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View Full Version : Brewster B-239 and F2A-2's speed incorrect.



GerritJ9
04-03-2005, 04:21 AM
Testing straightline performance for various fighters in FB/PF reveals the following maximum IAS:

B-239: 350 kph at 5000m
F2A-2: 370-380 kph at 5000m.
Hurricane IIB: 420 kph at 5000m.
Ki.43: 390 kph at 5000m.
Ki.61: 420 kph at 5000m.
A6M2: 390-400 kph at 5000m.

However, data published in various sources suggests that the B-239 and F2A-2 are both undermodelled as far as straightline speed is concerned. The B-239€s top speed at 4,500m is listed as 483 kph, or 300 mph TAS which translates to an IAS of 373 kph. For the F2A-2, the speed at 4,500m is listed as 554 kph TAS, or 344 mph which translates to 428 kph IAS.
Figures listed for the Ki.43-1a are 308 mph at 13,125 ft, or 495 kph at approximately 4,000m which gives an IAS of 392 kph..
Hurricane IIB is listed at 322 mph at 13,500 ft or 518 kph at approximately 4,000m, giving an IAS of 410. Performance increases to 342 mph at 22,000 ft or 550 kph at approximately 7,000m. IAS is 382 kph at this altitude.
Ki.61-1a is listed at 348 mph at 16,400 ft or 560 kph at approximately 5,000m, giving an IAS of 422 kph.

So, while Hurricane IIB, Ki.43-1a, A6M2 and Ki.61 seem to be modelled correctly as far as speed is concerned, the Brewster variants in FB/PF are clearly much too slow. This needs to be corrected.

Reference sources:
Warplanes of the Second World War, Fighters Volumes 2, 3 and 4 by William Green.
F2A Buffalo in Action by Jim Maas, ISBN 0-89747-196-2.
Le Brewster Buffalo by Jean-Louis Couston, ISBN 2-914017-25-1.
Various Profile Publications.

As a matter of potential interest, the speed figures for all Buffalo variants which saw action in the Pacific theatre are:

B-239: TAS 483/300 kph/mph (IAS 373 kph) at 4,500m. (Couston)
F2A-2: TAS 554/344 kph/mph (IAS 428 kph) at 4,500m. (Maas/Couston)
B-339C: TAS 528/328 kph/mph (IAS 408 kph) at 4,500m.(Couston)
B-339D: TAS 545/338 kph/mph (IAS 421 kph) at 4,500m.(Couston)
B-339E: TAS 530/330 kph/mph (IAS 409 kph) at 4,500m.(Maas). Green lists the B-339E€s top speed at 313 mph at 13,500 ft however- 504kph at approximately 4,000m or 397 kph IAS.
F2A-3: TAS 517/321 kph/mph (IAS 399 kph) at 4,500m. (Green/Maas/Couston)

GerritJ9
04-03-2005, 04:21 AM
Testing straightline performance for various fighters in FB/PF reveals the following maximum IAS:

B-239: 350 kph at 5000m
F2A-2: 370-380 kph at 5000m.
Hurricane IIB: 420 kph at 5000m.
Ki.43: 390 kph at 5000m.
Ki.61: 420 kph at 5000m.
A6M2: 390-400 kph at 5000m.

However, data published in various sources suggests that the B-239 and F2A-2 are both undermodelled as far as straightline speed is concerned. The B-239€s top speed at 4,500m is listed as 483 kph, or 300 mph TAS which translates to an IAS of 373 kph. For the F2A-2, the speed at 4,500m is listed as 554 kph TAS, or 344 mph which translates to 428 kph IAS.
Figures listed for the Ki.43-1a are 308 mph at 13,125 ft, or 495 kph at approximately 4,000m which gives an IAS of 392 kph..
Hurricane IIB is listed at 322 mph at 13,500 ft or 518 kph at approximately 4,000m, giving an IAS of 410. Performance increases to 342 mph at 22,000 ft or 550 kph at approximately 7,000m. IAS is 382 kph at this altitude.
Ki.61-1a is listed at 348 mph at 16,400 ft or 560 kph at approximately 5,000m, giving an IAS of 422 kph.

So, while Hurricane IIB, Ki.43-1a, A6M2 and Ki.61 seem to be modelled correctly as far as speed is concerned, the Brewster variants in FB/PF are clearly much too slow. This needs to be corrected.

Reference sources:
Warplanes of the Second World War, Fighters Volumes 2, 3 and 4 by William Green.
F2A Buffalo in Action by Jim Maas, ISBN 0-89747-196-2.
Le Brewster Buffalo by Jean-Louis Couston, ISBN 2-914017-25-1.
Various Profile Publications.

As a matter of potential interest, the speed figures for all Buffalo variants which saw action in the Pacific theatre are:

B-239: TAS 483/300 kph/mph (IAS 373 kph) at 4,500m. (Couston)
F2A-2: TAS 554/344 kph/mph (IAS 428 kph) at 4,500m. (Maas/Couston)
B-339C: TAS 528/328 kph/mph (IAS 408 kph) at 4,500m.(Couston)
B-339D: TAS 545/338 kph/mph (IAS 421 kph) at 4,500m.(Couston)
B-339E: TAS 530/330 kph/mph (IAS 409 kph) at 4,500m.(Maas). Green lists the B-339E€s top speed at 313 mph at 13,500 ft however- 504kph at approximately 4,000m or 397 kph IAS.
F2A-3: TAS 517/321 kph/mph (IAS 399 kph) at 4,500m. (Green/Maas/Couston)

GerritJ9
04-05-2005, 02:04 PM
B-339C is the initial version built for the Netherlands East Indies, with 1,100 hp Cyclones. 24 built.
B-339D is the second version built for the Netherlands East Indies, with 1,200 hp Cyclones. 48 built. The original intention was for all 72 KNIL Brewsters to be equipped with 1,200 hp Cyclones, but Wright could not supply sufficient 1,200 hp Cyclones for all aeroplanes and the first 24 were equipped with 1,100 hp Cyclones instead. Otherwise identical to the B-339C.
B-339E is the version built for the R.A.F. as Buffalo Mk. 1. Fitted with 1,100 hp Cyclones.

Aimosika
04-05-2005, 02:27 PM
Well in my opinion B-239 here is the Finnish version with much weaker engine than the original..?

GerritJ9
04-05-2005, 02:32 PM
The B-239 was a denavalized version of the F2A-1. The F2A-1 had a 950 hp Wright R-1820-34 Cyclone, the B-239 had the Wright R-1820-G5 Cyclone, also of 950 hp. And yes, the B-239 is the version sold to Finland.