F4U vs. P-51 essay

[renrich]

Comparing the P51 versus the F4U is great fun. I have participated in that exercise many times. Both were premier AC in WW2. The P51 has had the best PR agent, whoever that is, because according to popular thinking it was the best fighter in WW2. However comparing the Corsair to the Mustang is kind of like comparing the Morgan horse to a Thoroughbred. Depends on what you are needing it for. If you are going on a race track with a jockey you want a Thoroughbred, if you are going harness racing you want a Morgan. If you want a fighter bomber you want a Corsair, if you want an escort fighter, you want a Mustang. They are both somewhat interchangeable but they both have their strong points. On balance if only one fighter could have been produced in WW2 by the US, it would have to be the Corsair because of it's carrier capability. To have made the Mustang truly carrier capable much of it's performance would have been lost. On top of that the Navy would have turned it down because of the liquid cooled engine.

 

[davparlr]

Comparing the P51 versus the F4U is great fun. I have participated in that exercise many times. Both were premier AC in WW2. The P51 has had the best PR agent, whoever that is, because according to popular thinking it was the best fighter in WW2. However comparing the Corsair to the Mustang is kind of like comparing the Morgan horse to a Thoroughbred. Depends on what you are needing it for. If you are going on a race track with a jockey you want a Thoroughbred, if you are going harness racing you want a Morgan. If you want a fighter bomber you want a Corsair, if you want an escort fighter, you want a Mustang. They are both somewhat interchangeable but they both have their strong points. On balance if only one fighter could have been produced in WW2 by the US, it would have to be the Corsair because of it's carrier capability. To have made the Mustang truly carrier capable much of it's performance would have been lost. On top of that the Navy would have turned it down because of the liquid cooled engine.

Very astute observation. I agree completely.

 

[Sgt. Pappy]

in terms of how the F4U would perform in the ETO and MTO, I think it would have performed somewhat like the P-38/47 did in terms of success.

In the PTO, the F4U and P-38 were the top notch aircraft of their respective Corps but in the ETO, the P-38 sorta died... flew improperly. It was maneuvered more with impulse than technique. In the MTO, its unparalleled zoom, dive and acceleration were used to a good extent to fight. In the MTO during escort missions, especially early on, the P-38F, G, and to some extent the H variants really did not compare well to the quick climbing/accelerating German aircraft.

In the PTO, the P-38 had all the speed, climb and high altitude performance. The F4U, being used mostly as a BnZ role in the PTO, would not have been able to fight the 109's (particularly the 109's) while the other extremely fast hot rod aircraft like the P-51 or well turning planes like the Spitfire could fight the 109's more easily. If anything, the Corsair would have been similar in fighting performance to the P-47. Neither of the planes had the best climb/acceleration in the world, but the P-47 dove well and was tough as tungsten nails. The Corsair, was more maneuverable than the P-51 or P-47 and though couldn't turn as fast as the P-38, could turn much tighter.

The F4U was tricky to fly and stalled nastily while the P-38 had very difficult systems to manage. But being similar in performance to the P-47, yet arguably harder to fly, I've come to conclude that an F4U would perform like a P-38/47, though it would likely be sent for Hurricane-like ground attack missions, with the ability, to some extent, perform Spitfire-esque defense missions since its high-altitude performance does not parallel that of either the turbo-charged P-38/47.

 

[renrich]

One of the problems with comparing different AC, especially the premier fighters, P51, P47, P38, F4U, F6F, Fw 190 and BF109(maybe a few others) is that the airplanes evolved during the war and the different models were optimized for various missions. P47B and C were range limited, P47N had good range. P51B had good performance, problematical armament, poor visibility. The P51D had slightly less performance but much better in the other factors. Early F4U1s had poor visibility, carrier landing problems, nasty stall characteristics, etc. Later F4Us largely solved all those problems. Additionally, AC were tailored for specific types of missions. FW190s early on had good performance down low, not so good up high. A BF109 with two mgs and one cannon was an agile dogfighter. A BF109 with gondolas and many cannon was good against bombers, not so good in a dogfight. F4U1D was optimized for the fighter bomber role. F4U4 could still do the fighter bomber deal but was really fitted for knocking down kamikazes high and low. The Navy fighters were not optimized for high altitude performance because the ships they were protecting were literally at sea level and high altitude bombers were not much of a threat. It was no accident that the fastest premier US fighter at sea level in WW2 was probably the F4U4. The point here is that to say this AC or that airplane was superior to another needs to be qualified by defining the mission the airplane is meant to carry out. A 1945 version P47N with its wings full of fuel and a full ammo load might be uncomfortable low and slow against an old A6M5. One misconception I believe is that Navy fighters could not fight at high altitudes. They weren't optimised for that but a Corsair( it was not a F4U4 because it had a 3 blade prop) caught a Dinah recon plane over Okinawa at 38000 ft and because his guns were frozen made several runs and chewed off the Dinah's tail with his prop. That shows that it could fight at high altitudes and it had enough performance to catch up more than once.

 

[syscom3]

"..It was maneuvered more with impulse than technique....."

"...while the P-38 had very difficult systems to manage....."

What did that mean?

 

[drgondog]

in terms of how the F4U would perform in the ETO and MTO, I think it would have performed somewhat like the P-38/47 did in terms of success.

As it was in general, more agile than both and had a greater range than the contemporary models of the P47C and D - it probably would have done very well indeed

In the PTO, the F4U and P-38 were the top notch aircraft of their respective Corps but in the ETO, the P-38 sorta died... flew improperly. It was maneuvered more with impulse than technique. In the MTO, its unparalleled zoom, dive and acceleration were used to a good extent to fight. In the MTO during escort missions, especially early on, the P-38F, G, and to some extent the H variants really did not compare well to the quick climbing/accelerating German aircraft.

On the other hand the P-38L solved all the previous operational problems except compressibility w/o dive brakes... and the dive brakes enabled excellent div control, albeit at slower speeds than the others in comparison.

In the PTO, the P-38 had all the speed, climb and high altitude performance. The F4U, being used mostly as a BnZ role in the PTO, would not have been able to fight the 109's (particularly the 109's) while the other extremely fast hot rod aircraft like the P-51 or well turning planes like the Spitfire could fight the 109's more easily. If anything, the Corsair would have been similar in fighting performance to the P-47. Neither of the planes had the best climb/acceleration in the world, but the P-47 dove well and was tough as tungsten nails. The Corsair, was more maneuverable than the P-51 or P-47 and though couldn't turn as fast as the P-38, could turn much tighter.

??? the F4U was as good or slightly better Model for Model as the P-51, turned tighter than both the P-47 and P-38 and accelerated sligtly faster depending on the altitude than the Mustang. Until above 25,000 feet the choice between and F4U and Mustang would have been personal choice - not clear cut superiority between either

The F4U was tricky to fly and stalled nastily while the P-38 had very difficult systems to manage. But being similar in performance to the P-47, yet arguably harder to fly, I've come to conclude that an F4U would perform like a P-38/47, though it would likely be sent for Hurricane-like ground attack missions, with the ability, to some extent, perform Spitfire-esque defense missions since its high-altitude performance does not parallel that of either the turbo-charged P-38/47.

At the altitudes of interest, namely 30,000 feet and below where top cover for escorted bombers was conducted, the F4U performed very well in comparison to all of the prime ETO fighters. The F4U-4 was slower at 30,000 feet than the P-51B/D and P-47D but at the end of the day, would have outperformed both the Fw 190A and Me 109G's in the same areas a Mustang did.

The Me 109G would have climbed better in a tight climbing turn and the Fw 190 would have outrolled it below 350 mph (or thereabouts). I suspect the F4U-4 would have been a slightly better dogfighter than the Mustang below 15,000 feet and better than all the P-47D's

 

[fjray]

Good job with the essay!

I'll throw out something on comparisons. Flying an aircraft vs fighting with it. An aircraft may be great to fly but how is it to fight with? For an example the Mustang by all accounts was a joy to fly. However with a full bag of gas in the internal tank it was more difficult to handle in a dogfight.

Of course I'm still partial to the Hellcat 8)

 

[magnocain]

Thanks guys!

I also wanted to cause some controversy and alternate opinions, as I am the most informed person I have met.

 

[kool kitty89]

The P-47D was longer ranged than many realize, The P-47D-25 (65 gal increased internal capacity over earlier models) could manage 2,100 mi with 780 US gallons at 206 mph. (this was with 2x 150 gal wing tanks and a 110 gal belly tank)

But with the P-47C and many early D models, wing pylons and plumbing were not fitted and the max external fuel load was with a 200 gal conformal laminated paper drop tank on the belly. (which was not used once wing tanks were available since it was unpressurized and dangerous to land with, though a 200 gal steel belly tank was used late in the war and the Pacific P-47s had custom made "big and ugly" 200 gal wing tanks) With the 200 gal tank plus the 305 gal internal the P-47 could manage but 1,400 mi, similar to the P-40 with drop tank of the same time.

Pacific P-47's also used 165 gal P-38 tanks as wing tanks. (note belly tank capasity was limited due to clearance not weight issues, hence why large flat tubs were used for high capacities -otherwise a 75 or 110 gal tank is all it could hold)

see: http://www.wwiiaircraftperformance.org/p-47/p-47-tactical-chart.jpg

However, I don't have figures for the F4U.

 

[syscom3]

I also wanted to cause some controversy and alternate opinions, as I am the most informed person I have met.

 

[renrich]

KK those ranges you quote for the P47 are, I believe, "yardstick" ranges, not really practical ranges. My reference says the late model Ds with a max of 780 gals could get about 1800 miles. However, that is based on a 10000 foot cruise altitude, zero wind, no fuel reserve, no takeoff,, no climbout or descent and of course no combat. A practical range would be more like 70% of the "yardstick" range. A P47D combat radius with 670 gal. of fuel would be about 670 miles. The mission profile would be: 5 min fuel for warmup and takeoff: climb to 25000 feet(distance not included)cruise at 25000 feet; drop tanks; 5 min @ combat power; 15 min at military power; cruise back at 25000 feet; fuel reserves 30 min at minimum cruise power. The early F4U1s with internal fuel of 361 gallons could get a "yardstick" range of slightly more than 1500 miles. A contemporary P47C or early D with 305 gallons internal fuel could get around 835 miles "Yardstick"

 

[Sgt. Pappy]

"..It was maneuvered more with impulse than technique....."

"...while the P-38 had very difficult systems to manage....."

What did that mean?

It means that the P-38 wasn't as skillfully flown in the ETO overall as the P-38 Training programs were better for those in the PTO, for example.

The early P-38's which did much of the initial escort work, did not have the best engine management systems. Flying on cruise settings and suddenly throttling up while still at a coarse prop pitch would likely result in engine fire.Before the advent of the P-38H, come cooling instruments were not automatic and pilots were given a larger workload and before the advent of the P-38J, cooling the engines and flying at maximum performance could nto be afforded in the same sentence.

 

[kool kitty89]

But under those same conditions (and the same trial sheets) the P-38J had a maximum range of ~2,260 mi (with 300 gal drop-tanks) while the P-51D had 1,800 mi (with 75 gal drop tanks, although another 800 mi could be achieved with 2x 150 gal drops in the P-51B but those were not listed for the D model) And the P-47's range didn't decrease with altitude, endurance did though. (higher cruising speed) In both the P-47 and P-38 range at max cruise power increased slightly with altitude, but with the P-51 it decreased. (probably a result of turbocharging vs supercharging)

See: http://www.wwiiaircraftperformance.org/mustang/p-51-tactical-chart.jpg
http://www.wwiiaircraftperformance.org/p-38/p-38-tactical-chart.jpg
http://www.wwiiaircraftperformance.org/p-47/p-47-tactical-chart.jpg

 

[drgondog]

But under those same conditions (and the same trial sheets) the P-38J had a maximum range of ~2,260 mi (with 300 gal drop-tanks) while the P-51D had 1,800 mi (with 75 gal drop tanks, although another 800 mi could be achieved with 2x 150 gal drops in the P-51B but those were not listed for the D model) And the P-47's range didn't decrease with altitude, endurance did though. (higher cruising speed) In both the P-47 and P-38 range at max cruise power increased slightly with altitude, but with the P-51 it decreased. (probably a result of turbocharging vs supercharging)

See: http://www.wwiiaircraftperformance.org/mustang/p-51-tactical-chart.jpg
http://www.wwiiaircraftperformance.org/p-38/p-38-tactical-chart.jpg
http://www.wwiiaircraftperformance.org/p-47/p-47-tactical-chart.jpg

The Ferry range for the B/C/D was essentially the same with two 110 gallon tanks = 2120 miles. The ferry range for the P-51H was 2230miles and max ferry range for the H was 2900 miles with two 165 gallon tanks

From Gruenhagen's Mustang" book. I haven't seen better sources yet

As to cruise altitude, speed, rpm and boost- all aircraft, in general and even with the exact same engine and weights, had a different cruise altitude for max range - and all suffered on either side of that altitude, boost settings RPM, etc.

If the aerodynamics were the same for lift and drag then they would be close to each other.

KK - what do you have for P-38L settings for maximum Ferry range? I haven't seen them

 

[syscom3]

It means that the P-38 wasn't as skillfully flown in the ETO overall as the P-38 Training programs were better for those in the PTO, for example.

The early P-38's which did much of the initial escort work, did not have the best engine management systems. Flying on cruise settings and suddenly throttling up while still at a coarse prop pitch would likely result in engine fire.Before the advent of the P-38H, come cooling instruments were not automatic and pilots were given a larger workload and before the advent of the P-38J, cooling the engines and flying at maximum performance could nto be afforded in the same sentence.

The P38's escorting the B17's were restricted to close escort duties, which hamstrung the pilots ability to hunt down and kill the LW.

The P38 engine issues in western Europe has been discussed numerous times.

 

[drgondog]

The P38's escorting the B17's were restricted to close escort duties, which hamstrung the pilots ability to hunt down and kill the LW.

The P38 engine issues in western Europe has been discussed numerous times.

Syscom - strictly speaking, All 8th FC escorts were flying close escort until Doolitle turned the dogs loose on or about 11 January, 1944... after that point several fighter groups, notably the 356th and 78th didn't noticably change their 'stick close' escort tactics until later. On the other extreme, the 4th took it to heart.

From the microfilm histories it seemed the 2oth and 55th were in the middle on 'aggressive pursuit'.

I think the bigger factor on the low air to air performance for the P-38 groups in ETO is that they were easy for LW fighters to spot - and therefore avoid.

Then you fast forward to Zemke taking over the 479th and see an amazing transformation of ratios. OTH the attrition on LW 'old hands' had was serioue by August so even then it's hard to compare results against Jan-April 1944.

 

[syscom3]

Syscom - strictly speaking, All 8th FC escorts were flying close escort until Doolitle turned the dogs loose on or about 11 January, 1944... after that point several fighter groups, notably the 356th and 78th didn't noticably change their 'stick close' escort tactics until later. On the other extreme, the 4th took it to heart.

Many squadrons were told to stick close to the bombers because of its easy to recognize shape.

 

[drgondog]

Many squadrons were told to stick close to the bombers because of its easy to recognize shape.

True for all 8th FC fighters before the "seek out the Luftwaffe on the air and the ground" directive from Doolittle.

Actually it was SOP to stay out of range of the bombers as they had an inclination to shoot at anything with less than 4 engines.

More important to the P-38 ability to engage LW is that a.) they were so large it was easy to spot them before being spotted, and b.) given their detection the LW, which was issued orders 'to avoid the fighters', then looked for easier pickings.

 

[Sgt. Pappy]

The P38's escorting the B17's were restricted to close escort duties, which hamstrung the pilots ability to hunt down and kill the LW.

The P38 engine issues in western Europe has been discussed numerous times.

I'm sure these and the factors I mentioned all came up to hinder the P-38's performance in the ETO. This is unfortunate because the P-38 was a wonderful plane...
and it wasn't the only plane to initially fail in a Theater. Little do people know about the Spitfire's sub-par performance with the RAAF in the PTO. Huge amounts of mechanical problems, poor air-air strategies and lack of spare parts spelled near-doom for the RAAF during the first half of 1943. The Japanese eventually retreated from attacks on Australia due to the US forces attacking Guadalcanal. The RAAF only received a superlative Spitfire VIII when the Japanese raids had ceased.

The P-38L in Europe entered service when the P-51's gun jamming bugs had been solved and after the cheaper P-51D had been built in large enough numbers. By this time, as mentioned, new escort tactics were adopted and the situation improved from there.

 

[kool kitty89]

I've seen ~3,300 mi for the P-38L's ferry range but no sourse. I also don't have figures for the F4U. Acording to those tables the P-51B with increased internal tankage (added tank behind pilot) could manage 2,600 mi ferry with 2x 150 gal drop tanks.

From what I've seen the P-47 a similar range is possible to the P-51 in most cases, but the P-47 needs ~50% more fuel to do so.

Without wing tanks the P-47 (B/C/earlyD all had same internal capacity and no wing pilons standard) could manage a maximum of 1,400 mi with the 200 gal paper ferry tank. This tank was not used once wing pylons wae fitted as it provided little clearance, was unpressurized, and was too fragile to land with.

From what I've read the droppable tanks that could be used on the P-47 were, in US gallons:
The 200 gal conformal paper belly tank used as an intrim measure in 1943, the 75 gall steel teardrop tank used on belly and wings, the 110 gal paper tank used on belly or wings, 150 gal tanks used on wings only, 165 gal P-38 tanks used in the Pacific as wing tanks, 200 gal steel wing tanks developed and used in the pacific, a 215 gal flat tub-shaped steel belly tank used in early 1945.

315 gal wing tanks were used on the P-47N iirc.

The main limiting factor for belly tanks was ground clearance so large capacities were possible only if the tanks were realitively flat. Otherwise the largest capacity was the 110 gal British paper tank. (as the 200 gal paper tank abandoned early on)