Effect of operational Fw187s during the Battle of Britain

[davebender]

First flight and all subsequent flights should have been with DB601 engines. Then the single seat Fw-187 could enter mass production before the end of 1939.

 

[davebender]

Me-110s flew close escort after Me-109s departed, low on fuel.

The reason for close escort was lack of numbers to control more airspace. Which brings us to the crux of the problem. RAF was flying twice as many fighter sorties over England as Luftwaffe. After Me-109s leave RAF advantage is much greater.

Zerstorer Gruppe by Ludwig von Eimannsberger thoroughly documents numbers and tactics employed for V./(Z)LG1 missions during 1939 and 1940.

 

[jim]

Hmmm,


tactical use
In BoB, Fw-187 replacing Bf-110 would be primarely assigned to close escort for bombers. Remember, we are changing A/C, not tactics. Used in this capacity, the airplane would be tied to slow bombers, exposing it´s rather poor low speed handling, large target size, poor initial acceleration and low speed roll rate. This is approximately the same tactical limitation which assured the complete failure of the Bf-110. Instead of doing high cover at it´s high cruise speed, exhibiting zoom-climbs, superior dive capabilities and playing the strength of it´s stable weapon platform with concentrated heavy armement, the Fw-187 finds itselfe in no better position than the Bf-110, arguably even in a worse one because the Bf-110 has a rear gunner to at least cover some blind arcs and give opportunity of warning from beeing jumped.
Thus, in my opinion, the presence / absence of the Fw-187 has no effect unless the tactics are drastically changed. It´s not the best plane for dogfighting a single engined A/C like the Hurricane and Spitfire, either. Keep in mind, a twin engined fighter A/C has to be limited in agility compared to a single engined one.
The solution to BoB is not another, more expansive twin engined fighter but

[A] rejection of close escort tactics
a larger number Bf-109, equipped with drop tanks to increase range and endurance

Mr Delcyros
I totaly agree that different tactics for the 110 and drop tanks for the 109 would make big diference and are the most important factor
But where you base your claim that the Fw187 would have inferior accelaration and low speed handling? Its power loading with DB601A would be the best of its time , and its 30m2 wing surface provided it with low wing loading
Even its roll rate was near that of the Bf109B during tests
Why such an airplane would not be able to dogfight the british fighters? With clear speed ,roc, dive advantages would be exceptional on the vertical manouvers. The numbers indicate that it may even have superiority in sustained turn rate especially if 601N are used or the british fighters dont use 100 octane fuel ( which anyway is available for 5 minutes)

De Havilland Hornet and very late P38s have proved that if the numbers are correct, twin engines fighters can mix it with single seaters

 

[wuzak]

Fw 187 had twice the weight of a Spitfire I, but only 35% more wing area.

It's going to turn with a Spitfire?

It had twice the power, so a similar power to weight as the Spitfire.

The wing mounted engines will slow the rate of roll compared to a single engined aircraft.

So speed and climb would appear to be the main advantages of the type over the Spitfire in 1940. That and negative G capability thanks to FI (assuming Db 601s and not Db 600s or Jumo 210s).

Spitfire's max performance may have been only for 5 minutes - but how long would it be for the Fw 187 in 1940? 1 minute? 5 minutes?

 

[Shortround6]

What weight is being used for this Fw 187???

Take the A version (two seat) and add about 1000lbs (Bf 109E-1 is about 500lbs heaver than a Jumo powered Bf 109), If this thing is replacing the Me 110 then it is a two seater. Not that leaving out the rear seat guy really buys much.

Please remember that the Fw 187 V1 V2 single seaters had an armament of TWO Mg 17s.

Early Me 110s carried the exact same radio as a He 111. The Standard Luftwaffe radio for single seaters in the late 30s being rather short ranged (so was everybodies).

It is also rather useless in original form as a night fighter. Cockpit is so cramped that 6 engine instruments (for each engine) are mounted outside the cockpit on the engine cowl just a few inches above the exhaust stubs. Yes you could fit it with exhaust shrouds so you had some hope of seeing the instruments at night.

and a picture of the cockpit.

 

[tomo pauk]

5 minutes was the 'Kurzleistung', eg. ~1020 PS at 4-4,5 km.

I can agree with proponents of Fw-187 with DB-601s - it would be a tough player during BoB, with better speed, agility climb than Bf-110, but also with better range capabilities than Bf-110. Sorta no-nonsense P-38. In order for such a plane to really achieve something, it also needs to be employed in proper way - Freijagd, not saddling it with close escort*, and replacing it's pair of cannons with 2 pairs of MG-17s (better duration of fire).

With Fw-187 unsuitable for night fighter job, LW still has 2 airframes capable to undertake the mission, so no loss there.

* the P-51s were started hughe attrition of Luftwaffe once they were alowed to roam free, consequence being ever smaller bomber losses,

 

[Glider]

I do admit that its a nice looking aircraft but a little tight, its a bit like a gliders cockpit. Adding the larger engines must have played merry hell with the Cog there so far forward

 

[delcyros]

Mr Delcyros

But where you base your claim that the Fw187 would have inferior accelaration and low speed handling? Its power loading with DB601A would be the best of its time , and its 30m2 wing surface provided it with low wing loading
Even its roll rate was near that of the Bf109B during tests
Why such an airplane would not be able to dogfight the british fighters? With clear speed ,roc, dive advantages would be exceptional on the vertical manouvers. The numbers indicate that it may even have superiority in sustained turn rate especially if 601N are used or the british fighters dont use 100 octane fuel ( which anyway is available for 5 minutes)

Initially, engines need to spin up to apply full power. While a Db-601A/B is fast in this, it´s still not an instant event and a slight delay has to be reckoned with. The pilot has to adjust the mixture setting, boost and possibly optimize propellor pitch, too (no Kommandogerät yet), since we have two engines instead of one, engine management takes slightly longer than in a single engined A/C. Fast, but not unnoticably in case of beeing jumped in close escort.
A Db-601A/B driven -187 has some negative aspects, one beeing much heavier than the -210 driven variant. The installation weight of the Jumo-210 was 525 kg (=1050 kg for the -187A) while the Db601N weights in 780kg each (=1560kg for the Db601 Fw-187). Add in structural strengthenings of the main frame, the landing gear, a heavier prop, more coolant liquid and a larger radiator and the empty weight of the Fw-187 should raise from 3,700kg empty to >4,300kg empty. Some more additions I can think of compared to the principal empty weight:

[1] 167kg for armour plate and bullet proof glass (as with Bf-110c)
[2] 225kg for 300 rounds each MG17 + 60 rounds each 20mm gun
[3] 64kg engine oil (same as Bf-110)
[4] 200kg for 2 crew
[5] 964 kg fuel (same as Bf-110)

Thus, I can´t really see, how the take off weight of the Fw-187 can end up much lighter than 6t. That´s 2.4 kg per hp at the very best. Remember, Powerload isn´t determining acceleration, it´s powerweight. While the -187 may be better than th -110 in this regard (=2.6), it´s still worse than a Bf-109e (=2.16) and thus presents no advantage in acceleration over this A/C.
Another problem with that number is the Focke Wulf wing design, which had a simple and thin wing (good for high speed) but a lack of high lift devices, resulting in a rather low Clmax of 1.52. With that coefficient, minimal flying speed should be quite high, around 152 km/h for G(f) = 5950kg (normal take off weight) and 30m^2 wing area as compared to 132km/h at 6530kg normal take off weight for the Bf-110C2. Thus, a higher landing speed has to be reckoned with, correspondingly a larger stall speed at any altitude too, and these airplanes cannot as easily negotiate shorter runways as could the -109 and -110.

I am not to enthusiastic about the charmant looking Fw-187. This airplane bought speed by reducing the size of fuselage and wing, and by adopting a high speed airfoil, not by more advanced aerodynamic concepts of airframe integration. The same trick-in principle- can be done with the Bf-110c. Originally the top speed raised from 328mph to 345 mph with the change from Db601A to Db-601N. It´s 38.2m^2 wing area reduced to 31 to 32m^2 should give similar ~150 km/h min. speed but top speed in the region of ~360mph with Db601A and ~378mph with Db601N, slightly slower than the Fw-187, but not by much.

 

[stona]

Noone has mentioned the vulnerability of an aircraft with a 245 litre capacity fuel tank in each wing in a dogfight yet

They would be an ideal target for Major Dixon's .303 B. Mk VI 'De Wilde' bullets,and 8 Brownings can fire a lot of them.

I do have reservations with the proposed time frame in which several hundred Daimler Benz powered Fw 187s could have been in service for the BoB. As far as I'm aware none of the Fw 187 prototypes was fitted with the DB 601 before the outbreak of the war. V5 had a projected completion time (with DB 601s) of July 1939 but this doesn't seem to have been achieved. There is in any case no way you can have several hundred production aircraft in service one year later,even had the RLM not pulled the plug.
When the four A-0s got to 6.werksschutzstaffel in early 1940 there were plenty of problems to iron out and these aircraft had the original engine installation.

The Fw 187 was potentially a very good aeroplane,but extrapolating theoretical performance into a campaign winning machine,assuming there had been plenty available,is a far from safe bet.

Cheers

Steve

 

[jim]

Initially, engines need to spin up to apply full power. While a Db-601A/B is fast in this, it´s still not an instant event and a slight delay has to be reckoned with. The pilot has to adjust the mixture setting, boost and possibly optimize propellor pitch, too (no Kommandogerät yet), since we have two engines instead of one, engine management takes slightly longer than in a single engined A/C. Fast, but not unnoticably in case of beeing jumped in close escort.
A Db-601A/B driven -187 has some negative aspects, one beeing much heavier than the -210 driven variant. The installation weight of the Jumo-210 was 525 kg (=1050 kg for the -187A) while the Db601N weights in 780kg each (=1560kg for the Db601 Fw-187). Add in structural strengthenings of the main frame, the landing gear, a heavier prop, more coolant liquid and a larger radiator and the empty weight of the Fw-187 should raise from 3,700kg empty to >4,300kg empty. Some more additions I can think of compared to the principal empty weight:

[1] 167kg for armour plate and bullet proof glass (as with Bf-110c)
[2] 225kg for 300 rounds each MG17 + 60 rounds each 20mm gun
[3] 64kg engine oil (same as Bf-110)
[4] 200kg for 2 crew
[5] 964 kg fuel (same as Bf-110)

Thus, I can´t really see, how the take off weight of the Fw-187 can end up much lighter than 6t. That´s 2.4 kg per hp at the very best. Remember, Powerload isn´t determining acceleration, it´s powerweight. While the -187 may be better than th -110 in this regard (=2.6), it´s still worse than a Bf-109e (=2.16) and thus presents no advantage in acceleration over this A/C.
Another problem with that number is the Focke Wulf wing design, which had a simple and thin wing (good for high speed) but a lack of high lift devices, resulting in a rather low Clmax of 1.52. With that coefficient, minimal flying speed should be quite high, around 152 km/h for G(f) = 5950kg (normal take off weight) and 30m^2 wing area as compared to 132km/h at 6530kg normal take off weight for the Bf-110C2. Thus, a higher landing speed has to be reckoned with, correspondingly a larger stall speed at any altitude too, and these airplanes cannot as easily negotiate shorter runways as could the -109 and -110.

I am not to enthusiastic about the charmant looking Fw-187. This airplane bought speed by reducing the size of fuselage and wing, and by adopting a high speed airfoil, not by more advanced aerodynamic concepts of airframe integration. The same trick-in principle- can be done with the Bf-110c. Originally the top speed raised from 328mph to 345 mph with the change from Db601A to Db-601N. It´s 38.2m^2 wing area reduced to 31 to 32m^2 should give similar ~150 km/h min. speed but top speed in the region of ~360mph with Db601A and ~378mph with Db601N, slightly slower than the Fw-187, but not by much.

Mr Delcyros
I have a lot of respect for your opinion. But i slightly disagree on this subject
For the 2-seat DB601 Fw 187 i read projected weights of 4200kgr empty ,5500 full load. Fw 187 was designed from the start for DB 600 series engines , so no extra strengthening was nessecary
But the version i suggest that could make some difference would be the Single seat. All my previus comments were refering to a single seat version that would be about 500kgr lighter. So i guess we have different conclusions because we accept different weights
I do agree that even the 187 would be in disadvantage if was used as the Bf 110 c, flying along the bombers
I dont agree with your comment about trading fuselage and wing sizes for speed. Any 2 engine fighters with decent performance had relatively small fuselages. Hornet ,P38, Ki 83, Do 335. Even Bearcat , in comparison to F6F, sacrificed wing and fuselage sizes (and structure strength?)
It s wing was 30m2 . Why you consider it small? The heavier p38 had also 30,43m2 and the much heavier Hornet 33,54m2
Whats wrong with high speed airfoils? Especially if you keep weight low.After all speed was the desicive factor, especially for an escort fighter. (And P51 with its laminar flow wing, according to our American friends , had no problem out dog fighting anything)
Besides future version would have improved wings
"advanced aerodynamic concepts of airframe integration. "
If i understand correctly what you mean with your above phrase, the only aircraft in this category would be Do 335 and J7W. And maybe P38
Even the superb Hornet and Ki 83 were not result of some exotic solution but careful and detail desigh, streamlining and weight saving. Or the Tigercat. What advanced aerodynamic concepts it offerd?

 

[stona]

The P-51 had a laminar flow wing only in theory. Both US and British aerodynamicists doubted this in real flight conditions and a very long and thorough German investigation concluded that.

"These measurements clearly revealed the fact that the laminar flow effect completely disappeared at real flight Reynold Numbers."

And

"the performance of the Mustang could not be attributed to its laminar flow airfoil. It was the overall low drag design of this aircraft with clean surfaces including the careful design of the radiator that was the key of its good performance."

Cheers

Steve

 

[Glider]

I am just trying to clarify my understanding of the weights.

Jim - You are working on an empty weight of 3,700kg empty and presumably 5,000kg full load.
However the breakdown of the weights listed by Delcryos seem right and total 1,420kg, plus I suggest more for self sealing fuel tanks call it 1,500kg

So the question is, what do you leave out to lose the extra 200 kg?


[1] 167kg for armour plate and bullet proof glass (as with Bf-110c)
[2] 225kg for 300 rounds each MG17 + 60 rounds each 20mm gun
[3] 64kg engine oil (same as Bf-110)
[4] 964 kg fuel (same as Bf-110)

edit - I wouldn't say that the Do 335 had a small fuselage, it was huge.

 

[stona]

Soooo,it seems that Focke-Wulf were keen to use an evaporative cooling system in conjunction with the DB 601 A on their Fw 187.

Focke-Wulf and Daimler Benz cooperated on developing such a system with the second DB 601 A prototype. Testing,not in an airframe but on stands,was completed in July 1939. The first test run of the system in a Fw 187 was on the port engine of V5 on 15th September 1939. You'll notice that at least as far as the British and French are concerned WW2 has already started and the airframe/engine combination has not yet flown.

The testing of the DB 601 engines (V40 and V 42) continued into 1941,there were plenty of problems to sort out.

No chance of being in service for the BoB.

I did say I had problems with the time frame.

Cheers
Steve

 

[Denniss]

This special cooling system was meant for a record flight but not for standard production models.

 

[wiking85]

Soooo,it seems that Focke-Wulf were keen to use an evaporative cooling system in conjunction with the DB 601 A on their Fw 187.

Focke-Wulf and Daimler Benz cooperated on developing such a system with the second DB 601 A prototype. Testing,not in an airframe but on stands,was completed in July 1939. The first test run of the system in a Fw 187 was on the port engine of V5 on 15th September 1939. You'll notice that at least as far as the British and French are concerned WW2 has already started and the airframe/engine combination has not yet flown.

The testing of the DB 601 engines (V40 and V 42) continued into 1941,there were plenty of problems to sort out.

No chance of being in service for the BoB.

I did say I had problems with the time frame.

Cheers
Steve

Again, the change happens when the prototype is given the engines it requests from the beginning, which is the Db600 at first and then later the Db601 when it becomes available in early 1938. So the testing and development period would happen over two years, from May 1937-May 1939.
The Jumo 210 is never tested in this scenario and the DB601 is used as soon as it becomes available. Its eminently doable provided the Jumo diversion is not taken, which in the scenario I laid out in the OP would be the case.

 

[tomo pauk]

The P-51 had a laminar flow wing only in theory. Both US and British aerodynamicists doubted this in real flight conditions and a very long and thorough German investigation concluded that.

"These measurements clearly revealed the fact that the laminar flow effect completely disappeared at real flight Reynold Numbers."

And

"the performance of the Mustang could not be attributed to its laminar flow airfoil. It was the overall low drag design of this aircraft with clean surfaces including the careful design of the radiator that was the key of its good performance."

Cheers

Steve

The Germans also come to the conclusion that the wing Cd of P-51 was lower than F-190 (0.0072 vs. 0.0089, all at lift coefficient of 0,2), the same (laminar-flow) wing tailored upon NACA design 45-100 that was allowing for a Cd of 0.0068 if the lift coefficient is at 0,15.
Sure enough that in practice it was impossible to keep the laminar flow, the workmanship that built kept the planes in fine condition was crucial in wing keeping the wing drag as close as possible to a theoretical laminar wing.
I'm not saying that all of the low drag was because of the wing, but contribution of the wing to the low overall drag should not be downplayed.

 

[parsifal]

Havent read all the thread guys, so apologies if my comments are repeats.

Early on , one of the assumptions is that there would be 300 FW 187s available, each using 2 of the precious DB 601s. I assume those 300 will come as a replacement for the Me 110 units.

However, I doubt that as a financial burden that you can make a straight 1 for 1 conversion. The FW 187 was later development, requiring its own R&D and all the costs with setting up an additional production line. The type is inherently newer than the Me 110, and by August 1940, there were only 248 available, though 350 had participated in the BOF. Getting 300 of a newer, untested type into service whilst not producing the Me 110 will have some rather dire effects on the force structure. All those 350 Me110s that participated in the BOF would not be available, which means a higher attrition rate I think on the Me109 forces in the BOF. You might think that with 350 less a/c to fight the BOF, the LW might only take an additional 110 fighter losses. However I disagree. During the BOF, the LW took full advantage of the range and firepower of the Me110s and this, I think had a multiplying effect on French fighter lossese. Its anyones guess as to how many additional losses the absence of Me 110s in the BOF would have on LW force structure, but I dont think it out of the realm of possibility to say that the total forces entering the BOB might be 5-600 less than what was historical (that includes bombers lost because they were not provided with Zerstorer escort).

So, into this hypothetical equation we need to make allowance for the increased cost of a new type, the increased cost of setting up a new production line, and the additional losses caused by the absence of certain critical elements of the LW in the campaigns leading up to BOB. Its a matter of opinion, but i think it entirely possible that the LW would start its BoB with 5-800 less a/c than it did, because it wanted a second fighter in its inventory.

 

[tomo pauk]

Interesting - I'll start a new thread, importance of Bf-110 in early 1940.

 

[wiking85]

Havent read all the thread guys, so apologies if my comments are repeats.

Early on , one of the assumptions is that there would be 300 FW 187s available, each using 2 of the precious DB 601s. I assume those 300 will come as a replacement for the Me 110 units.

However, I doubt that as a financial burden that you can make a straight 1 for 1 conversion. The FW 187 was later development, requiring its own R&D and all the costs with setting up an additional production line. The type is inherently newer than the Me 110, and by August 1940, there were only 248 available, though 350 had participated in the BOF. Getting 300 of a newer, untested type into service whilst not producing the Me 110 will have some rather dire effects on the force structure. All those 350 Me110s that participated in the BOF would not be available, which means a higher attrition rate I think on the Me109 forces in the BOF. You might think that with 350 less a/c to fight the BOF, the LW might only take an additional 110 fighter losses. However I disagree. During the BOF, the LW took full advantage of the range and firepower of the Me110s and this, I think had a multiplying effect on French fighter lossese. Its anyones guess as to how many additional losses the absence of Me 110s in the BOF would have on LW force structure, but I dont think it out of the realm of possibility to say that the total forces entering the BOB might be 5-600 less than what was historical (that includes bombers lost because they were not provided with Zerstorer escort).

So, into this hypothetical equation we need to make allowance for the increased cost of a new type, the increased cost of setting up a new production line, and the additional losses caused by the absence of certain critical elements of the LW in the campaigns leading up to BOB. Its a matter of opinion, but i think it entirely possible that the LW would start its BoB with 5-800 less a/c than it did, because it wanted a second fighter in its inventory.

Based on the timeframes we are talking about the Fw187 would also be in service by the BoF. It won't have the same numbers as the Bf110 units I'd think, but they would be available and therefore filling the role of the Bf110.
The real difference would be in Poland, but the Bf110 had hardly entered service by then and was barely usable historically until it started taking the Db601 about that time. IIRC the Bf110 units had to use Me109 in Poland because of severe shortages of Bf110s.

Once again, assuming the Fw187 development follows the usual 24 months of development from the first prototype entering testing to serial production, the Fw187 would be ready in May 1939 for serial production; within a year (by May 1940) there would be several units fielding Fw187s operationally ready. It may only be two Geschwader, but even three is not unthinkable in one year from the start of production.

 

[nuuumannn]

No one has answered my question as to whether the Fw 187 was going to be fitted with self sealing tanks or armour plating, which would change weight figures, and as Delcyros astutely pointed out, in 1940, the aerodynamics of the Fw 187 would need to change to produce the performance that is being bandied about here. This would not have been able to be done in time for the Battle of Britain. The Hornet is a good example, since if it was fitted with chunky radiators like the Fw 187s under its propeller, the drag would surely effect its speed (and its looks; although this is not consequential, it is important since the Hornet is one attractive aeroplane ).

These radiators' surface area would also need to be enlarged to compensate for the extra power output of the DB 601s. Take the Spitfire for example; look at the difference in surface area of its radiators between the Mk.V, Mk.IX and XIV fitted with Griffon engines.

Also, as I mentioned earlier, none of the Fw 187 proponents have acknowledged that if it did have such sterling performance, what would the British response be? As I said, you can sure as heck be certain they wouldn't just sit on their hands.