Bf-109 vs Spitfire vs Fw-190 vs P-51

[Juha]

I'd say that Spit Mk XIV was clearly superior over 190D-9 above 6000m but lower down they were more equally matched, there D-9 tended to be slightly faster but XIV climbed better. And D-9 rolled better, which was more important than that XIV turned better. I'm not sure how familiar Closterman was to XIV and anyway D-9 looked clearly better in his books than in his war-time combat reports and sqn ORBs.

Juha

 

[tomo pauk]

The Fw 190 with in Line V12s, had the potentional to be more than equal for the allied fighters. However because of the war conditions several compromises were made that crippled the final result that went in production, as D-9. The compromises were

1) request to use B4 fuel, i remind that the Fw190A used C3 for almost all its career
2) quality of Construction (due to lack of skilled technicians, lack of Materials eg rubber to seal the engine gap, demand for gast production)
3) demand for very,very easy production. This resulted in design choises that added weight. eg the demand to deliver the engine as a complete power egg added weight, which in turned requested the extention of the rear fuselage which again increased weight
4)use of engines initially intended for bombers. Thus instead of a Motor cannon had druggy nose mgs with their heavy synchronization gear
5) lack of 2 stage superchargers, delayed beyond any hope again for production purposes
6)in order not to disturb production the same wing was retained. So the result was very High wing loading . By the time they decided that enough was enough and introduced new wings for the 190 family was far too late. For the same reson other improvements were not made eg fully retractable tail Wheel, lighter 20 mm guns etc
7) request for heavy armor and sophisticated radio equipment. Things nice to have but in combination with the weak engine the performance suffered

Because of the above reasons , i would agree with Tomo Pauk ,that the average D9 was generaly inferior to the 1945 anglosaxon fighters.
However when a D13 flew against a tempest post war proved decently competitive

All good points. The timely introduction of 2-stage superchargers was maybe the greatest thing LW fighters lacked in 1944 (apart from plenty fuel and trained pilots).
Non-introduction of the DB 603A in the Fw-190 airframe might also be counted as a major mistake. A decent force of, we can call them 'Fw-190C's, was well within scope of the German war industry for the late 1943 (when the DB 603A is more or less debugged). The DB 603 (vs. the 'stock' BMW 801D) was offering less drag, greater power exhaust thrust at high altitudes, decreased consumption, better intake scoop (= better power at hi-alt), but I'm sure people know that already. Fuel was B4, another plus. Can use MW 50 system.
It also allowed for motor-cannon, so one can have a very useful bomber destroyer with MK 108 installed. The MK 108 as motor-cannon was indeed less draggy affair than twin MG 131s under cowling, when comparing drag data for the D-9 vs. D-12 or Ta-152H.

With that said, a major shortcoming of the D-9 was timing. Too late to matter, even jets were earlier in the combat.

 

[Shortround6]

The two stage superchargers are not magic. You need either good fuel, good inter-coolers or LOTS of MW50/water injection (or 2 out of 3) to get them to work.
P-38s were limited in power in the 20,000ft range even with 100/130 fuel due to poor intercoolers until the J model. Even the D and E were having problems trying to make 1150hp. The Turbo would deliver the pressure but the intake temperature was too high after the small inter-cooler. At 25,000ft you have to compress the air about 2.7 times just to reach sea level pressure. This raises the temperature of the intake air by hundreds of degrees.

Now you have to balance that against what the Germans wanted which was to get away from having to use C3 fuel. Initial planning being 1 to 2 years away from start of combat. A new refining process might have given them much more C3 fuel or some other factor might have changed things but it was NOT the smart way to bet.

 

[dedalos]

t

All good points. The timely introduction of 2-stage superchargers was maybe the greatest thing LW fighters lacked in 1944 (apart from plenty fuel and trained pilots).
Non-introduction of the DB 603A in the Fw-190 airframe might also be counted as a major mistake. A decent force of, we can call them 'Fw-190C's, was well within scope of the German war industry for the late 1943 (when the DB 603A is more or less debugged). The DB 603 (vs. the 'stock' BMW 801D) was offering less drag, greater power exhaust thrust at high altitudes, decreased consumption, better intake scoop (= better power at hi-alt), but I'm sure people know that already. Fuel was B4, another plus. Can use MW 50 system.
It also allowed for motor-cannon, so one can have a very useful bomber destroyer with MK 108 installed. The MK 108 as motor-cannon was indeed less draggy affair than twin MG 131s under cowling, when comparing drag data for the D-9 vs. D-12 or Ta-152H.

With that said, a major shortcoming of the D-9 was timing. Too late to matter, even jets were earlier in the combat.

I fully agree with this post.

This aircraft should be the next step after the A series. The Fw190c . A DB 603 engine installed to the standart 190 airframe. No extentions, nothing. With 3 20 mm guns could have a normal take off weight of 4000kgr or even less. Prototypes V13 and V15 flew very well in this configuration. And could be in service by late 1943
It s beyond Logic that RLM rejected this proposal, and used the limited DB 603 numbers for the ... Me 410!

 

[Denniss]

A Fw 190C without pressurized cockpit and turbocharger may have worked but it had one problem - the DB 603. Even by 1943 it had reliability problems and production was by far too low for a high volume production aircraft.

 

[tomo pauk]

Indeed, the reliability problems surfaced during 1943; mostly, if not all cured by later that year?
The Me 410 production used ~2400 engines (plus spares), that would be much more than whole V-12 powered Fw-190 derivatives used up.

The two stage superchargers are not magic. You need either good fuel, good inter-coolers or LOTS of MW50/water injection (or 2 out of 3) to get them to work.
P-38s were limited in power in the 20,000ft range even with 100/130 fuel due to poor intercoolers until the J model. Even the D and E were having problems trying to make 1150hp. The Turbo would deliver the pressure but the intake temperature was too high after the small inter-cooler. At 25,000ft you have to compress the air about 2.7 times just to reach sea level pressure. This raises the temperature of the intake air by hundreds of degrees.

Now you have to balance that against what the Germans wanted which was to get away from having to use C3 fuel. Initial planning being 1 to 2 years away from start of combat. A new refining process might have given them much more C3 fuel or some other factor might have changed things but it was NOT the smart way to bet.

All good points.
We can recall that DB 628, one of 1st DB 2-stage engines, used intercooler (air-to-air), that was located under engine, being fed with compressed air from engine-stage compressor. Between 1st stage and engine-stage there was no intercooler.
The DB 605L was using C3 fuel, the MW 50 was used both for Notleistung (2800 rpm, 1.75 ata = 1350 PS at 9.6 km) and Kampfleistung (2600 rpm, 1.43 ata = 1150 PS at 9.6 km); consumption 150 L/h and 75 L/H of MW 50 mixture respectively.

 

[spicmart]

Why would a power egg weigh more?
What would approximately be the weight of such a synchronization gear?
The high wing loading seemed common with german aircraft the whole war through if one sees the wing dimensions compared to their allied counterparts being smaller while having comparable weight. This includes new/drawing board designs. If the wing loading would have been such a problem then the much heavier Ta 152C should have gotten a much larger wing than it actually got. Its wing area was just 1,2 square meters larger than the D-9's while almost being a ton heavier.
The D-13 did not have much more performance than the D-9 at low/medium altitudes iirc. I have some charts where one can see it but most the books are stored elsewhere as I just moved.
Some sources say that it trounced the Tempest in that mock combat though.
There were 1945 Doras that had enough power. Maybe those were the exception.

 

[spicmart]

With a power egg an annular/drum radiator is attached in front of an engine. According to a british test this kind of installation has less drag than other types, including leading edge radiators. Only the Mustangs cooling system is more effective in terms of thrust/drag.
Albeit the german ones had hinged gills and not sliding gills with the former getting a drag increase as the gills open.
The "Junkers radiator nose" should reduce this when replacing the normal radiator of the Doras that were not sufficient.

C&P:

davebender: Also makes the aircraft more damage resistant. Engine block protects radiator from rear shots and coolant lines are very short. Hits in wing or fuselage (except engine compartment) will not cause a coolant leak.

razor1uk: Also with the annular rad' cooled power egg, less coolant pipework and hence coolant; lowering the 'wet' installed 'ready to use' weight further than those installations that didn't have nose mounted cooling.

 

[wuzak]

With a power egg an annular/drum radiator is attached in front of an engine. According to a british test this kind of installation has less drag than other types, including leading edge radiators. Only the Mustangs cooling system is more effective in terms of thrust/drag.
Albeit the german ones had hinged gills and not sliding gills with the former getting a drag increase as the gills open.
The "Junkers radiator nose" should reduce this when replacing the normal radiator of the Doras that were not sufficient.

The British tests you speak of may be the ones carroed out by Napiers. Their annular radiator was quite different to the ones used by the Germans.

The German ones basically had the radiator wrapped around the prop shaft, but otherwise in the same orientation to the direction of flight of most radiators. Air flow was controlled by cowl flaps, like in radials.

The Napier system was different.

It also used a cowl ring to control air flow, similar to what the BMW 801 had in some versions.

 

[wuzak]

Having said that, the Tempest I with the leading edge radiators was as fast as the Tempest VI fitted with the annular radiator, despit being several years earlier and probably having less power.

 

[tomo pauk]

The power egg, as the DB 603 was in offering, was probably the best way for the Fw-190 to 'go inline'. As spicmart noted, the weight of coolant system and it's vulnerability are cut to the smallest amount.

 

[spicmart]

The British tests you speak of may be the ones carroed out by Napiers. Their annular radiator was quite different to the ones used by the Germans.

The German ones basically had the radiator wrapped around the prop shaft, but otherwise in the same orientation to the direction of flight of most radiators. Air flow was controlled by cowl flaps, like in radials.

The Napier system was different.

It also used a cowl ring to control air flow, similar to what the BMW 801 had in some versions.

The normal/early radiator were annular. The later ones were of drum shape. Apparently those were more effective (more cooling area?). It also had less drag. The Napier's looks like a drum type. I guess the cowl ring is the sliding gills?