps' used from the 1st Ki-43s on, so a little feedback could come in handy?

The ultimate performing Fw would be all the above in combination with Db603 with C3,( no extentions,standart A5 fuselage)

With C3 it would be circa 2000 PS; the B4 + MW 50 also makes sense here. I'd go for 3 cannons, one of them 30mm once available. The type would be much more needed in the West, however.

 

[Totalize]

I believe the 190 had fairly high wing loading. for dog fighting under 20K feet I would remove the MG/FF's or later the MG151/20's from the outer wings to ease the wing load. Definitely keep the fuselage guns.

 

[wiking85]

I believe the 190 had fairly high wing loading. for dog fighting under 20K feet I would remove the MG/FF's or later the MG151/20's from the outer wings to ease the wing load. Definitely keep the fuselage guns.

Actually yeah, its 49lbs/square foot wing loading is about 10 lbs higher than any fighter I can find.