Brewster Buffalo dive speed and handling

[dtango]

Lots of different issues being tossed in here.  The title of the thread and ardy's OP deals specifically with 1) B239 dive performance, 2) B239 energy retention.  Ardy (and probably others) has questioned how the B239 performs relative to other aircraft in these areas in AH.  The question about the performance is stated in a way as if it's known objective fact.  There are opinions and then there are facts.  If it's indeed a fact then people need to present the data and the analysis to demonstrate the fact.

I've purposely tossed data out there to ardy and for anyone else to examine to help them analyze the data to see if their theory is indeed fact or not.

Why is some of the data I pointed out relevant?  There's a scattering of F2A variants listed in the reports none of them specifically say B239 so none of them are useful right?  It would be foolish to dismiss them in this manner.  I'm tempted to be obtuse about it all and stop there because in my old age I have neither the time nor energy anymore to explain why it's relevant .  I'll at least toss some bones out there!

1) Are you curious about the dive performance of the F2A?  Well the "Compressibility Phenomena" report has dive time history data for an F2A-2 at ~5500 lbs going from 0 to max dive limit.  If you don't think a 5500 lbs F2A-2 is similar enough to a B239 then just apply the aerodynamics & adjust for whatever differences you think the extra horsepower might mean on the dive performance.

2) Want to know the energy retention / sustained level turn performance of the F2A?  Look at the "Calculated & Measured Turn Performance of a F2A-3" report which gives you performance of a F2A-3 at 6500 lbs from clean to full flaps.  Apply the aero adjusts and calculate to see what the effect might be by lightening the the load and reducing the horsepower to match that of a B239.

By the way gyrene- just a point of reference, the B239's engine is rated at 1000 hp military at sea level.  The F2A-2/3 is rated at 1200 hp military at sea level.

Tango
412th FS Braunco Mustangs

[gyrene81]

By the way gyrene- just a point of reference, the B239's engine is rated at 1000 hp military at sea level.  The F2A-2/3 is rated at 1200 hp military at sea level.

R-1820-40 not the R-1820-22 or 34...I've been looking at the wrong engines, and there is ~100hp discrepancy between references.  

Thanks for pointing it out dtango... 

[Saxman]

Well, ok that was my assessment after lots of hairy eyeball reading because I object to having the Finnish B-239 substituted for F2A-1/2s in PTO special event setups.

Actually, it's not substituting for F2A-1/2s in PTO special events setups at all. It's substituting for:

F2A-3 (USMC)
B-339 (Dutch)
B-339E (British/Commonwealth)

From what I gather, the 339 used by the Dutch wasn't TOO far off the 239 we actually have. I think I read the British overloaded the 339E even worse than what the F2A-3 was.

The best option is to add the F2A-3 as a separate aircraft from the 239. That would cover the widest variety of aircraft, as the F2A-1/2 were already out of combat by the beginning of the war. This would give the F2A-3 for the Americans and 339E, with the 239/339 for the Finns/Dutch.

[dtango]

R-1820-40 not the R-1820-22 or 34...I've been looking at the wrong engines, and there is ~100hp discrepancy between references.  

Thanks for pointing it out dtango... 

You bet.  Dean lists in AHT the B239 using a R-1820-G5.  Graham White says the G series Wright R-1820's achieved improved performance due to inclusion of additional cooling fin area and a redesigned two-piece crankcase.

Tango
412th FS Braunco Mustangs

[AWwrgwy]

The kill/loss record for the F2A-3s at Midway was 17 went up and 5 returned. The kills credited were mostly bombers with a couple of possible Zekes.

Context?

On the morning of June 4, Admiral Nagumo launched his first strike with 108 aircraft, 36 Nakajima B5N2 Kate torpedo bombers, 36 Aichi D3A1 Val dive bombers and 36 Mitsubishi A6M2 Zero

So, 17 Buffaloes and 7 Wildcats, with unseasoned pilots, attacked 108 Japanese veteran pilots....

It had to be the planes....


wrongway

[Krusty]

B-239s may have had one engine, but that engine wasn't necessarily what the Finns put into it. Remember they were scrambling for anything they could, similar to the AVG. I think they put the engines from a DC-3 in them, or some other transport?

Saxman, the 339 was an export version of the F2A3.

239s would have less horsepower and less efficient props than the F2A2s.

Also, the Brewster was supposed to be somewhat unstable, and yet in-game is probably one of the better gun platforms. Before being shipped to Finland, the pilot armor, the self-sealing fuel tanks, and the tail hook were removed. Note that the Finns themselves restored the pilot armor once they received them.

Overall the weight of a tail hook and self-sealing fuel tanks isn't that much, yet somehow we've been given a Brew in AH that performs like a zeke. Something that never happened in real life. We're talking 100kg and change between the dry weights of the B-239 and the F2A2 here. That's not going to make a total pig that suffers in all theaters suddenly become a wunder-plane.

Overall it's like Karnak says, unfair to use it in any PTO setup.

[321BAR]

The Brewster B-239 is NOT the crappy Buffalo. the Buffalo was the American Brewster F2A2 and the F2A3 that was weighed down substantially with too much armor. The B-239 is a lighter and more maneuverable Brewster. If you want them in PTO scenarios we need them to be the F2A2s and F2A3s. The 239 was the Swedish version which outflew the I-16s and had approximately a 60 to 1 K/D versus the EW Russian aircraft. Many Swedish aces scored more than 20 victories without being shot down. One ace scored over 60 kills against the Russians. The Dutch in the PTO had the 339 which was almost like the 239 in maneuverability but could not stand against the A6M2s that the japanese used. Almost no Dutch Brewsters killed any Japanese.

[321BAR]

B-239s may have had one engine, but that engine wasn't necessarily what the Finns put into it. Remember they were scrambling for anything they could, similar to the AVG. I think they put the engines from a DC-3 in them, or some other transport?

Saxman, the 339 was an export version of the F2A3.

239s would have less horsepower and less efficient props than the F2A2s.

Also, the Brewster was supposed to be somewhat unstable, and yet in-game is probably one of the better gun platforms. Before being shipped to Finland, the pilot armor, the self-sealing fuel tanks, and the tail hook were removed. Note that the Finns themselves restored the pilot armor once they received them.

Overall the weight of a tail hook and self-sealing fuel tanks isn't that much, yet somehow we've been given a Brew in AH that performs like a zeke. Something that never happened in real life. We're talking 100kg and change between the dry weights of the B-239 and the F2A2 here. That's not going to make a total pig that suffers in all theaters suddenly become a wunder-plane.

Overall it's like Karnak says, unfair to use it in any PTO setup.

all negative information about the Brewsters were about the American Buffalo versions. The 239 was a somewhat ok aircraft for the Early War and the 339 was up there with it. but both could not out fly any Japanese aircraft. By the way Karnak, 100kg (250lbs) weight difference on a plane as big as my thumb is a MASSIVE difference in weight change.

[321BAR]

Actually, it's not substituting for F2A-1/2s in PTO special events setups at all. It's substituting for:

F2A-3 (USMC)
B-339 (Dutch)
B-339E (British/Commonwealth)

From what I gather, the 339 used by the Dutch wasn't TOO far off the 239 we actually have. I think I read the British overloaded the 339E even worse than what the F2A-3 was.

The best option is to add the F2A-3 as a separate aircraft from the 239. That would cover the widest variety of aircraft, as the F2A-1/2 were already out of combat by the beginning of the war. This would give the F2A-3 for the Americans and 339E, with the 239/339 for the Finns/Dutch.

the F2A-2 and F2A-3 American Buffaloes and the B-339E British Brewster were all weighed down too much by armor. the B-339 and the B-239 models were lighter and more maneuverable. the difference between the scenarios of the Swedes and the Dutch are what they flew against as i stated above

[Saxman]

the F2A-2 and F2A-3 American Buffaloes and the B-339E British Brewster were all weighed down too much by armor. the B-339 and the B-239 models were lighter and more maneuverable. the difference between the scenarios of the Swedes and the Dutch are what they flew against as i stated above

Actually, no, only the F2A-3 was. Boyington himself spoke highly about the F2A-2. It wasn't until the -3 that they really got overloaded. However NO "designated" F2A-2s saw combat during the war. All American Buffaloes at Midway were F2A-3s. The B-339C and D used by the Dutch was much closer to the F2A-2.

And Krusty,

From everything I've ever seen the 339C and D used by the Dutch was an ENTIRELY different animal from the F2A-3. She was actually much closer to the US F2A-2 (because the 339 was derived FROM the -2, NOT the -3) in weight and performance. The Dutch birds acquitted themselves fairly well against the Zero and Oscar, it was overwhelming numbers that really did them in.

The 239 we have is "close enough" to work for the 339C and D. Add the F2A-3 and that gives us the US and British/Commonwealth version.

[dtango]

Digressing from Ardy's OP...

The issue of weight...here are the variants being discussed in question and weights (per Dean's AHT):

Var.      Empty Wt      Gross Wt      No.A/C
F2A-1   3785 lbs      5055 lbs        11
B239      3744 lbs      5276 lbs*      44
F2A-2   4150 lbs      5419 lbs        43
339B      4020 lbs      5437 lbs        40
339E      4268 lbs      6112 lbs        170
339D      4282 lbs      6095 lbs        72
F2A-3   4765 lbs      6519 lbs        108

* 4 gun load out / 110 gal-fuel

Any which way you cut it, the weight difference between the B239 and the F2A-3 (used at Midway) is around ~1000 lbs.  Same airframe, same wing surface area, slight differences in powerplant hp...you don't even have to do all the fancy math to begin to understand why the B239 out performs the F2A-3.

Tango
412th FS Braunco Mustangs

[Krusty]

Also, spewing the "weighted down by armor" line is false. We took the armor OUT, the Finns put it back IN. Net gain: zero.

The reason the -3 was so heavy was the fuel it carried, and many sources will back this up. It had a 1600 mile range, longest range of any fighter at the time (so one source claims).

Fuel weight alone won't account for the handling issues present, and it wasn't armor. The empty weights weren't that far off from the previous models.

EDIT: Just saw dtango's post. Don't know why AHT has that much bloat between early and later models, did a sampling of online sources and they had the F2a2 and B239 as much heavier with empty weight.

[dtango]

+280 increased airframe weight (+172 for just the wings with no change in surface area)
+547 in new powerplant
+215 in fixed equipment

We haven't even tacked on differences in fuel weight (110 gals vs. 240) nor ammunition (.30/.50 mix vs. 4x.50's).

Tango
412th FS Braunco Mustangs

[Krusty]

From everything I've ever seen the 339C and D used by the Dutch was an ENTIRELY different animal from the F2A-3. She was actually much closer to the US F2A-2 (because the 339 was derived FROM the -2, NOT the -3) in weight and performance. The Dutch birds acquitted themselves fairly well against the Zero and Oscar, it was overwhelming numbers that really did them in.

I disagree. The B-339C/D/E was essentially a land-based version of the F2A3. The export versions varried very little from the end-of-production heavy, bloated models. As early as 1939 the USN put in the order for F2A-2s, and by Sept 1940 they had F2A-3s, and the first exports to Belgium which were diverted to the RAF may have been F2A2 standards, but all the other couple-hundred ordered after that were later standards. Even these first, earliest, models were trounced by Japanese forces the first time they went up in even numbers, losing 6 out of 12 and the Japanese only losing 1 or 2. They were promptly withdrawn and the AVG stepped in to relieve the pressure.

[Stoney]

Also, the Brewster was supposed to be somewhat unstable, and yet in-game is probably one of the better gun platforms.

So, in an early-war PTO setup, what's a better representation of the F2A-3, the B-239 or the F4F-4 with 4 X Mother Deuce?