P-51 vs. Hellcat

[Ivan1GFP]

FWIW, my vote is for the P-51 over the Hellcat. For the best of both types, it would be a P-51B/C versus the F6F-5.

The P-51 has the following advantages:
Level Speed
Diving Speed
Climb Rate
Roll Rate

They are equal in firepower for as long as it matters

The Hellcat has an edge in sustained turn.

I don't know which aircraft has better acceleration but with the climb rate advantage and power loading, the P-51 probably wins here as well. How can you win against someone who has every advantage except for low speed turns if he doesn't want to play your game? I don't think durability is enough.

- Ivan.

 

[HoHun]

Hi Davparlr,

>Tested boost 75 inches

As power data for 80" Hg accompanies the Mustang IV test, I just went ahead and tried to make (or actually made) some graphs for this power settings.

However, I found that these data points don't match the 67" Hg data points in a way that makes it likely that increasing boost after providing the correct fuel was the only change. I'm not sure, but the 80" Hg data looks a lot like the "Jumo 213 mit A-Lader als Bodenmotor" data, showing a Jumo 213 with increased boost and reduced compression ratio. Perhaps that's not just coincidence, but convergent evolution

Anyway, I proceeded more cautiously then and attempted to extrapolate power at 72" Hg from the data for 67" Hg. This went fairly well, and since 72" Hg is specifically mentioned in three quotes provided by Mike on his site, it's probably a good basis for a fair comparison to the F6F-5.

Here the graphs ...

Regards,

Henning (HoHun)

 

[davparlr]

Hi Davparlr,

>Tested boost 75 inches

As power data for 80" Hg accompanies the Mustang IV test, I just went ahead and tried to make (or actually made) some graphs for this power settings.

However, I found that these data points don't match the 67" Hg data points in a way that makes it likely that increasing boost after providing the correct fuel was the only change. I'm not sure, but the 80" Hg data looks a lot like the "Jumo 213 mit A-Lader als Bodenmotor" data, showing a Jumo 213 with increased boost and reduced compression ratio. Perhaps that's not just coincidence, but convergent evolution

Anyway, I proceeded more cautiously then and attempted to extrapolate power at 72" Hg from the data for 67" Hg. This went fairly well, and since 72" Hg is specifically mentioned in three quotes provided by Mike on his site, it's probably a good basis for a fair comparison to the F6F-5.

Here the graphs ...

Regards,

Henning (HoHun)

Those graphs look pretty good for your data points. That test shows a bit slower than other tests but probably within error. SL climb appears more closely related to 67".

http://www.wwiiaircraftperformance.org/mustang/p51d-15342-climb.jpg

75" was approved and often used, but 72" was the official AAF WEP setting so that is a good selection. Apparently the Brits tested to 80" but I have no evidence they used it.

 

[BIG BIRD]

The hellcat is just to slow.

 

[HoHun]

Hi Davparlr,

>That test shows a bit slower than other tests but probably within error.

I like the original data set since it is subject to the full British methodology, which usually gives good result with few self-contradictory effects and so on. There are (fortunately) many Mustang tests around, but some show effects that make me think "How on earth ...?"

>SL climb appears more closely related to 67".

Hm, interesting. This is a big difference as in addition to the greater climb rate, they also used a higher weight. As my climb calculation usually tends a bit towards the high side and I'm low in this case, I have to file this under "unexplained contradiction"

>75" was approved and often used, but 72" was the official AAF WEP setting so that is a good selection. Apparently the Brits tested to 80" but I have no evidence they used it.

I really wonder if they changed the compression ratio for the V-1 chaser engines ... I've never read about that before, but it would explain the apparent "kink" that results from connecting the data points directly.

From my latest graph with the 67" and 72 "Hg curves, you can graphically extrapolate the 75" Hg curves easily by just "sliding" the full-pressure bits towards higher performance by 60% of the difference between 67" and 72" Hg

By the way, the talk is of 80" Hg (on Mike's site, too), but the British apparently considered it +25 lbs/sqin which I convert to 80.82" Hg.

Regards,

Henning (HoHun)

 

[HoHun]

Hi again,

Well, I made a new set of generic engine power curves based on the 67" Hg power curve on Mike's site.

I found that the (admittedly slightly suspect) sea level power figure in the original data point does not scale well in the extrapolation, so I replaced it with a generic figure based on the temperature quotient between full throttle height and sea level.

This helped climb rate a bit, but (unavoidably) also resulted in a higher sea level speed. Take this with a grain of salt - the source data just appears not to be perfectly coherent.

So here a set of curves for the Mustang IV at different power settings, compared to the F6F-5 ...

Regards,

Henning (HoHun)

 

[davparlr]

Hi again,

- the source data just appears not to be perfectly coherent.

It seems that those of us that try to make something coherent from what data we have are doomed to despair. Your charts looks as good as I've seen. Good work.

 

[The Jug Rules!]

STANG..most definitly...Being able to break off combat at will is a bigger advantage then most think--I love leaving La7's and spitfires in the dust with my jug in il2, amids the catcalls of "Boom and zoom noob", and "You wimp TURN AND FIGHT"

I think a hellcat would only take a mustang in a low speed turnfight as the Stang's instability would probably do it in.


and sorry for the long Hiatus guys...good to see you guys are still at it in here

 

[eddie_brunette]

F6F for me

edd

 

[Soren]

The P-51 is way faster, and like most fighter pilots will confirm, speed is life!

The F6F should turn better at low alt and at slow speeds, but thats all its got going for it.

 

[drgondog]

STANG..most definitly...Being able to break off combat at will is a bigger advantage then most think--I love leaving La7's and spitfires in the dust with my jug in il2, amids the catcalls of "Boom and zoom noob", and "You wimp TURN AND FIGHT"

I think a hellcat would only take a mustang in a low speed turnfight as the Stang's instability would probably do it in.


and sorry for the long Hiatus guys...good to see you guys are still at it in here

What 'instability' are you talking about??

 

[The Jug Rules!]

Mustangs were know to be a bit unstable, especially with fuel in the aft fuselage tank, witch im shure in a low speed turnfight would probably end with the mustang spinning in

 

[drgondog]

Mustangs were know to be a bit unstable, especially with fuel in the aft fuselage tank, witch im shure in a low speed turnfight would probably end with the mustang spinning in

The SOP was to use the fuselage tank at least to 25 gallon point. At that point the 51 no longer had an aft cg issue. Most of the time that 60 (of 85) gallons would be used up by the time it was crossing the English Channel. Additionally, the Fuse tank was only filled beyond 25 gallons in the case of very long escort or ferry runs.

The LW failed to exploit this temporary condition by virtue of not attacking Brit airfields.

If, on the other hand a Mustang did engage w/fuse tanks full he was risking a violent snap roll in a sharp turn. Rarely happened.

 

[Watanbe]

FWIW, my vote is for the P-51 over the Hellcat. For the best of both types, it would be a P-51B/C versus the F6F-5.

The P-51 has the following advantages:
Level Speed
Diving Speed
Climb Rate
Roll Rate

They are equal in firepower for as long as it matters

The Hellcat has an edge in sustained turn.

I don't know which aircraft has better acceleration but with the climb rate advantage and power loading, the P-51 probably wins here as well. How can you win against someone who has every advantage except for low speed turns if he doesn't want to play your game? I don't think durability is enough.

- Ivan.

Thats exactly what I think! In all the key areas the P51 seems the better choice! The Hellcat did its role perfectly, it was produced to out perform its competition at the time, be rugged, easy to produce and be operable from a carrier. It did all these things and was a key to success in the Pacific. I just don't see how it compares to a P51 which appears to have a significant advantage over it! They are different fighters, produced with different criteria! In the time the hellcat was scoring significant victories in the Pacific the Luftwaffe was still a dangerous, very well organised force.

 

[Doughboy]

Hellcat.

 

[ironcat46]

What criteria do you use when comparing two very different aircraft? Appearance? A twin row Pratt Whitney 2800 radial engine vs. liquid cooled Rolls Royce? Hands down the Mustang was the looker. Top speed? Mustang. Climb rate? Hellcat. Durability? Hellcat. Combat proficiency? Hellcat. Why? A 19:1 kill ratio. Hellcats shot down 5163 enemy aircraft of all types with the loss of only 270 cats! The Mustang only achieved a 3.6:1 ratio. I suspect one reason the Mustang always out votes the competition is that it was the most produced American fighter of WW2, and it got its rep in the ETO (which for some reason was the more glamorous stage). Bottom line though is durability. Me thinks that over water be it the Pacific or Channel, the radial reliability of the Hellcat's Pratt Whitney (or a Jug's its ETO counterpart) would seal the deal for me. There were only about 4 thousand some odd more Mustangs produced than Hellcats during the war, but there were almost 10 times as many P-51's lost than F5F's!

 

[Doughboy]

What criteria do you use when comparing two very different aircraft? Appearance? A twin row Pratt Whitney 2800 radial engine vs. liquid cooled Rolls Royce? Hands down the Mustang was the looker. Top speed? Mustang. Climb rate? Hellcat. Durability? Hellcat. Combat proficiency? Hellcat. Why? A 19:1 kill ratio. Hellcats shot down 5163 enemy aircraft of all types with the loss of only 270 cats! The Mustang only achieved a 3.6:1 ratio. I suspect one reason the Mustang always out votes the competition is that it was the most produced American fighter of WW2, and it got its rep in the ETO (which for some reason was the more glamorous stage). Bottom line though is durability. Me thinks that over water be it the Pacific or Channel, the radial reliability of the Hellcat's Pratt Whitney (or a Jug's its ETO counterpart) would seal the deal for me. There were only about 4 thousand some odd more Mustangs produced than Hellcats during the war, but there were almost 10 times as many P-51's lost than F5F's!

You are correct.

 

[Doughboy]

Hellcat! It had the unbeatable 19:1 kill ratio and it proved to be one of the most succesful navy fighters.

 

[drgondog]

What criteria do you use when comparing two very different aircraft? Appearance? A twin row Pratt Whitney 2800 radial engine vs. liquid cooled Rolls Royce? Hands down the Mustang was the looker. Top speed? Mustang. Climb rate? Hellcat. Durability? Hellcat. Combat proficiency? Hellcat. Why? A 19:1 kill ratio. Hellcats shot down 5163 enemy aircraft of all types with the loss of only 270 cats! The Mustang only achieved a 3.6:1 ratio.

As a first time poster - I greet you. But I would like to take the time to request your sources and direct me specifically to your Macr rollup that leads you to believe any ratio you want people to believe. The 8th AF Mustangs, for example destroyed 3328 LW a/c in the air, 3212 on the ground, lost 326 in air to air combat, lost 570 strafing - and including losses air/ground lost a total of 1280 "all in" meaning
air
strafe
mechanical
weather
pilot/accident

The latter 3 ("other") categories were 1280 - 326-570 = 384

So, the ranking of cause of loss would be Strafing, Other, Air to Air combat

I suspect one reason the Mustang always out votes the competition is that it was the most produced American fighter of WW2, and it got its rep in the ETO (which for some reason was the more glamorous stage).

Who knows what your definition of Glamorous is - but Germany and the Luftwaffe was a threat to the world - Japan was not. Mustangs dribbled out to the PTO because the Strategic air mission over Germany was far more important than the Far East. The Luftwaffe was a far more formidable force than the IJN and IJA in any category you wish to look at except number of aircraft that flew off carriers.

Bottom line though is durability. Me thinks that over water be it the Pacific or Channel, the radial reliability of the Hellcat's Pratt Whitney (or a Jug's its ETO counterpart) would seal the deal for me. There were only about 4 thousand some odd more Mustangs produced than Hellcats during the war, but there were almost 10 times as many P-51's lost than F5F's!

I suspect, without proof that the F6F is more durable because of the radial and would have been a better ship strafing airfields - but I would point out that the Mustang lost fewer aircraft per strafing award than either the P-47 or the P-38.

You are comparing apples to oranges in both the Mission and the Competition.

A simple fact is that the Hellcat couldn't do what the Mustang did over Berlin and Poland and Czechoslovakia and Rumania and Austria - and the Mustang would never be carrier qualified by Navy brass.

I might also draw your attention to Henning's plots on the P-51D versus the F6F-5, which I have checked based on the flight test data. While we don't compeltely agree on some details (SL and altitude greater than Critical Performance altitudes are good) the trends and comparitive performance differences are pretty good.

I might also point out that the P-51B-5 with a Merlin 1650-3 or a P-51B-7 and -15 with the Merlin 1650-7 are all significantly better in climb and better in turn than the P-51D due to a.) better engine performance at high altitude for the -3 and about 500 pounds less take off weight than the P-51D.

My sources for the above statistics are;

USAF 85 (and Frank Olynyk's Stars and Bars) for cross reference of air Awards,
the 8th AF Victory Credits Board for Ground scores,
the Missing Aircrew Reports for 8th AF and,
the Accident Reports for the 8th AF

So, your sources would be?

So, in conclusion, present your Hellcat breakouts with sources so that we may learn from your academics.

Perhaps you and Doughboy can share data?

Regards,

Bill

 

[Watanbe]

If pilots of equal skill are fighting off in a Hellcat vs Mustang battle I would pick the Mustang every time. Its performance edge is to much to overcome, it has the ability to dictate how the fight proceeds!