Performance Comparison: Vought F4U-1D Corsair vs. Grumman F6F-5 Hellcat

[HoHun]

Hi everyone,

Based mainly on the BuAer data sheets for the Vought F4U-1D Corsair and the Grumman F6F-5 Hellcat, I have prepared a performance comparison of these two types.

Though the BuAer data sheets provide a lot of data, it's partially self-contradictory, generic, or possibly wrong, so it required quite some effort and cross-checking with other data sources to distill the following comparison from it.

Note that within my analysis the F4U-1D and F6F-5 are considered to have essentially the same engine, with the only (irrelevant) difference between (respectively) their R-2800-8 and R-2800-10 being that the former is fitted with an updraught carburettor and the latter with a downdraft one. (If referred to as R-2800-8W and R-2800-10W, these are the same engines - I'm not sure if the "W" is even an official designation.) The ratings are taken from the BuAer F4U-1D data sheet, the F6F-5 BuAer data sheet actually differs slightly though both engines are in fact as good as identical. (Thanks to Pasoleati for pointing this out!)

The War Emergency Power, Water or Combat power is considered to be achieved at 60" Hg boost pressure in all three supercharger configurations (high speed, low speed, engine stage only). The BuAer F4U-1D data does not provide boost pressure figures, but Military and Normal power probably don't have uniform boost pressures over all three supercharger configurations. I'll leave the question of the absolute values open.

Combat and Military power are achieved at 2700 rpm, Normal power is achieved at 2550 rpm.

One difference resulting from the engine installation is that the F4U-1D has the benefit of ram effect even in the "neutral" gear when the auxiliary supercharger stage is skipped, while the F6F-5 draws air from the engine compartment and thus loses the ram effect. (I haven't been able to confirm that the F4U-1D really works like that from technical descriptions or diagrams, but an article on the two types by Grumman test pilot Corky Meyer pointed this out, so I went with it. Any extra data you might have would be welcome.)

One area where I have no data on is the exact amount of exhaust thrust in both aircraft. The good fit of my calculated F4U-1D data with the BuAer data shows that I'm probably very close to the real figures, but the fit with the BuAer F6F-5 data is not so good, and this might indicate that the exhaust system of the F6F-5 generates more direct thrust (though I doubt it, as F6F-5 speed data from different sources is generally mismatched to begin with). Thus I assumed the engines to be so similar that they gave the same amount of exhaust thrust for both types.

Regards,

Henning (HoHun)

[HoHun]

Hi again,

Here some graphs to show the match of my calculations with the BuAer F4U-1D data.

It pretty good for speed, but not so good in climb. My calculations might be slightly optimistic due to not accounting for the extra drag from open cowl flaps in a standard climb. I figure this effect to be in the region of 1 m/s for most types.

Regards,

Henning (HoHun)

[HoHun]

Hi again,

And here is the comparison of the F6F-5 data from my calculations to that from the BuAer data sheets.

The difference in the speed graphs is worth noting. The different slope in the Military power graph looks odd, but as there are other F6F-5 data sets around with a difference of similar magnitude in the opposite direction, I'm not overly concerned. The gap in top speed under Combat power is quite interesting, but as there is a similar gap in the climb speed graph with shows available power quite realistically, it appears that the BuAer did not base their Combat power performance on the 2700 rpm, 60" Hg setting I used. As I have found an F6F-5 Specific Engine Flight Chart showing the use of just these settings on the R-2800-10 (with a 5 min limitation), I'm not sure of the reasons for the apparently different BuAer assumptions.

Regards,

Henning (HoHun)

[palindrome1959]

I vaguely remember reading somewhere that the Corsair could engage in a turning fight with a Zero but the Hellcat could not. Given all else being equal, would this not give the edge to the Corsair?

[HoHun]

Hi Palindrome,

>I vaguely remember reading somewhere that the Corsair could engage in a turning fight with a Zero but the Hellcat could not. Given all else being equal, would this not give the edge to the Corsair?

This would seem so, but from the above analysis, there appears to be hardly any difference in turning capability between the US Navy fighters. I admit that this came as a bit of a surprise to me, too!

Other anecdotal accounts seem to give the F6F the turning advantage over the Corsair, so this was the direction in which I expected a difference, but anecdotes are always difficult to assess ... too many unknown variables, usually.

With regard to the A6M, from the technical data I don't believe that there is any way the heavy US fighters could hope to turn with the A6M. However, they enjoyed quite a number of other advantages to make up for this!

Regards,

Henning (HoHun)

[lesofprimus]

My Grandfather flew both and said unequivocally that the 1-D was much better than the Hellcat, and at higher speeds had no problem turning with and inside the A6M...

He beat many a Squid in their Cats, but this may have been to experience rather than airframe as he had 3 Tours under his belt....

Great work HoHun, alot of work went into this thread and we all appreciate it.....

Thanks...

[HoHun]

Hi Les,

>My Grandfather flew both and said unequivocally that the 1-D was much better than the Hellcat, and at higher speeds had no problem turning with and inside the A6M...

Good point - with a higher G limit and short of the stall border, the US fighters do indeed have one region of the envelope where they'd outturn the Zero. I suspect you'd not normally stay long in this region though as it would burn your energy very quickly. Of course, that might be just what you'd need to get into position ...

>Great work HoHun, alot of work went into this thread and we all appreciate it.....

Thanks a lot for the encouragement - when I wasn't getting any comments at first, I thought to myself, "Maybe I was a bit too dry and technical this time" :-)

Regards,

Henning (HoHun)

[lesofprimus]

Ur welcome Henning.... This kind of work is hard to come by, atleast the kind that has been researched and professionally delivered as u have....

[rochie]

dont give up Henning i love reading these charts and such you provide but dont have the knowlage to pass comment so i read them to help improve my technical know how.

keep up the good work mate
Karl

[Ron]

I appreciate the authentic performance data like the P-38 and Yak links you have. I look forward to more. I savor the performance info on rare birds like the Sagittario which was a refined design for it's time. I mean 421 mph at what.. 6 or 7,000' with the same engine as the contemporary Bf 109 Gustav in 1943. It got the attention of the Luftwaffe. Imagine if it had been mass produced in place of the inferior 109! Anyway it deserved more than the 48 + that were produced. I guess it's things like this that adds interest to the subject.
-RB

[tomo pauk]

Hi, Ron,

Any info (not Wiki, please ) that suports the speed of Re.2005 you've posted?

[jpatrick62]

There seems to be a lot of disconnect between those who flew the F4U and modern aircraft experts along with flight sim people. Reading about the F4U from the modern experts you would get the idea that it was a poor turner and a horrible dogfighter with poor climb. The only real advantage it had was speed, roll rate and toughness. However, most of the people who flew the plane seem to indicate it was the hot ship. Most do indicate it took some time to adjust to the plane's flight envelope and unique stall patterns. This indicates to me that familiarity with the plane allowed the WW2 pilots to bring it's advantages into play.