What was wrong with the F4F Wildcat?

[HoHun]

Hi Amsel,

>Here is the text of a despatch from Admiral Nimitz to
Admiral King sent on 20 June 1942:

Wow, that makes Thach's statement look like a rather cautious comment in comparison! Thanks a lot!

Nimitz demanding Army aircraft ... that probably didn't make him popular in the Navy

Apparently, the Navy's victory at Midway did not leave Nimitz with a false sense of satisfaction with his main fleet fighter ...

Regards,

Henning (HoHun)

 

[Amsel]

Nimitz I think expected that the Japanese would recognize that they were using bad tactics and improve on them but they never did. The Japanese thought they were doing just fine until they ran into the F4U and P-38s and other 1943 aircraft. It seems that tactics trumped the supposed superiority of the Zero fighter. As far as giving the Marine units P 40's some say the Marines were better off with the Wildcat due to the fact that the Japanese bombers were coming in at about 25,000 feet.

 

[Clay_Allison]

Nimitz I think expected that the Japanese would recognize that they were using bad tactics and improve on them but they never did. The Japanese thought they were doing just fine until they ran into the F4U and P-38s and other 1943 aircraft. It seems that tactics trumped the supposed superiority of the Zero fighter. As far as giving the Marine units P 40's some say the Marines were better off with the Wildcat due to the fact that the Japanese bombers were coming in at about 25,000 feet.

...we'd work like hell to get to to climb to 23,000-24,000 feet. At that
altitude when you malke a turn you lose 1,000 ft, and its very easy to
stall out. In theory the F4F had a higher service ceiling but not in
practice. You'd look up and there sit the Japs at 30,000 ft looking
right down at your gazoo. A real fun time. You couldn't get that bird
much higher than 24,000: not you, not Jesus, nobody. The bird
Wouldn't go any higher.

Maybe not though.

 

[renrich]

Nimitz in June, 1942, was only reflecting the viewpoint of pilots like Thach who were fresh from the Midway battle and who were already critical of the changes made to the F4F3 that resulted in the F4F4. If, and this is a big if, Vought had been a bigger company and if the urgency had been there, the F4U could have been available in early 1942 with most of the bugs out which hindered it's use on carriers. The long gestation period of the Corsair was most unfortunate for the USN. The USN fowarded a request to Vought for the proposal on a production aircraft in Nov., 1940. A contract for 584 F4U1s was signed in June 1941. The Navy accepted the first two F4U1s in July 1942 and the Corsair was still not ready for operations off of carriers.

 

[Amsel]

Maybe not though.

True, but my comparison was to the P-40. The P-40 struggled at 18,000'. On the E and K models it could reach 22,000' but struggled maybe flying only barely above stall speed at full throttle. If the nose was raised or the guns were fired it would go into a stall. The wildcat could still fight at 24,000' where the p-40s at altitude would be sitting ducks.

 

[HoHun]

Hi Amsel,

>True, but my comparison was to the P-40. The P-40 struggled at 18,000'. On the E and K models it could reach 22,000' but struggled maybe flying only barely above stall speed at full throttle. If the nose was raised or the guns were fired it would go into a stall. The wildcat could still fight at 24,000' where the p-40s at altitude would be sitting ducks.

When Nimitz complained about the poor performance of the F4F-4 and demanded the adoption of the P-40 by the Navy, he well-advisedly called for the P-40F with its Merlin engine featuring a two-speed (but single-stage) supercharger.

This gave superior altitude performance if you compare it to the P-40 models historically flown by the USAAF in the Pacific hemisphere, though the heavy weight of the P-40F countered some of that advantage, and it was hardly an improvement over the F4F-4 in climb rate, and a step backward in turn rate.

On the other hand, it was much faster than both the F4F-4 and the A6M2 at all altitudes, and that advantage must have been appreciated by the Navy, or they wouldn't have called for the type ...

Regards,

Henning (HoHun)

 

[MikeGazdik]

I had never read that before, about Nimitz asking for P-40's! I love it! I can see medium blue over white P-40's !!!

 

[Marshall_Stack]

It is interesting about the navy considering P-40s. Along with the other comments here, it is also surprising because they exclusively used radial engines.

Hw about considering the P-43? It had a turbosupercharger and was close to the Wildcat as far as speed.

 

[HoHun]

Hi Marshall,

>Hw about considering the P-43? It had a turbosupercharger and was close to the Wildcat as far as speed.

Good question. Here is an older comparison I did quite a while back based on what little data I could find on the P-43.

I guess it would be able to hold its own against the A6M2 above 5 km altitude - the higher the better -, but below that, it wouldn't be so good (though probably better than the F4F-4).

Regards,

Henning (HoHun)

 

[Marshall_Stack]

HoHun,

How do you make these graphs?

 

[HoHun]

Hi Marshall,

>How do you make these graphs?

Do you mean the technical process of turning numerical data into graphs, or do you mean the method of arriving at the numerical data?

For the former, I mostly use Gnuplot and sometimes a spreadsheet.

For the latter, some aerodynamic calculations based on the engine power curve (which in the case of the P-43 is an educated guess), with calibration of the total drag done according to the historical speed data.

Obviously, the more accurate and complete the source data, the more reliable the results. For the P-43, there was little source data, so don't expect perfect accuracy.

Regards,

Henning (HoHun)

 

[Marshall_Stack]

HoHun, Yeah I was just curios on how you produced the graphs. Thanks for the info.

Does anyone know why the FM-2 used a single stage supercharger vs the two stage on the Wildcat? Was it to conserve weight and/or fuel?

 

[Clay_Allison]

Going back for a moment to the original question fo the thread. Does anyone think a bigger 4-blade prop would have helped? That Twin Wasp wasn't awesome but it had decent horsepower. I think it had enough torque to pull a little more air per revolution.

 

[HoHun]

Hi Clay,

>1. Wider eliptical wings for more lift and wing surface without making it more difficult to pack into escort carriers. Level top speed would not be helped but since it was a brick, it would still dive fast and be far more maneuverable in a dive than the Zero, plus it would be able to climb effectively and turning might well be better as well.

Hm, if you're aiming for an improved climb rate and manoeuvrability, the first thing to look at should be a possible weight reduction. The F4F-4 had an empty weight of 2670 kg, compared to the (carrier-capable!) Me 109T-2's empty weight of just 2262 kg. (That's flying weight minus fuel, oil, ammunition and pilot in both cases.)

This difference of 400 kg is your weight reduction potential ... exploit it fully, and you will gain 2 m/s climb rate and 3 degree per second turn rate at sea level.

>2. Just at a glance, the prop on the F4F looks tiny. I think a 4 or 5 blade prop with big fat air-eating blades would take better advantage of the 1200 HP offered by the Twin Wasp.

As a rule of thumb, normally you would prefer to have the smallest number of blades that can transfer the required power. The propeller of the Wildcat was quite adequate ... not much different from that of the Me 109T-2, which offered far superior performance on about the same engine power.

Drag reduction would be the second priority for the F4F-4 (or maybe even the first).

For the Brewster F2A Buffalo, the NACA prepared a report showing the influence of every aerodynamic imperfection, which added up to a pretty bad penalty. (Some of them were unavoidable on a real aircraft, of course), but similar wind tunnel tests on the Grumman F4F might have helped to make the type a bit faster, I imagine.

Regards,

Henning (HoHun)

 

[Marshall_Stack]

VMF-121 pilot Roger Habermane

...we'd work like hell to get to to climb to 23,000-24,000 feet. At that
altitude when you malke a turn you lose 1,000 ft, and its very easy to
stall out. In theory the F4F had a higher service ceiling but not in
practice. You'd look up and there sit the Japs at 30,000 ft looking
right down at your gazoo. A real fun time. You couldn't get that bird
much higher than 24,000: not you, not Jesus, nobody. The bird
Wouldn't go any higher.

Slaterat

I have read this quote in "Fire in the Sky" and a few pages later there is an account of F4Fs flying at 26,000 or 28,000 feet. So which it, can't get any higher than 24,000 or not?

 

[delcyros]

It depends on the actual flying weight. This weight changes as the fuel get´s burned. The plane gets lighter the service ceiling increases.

 

[Vincenzo]

HoHun, Yeah I was just curios on how you produced the graphs. Thanks for the info.

Does anyone know why the FM-2 used a single stage supercharger vs the two stage on the Wildcat? Was it to conserve weight and/or fuel?

simply was a different engine

 

[Marshall_Stack]

simply was a different engine

But why did the Navy select an engine with only a single speed supercharger when its other fighters had the two stage?

 

[Vincenzo]

maybe, this is my speculation, the 2 staged engine need on other aircrafts more usefull for war

 

[Skip M]

Does anyone know why the FM-2 used a single stage supercharger vs the two stage on the Wildcat? Was it to conserve weight and/or fuel?

The FM-2 was planed for escort carriers performing ASW and close support. The new engine was lighter and had better power down low. The same reason that the Navy's B-24 version PB4Y-2 got rid of the turbo chargers to save weight.