Fulmar II versus F4F-4 under 10,000 ft.

[Shortround6]

While technically the Seafire MK III was the last one to see combat in WW II it might be interesting to compare when the MK III Seafire went into production and service with when the F4U-4 went into production and service.

For instance the F4U-4 first saw combat in May of 1945. As of August 1945 4 FAA squadrons were in the process of converting to the MK XV Seafire and some 250 or so of the Griffon engine planes had been built.

 

[parsifal]

SR yopu beat me to it...Mk XV had a top speed of 383 mph, whilst the Seafire 47 had a top speed of 456 mph. It was wrong of me to claim superior speed for the Seafire in the wartime context, but i was thinking of these post war developments. To set the record straight, theres no question in my mind that the Corsair was the best all round performer furing the war, but it was overtaken by the Seafire in the perior soon after the war.

As far as rate of climb, turn performance and general accelaration and all round performance below 5000 feet, i stand by my comments. The problem with the Seafire was not its performance, not even its reliability. Its problem was that its usefulness was too narrow. Aircraft like the Corsair could do a lot of different things, pretty good, the Seafire could do a few things very good, but most things only so so. thats why the Sea Fury was a much better propect post war.

 

[RCAFson]

From "Aircraft of WW2" by Kenneth Munson
Page 147 Supermarine Seafire (F.MkIII)-Max speed-352 mph at 12250 feet, service ceiling 33800 feet, normal range 465 miles, armament two 20mm cannon and four 303 Mgs, one 500 pound bomb or two 250 pound bombs optional

Page 50 F4U4 Corsair- Max speed 447 mph at 26000 feet, service ceiling 41000 feet, max range 1562 miles( normal from me, 1000miles), armament, six 50 cal Mgs, two 1000 pound bombs or eight RPs.

The F4U4 could do 380 mph at SL so was almost 30 mph faster at SL than was the Seafire at it's best altitude. The F4U had one of the best roll rates of any fighter in WW2, much better than any Spit or Seafire. The F4U carried enough ammo for 26.7 seconds of firing time, probably twice the firing time of the Seafire. One can argue all day about which plane was most heavily armed but the six fifties was more than adequate against Japanese fighters, bombers and kamakazes and the longer firing time was indispensable. So the Corsair in action during the last months of the war in the Pacific was almost 100 mph faster than the Seafire at best altitude and was faster at SL than the Seafire was at best altitude. It could fly higher and that Corsair could climb to 20000 feet in 6.8 minutes and had an initial rate of climb of 3870 fpm. The initial rate of climb of the Seafire IIC was 2950 fpm. I can't find the ROC of the III C.

So the Corsair could climb faster, was much faster in level speed, could get higher, carry a lot more bombs, a lot more ammo, roll better, was a lot more rugged( it could not be brought down by a single rifle caliber bullet in the cooling system) was built for carrier use at the outset and was more survivable in a ditching.

The only reason the RN continued to use Seafires after WW2 was that the Corsairs and Hellcats they had needed to be returned since they were lend leased.

Don't let nationalism stand in the way of common sense.

The F4U-4 did not enter combat until late May 1945 and when it did it could not meet the performance figures you state:

Max speed at SL was 303 knots or 349 mph.
Max speed = 443 mph at 29000ft
max climb at military rating = 3760 fpm at SL
Time to 20,000ft = aprox 7.8 mins with Mil power.
http://www.wwiiaircraftperformance.org/f4u/f4u-4-80765.pdf.
The above report notes that engine cooling was inadequate which maybe why they could not obtain more power.
The nearest equivalent Seafire was the Mk XV which was on its way to the Pacific when the war ended. It had:

max speed of 356mph at SL.
max speed = 395 mph at 14000ft (F4U-4 = 387mph at same altitude)
http://www.spitfireperformance.com/ns493.html (reported dated June 1944)
Max climb rate was 4340 fpm at 2000 ft. (From The Secret Years by Mason; RAE test report)
I would guesstimate about 5.5 to 6min to 20000ft at the combat rating.

The Seafire III entered service in late 1943.

 

[slaterat]

This has been a very informative thread. I have learned a lot about the Fairy Firefly and I'm impressed with its performance over Sumatra, something I will have to read up on. I haven't ever found much good reading on late war RN/FAA operations in the Pacific.

Regarding the initial topic of this thread, below 10,000 ft the Fulmar proved adequate as a fighter and was close to the performance of the F4F/Martlet and the Sea Hurricane. Above that height though the Fulmar is outperformed by both. Imho the Sea Hurricane is the best point defence/intercepter of the three, the Fulmar the most versatile and the best escort fighter, while the F4F/Martlet is capable of fulfilling both roles.

Slaterat

 

[slaterat]

If I had to pick one type to equip a carrier with I would have to pick the F4F/Martlet. The Fulmar's performance is too slow above 10,000 ft and the Sea Hurricane has too short of a range without drop tanks and lacks folding wings.

Slaterat

 

[parsifal]

I think that is a good assessment, but bear in mind the availability dates of the types. The Fulmar was operational before th F4f, but after 1941, justifying the Fulmar against the F4f becomes hard work

 

[fastmongrel]

Just been reading the performance chart posted by RCAFson very interesting but I am probably being stupid what does the acronym ACA mean

page 4 (1) Normal rated power
(a) max speed in level flight
(1) At ACA High blower

 

[renrich]

I don't care what you call me, just as long as you call me
Page 595, Dean, "America's Hundred Thousand" Graph 78B, F4U4 at 12420 pounds-380 mph TAS at SL at combat power.
Pge 594-"At very low altitudes the early Corsair was fastest at about 340 to 350 mph." That would be at military power. So the F4U1 was as fast or faster at SL as the later Seafire was at best altitude.
Page 596, Dean, and this is wise for all of us to understand:"One has to be very specific in talking about fighter maximum speed, being careful to define aircraft configuration, specific variant, altitude, weight condition and engine power setting as well as the condition of both airplane and engine."

Page 187, "Whistling Death," by Boone Guyton, main test pilot for the Corsair, " We began a series of engine cooling and carburetor tests, finally inching up to an incredible 75 inches MP. I approched this awesome power with due apprehension and vivid remembrance. The violence of those overheated, disintegrating engines, the crashes and the long hospital days were stark reminders of an earlier unpleasantness."" The trepidation was unwarranted. The new engine ran with satisfying smoothness at all power conditions-cause for celebration. Along with the second F4U-4X, No. 50301, which was soon ready for tests, performance data were obtained that exceeded estimates. Top speed was now 450 mph at 26600 feet, versus the F4U1D's 425 mph at 20000 feet. Rate of climb was extended to almost 4000 feet per minute from 3100 feet per minute."

The Corsair was also an excellent diving airplane and very stable in dive, undoubtedly a better diver than any Spitfire variant. The interesting thing about the Corsair was that as the airplane evolved each new model was a nicer handling airplane. This was not often true with other WW2 fighters. An example would be the P51, where the early Allison powered model was considered a much nicer handling aiplane than the later P51D.

Back to the armament issue. If the 20 mms are the determinant, the F4U1C and the F4U4B were armed with four 20 mms with 225 rounds of ammo for each gun. The later F4U5 was exclusively armed with the four 20 mms and it could reach 465 to 470 mph at critical altitude.

The fact remains though that the Allies achieved air supremacy in WW2 over Germany and Japan, predominately with US fighters armed with the 50 BMG.

 

[tomo pauk]

The fact remains though that the Allies achieved air supremacy in WW2 over Germany and Japan, predominately with US fighters armed with the 50 BMG.

Air supremacy over Germany Japan was a product of the hard work sacrifice by many allied AFs efforts.

 

[RCAFson]

Just been reading the performance chart posted by RCAFson very interesting but I am probably being stupid what does the acronym ACA mean

page 4 (1) Normal rated power
(a) max speed in level flight
(1) At ACA High blower

ACA = Airplane Critical Altitude, which is equivalent to the Commonwealth FTH or Full Throttle height

 

[renrich]

No question that the air war was won by an overall effort of all the arms of all the Allies. Army, Navy, Air Force. I meant however that when the war was nearing it's end the Allied aircraft that roamed the skies over Germany and Japan were predominately US AC armed with the 50 BMG. Most of the Japanese aircraft shot down by Allied aircraft in WW2 were shot down by AC armed with the 50 BMG. The daylight precision bombing of the AAF was enabled by Mustangs with either four or six 50 BMGs. The Mustangs and Thunderbolts that roamed the skies of Germany in 44-45 were in the majority and were armed with the 50 BMG. Perhaps the US fighters would have been more effective with cannon, perhaps not but the fact remains. They got the job done.

 

[RCAFson]

I don't care what you call me, just as long as you call me
Page 595, Dean, "America's Hundred Thousand" Graph 78B, F4U4 at 12420 pounds-380 mph TAS at SL at combat power.
Pge 594-"At very low altitudes the early Corsair was fastest at about 340 to 350 mph." That would be at military power. So the F4U1 was as fast or faster at SL as the later Seafire was at best altitude.
Page 596, Dean, and this is wise for all of us to understand:"One has to be very specific in talking about fighter maximum speed, being careful to define aircraft configuration, specific variant, altitude, weight condition and engine power setting as well as the condition of both airplane and engine."

Page 187, "Whistling Death," by Boone Guyton, main test pilot for the Corsair, " We began a series of engine cooling and carburetor tests, finally inching up to an incredible 75 inches MP. I approched this awesome power with due apprehension and vivid remembrance. The violence of those overheated, disintegrating engines, the crashes and the long hospital days were stark reminders of an earlier unpleasantness."" The trepidation was unwarranted. The new engine ran with satisfying smoothness at all power conditions-cause for celebration. Along with the second F4U-4X, No. 50301, which was soon ready for tests, performance data were obtained that exceeded estimates. Top speed was now 450 mph at 26600 feet, versus the F4U1D's 425 mph at 20000 feet. Rate of climb was extended to almost 4000 feet per minute from 3100 feet per minute."

The Corsair was also an excellent diving airplane and very stable in dive, undoubtedly a better diver than any Spitfire variant. The interesting thing about the Corsair was that as the airplane evolved each new model was a nicer handling airplane. This was not often true with other WW2 fighters. An example would be the P51, where the early Allison powered model was considered a much nicer handling aiplane than the later P51D.

Back to the armament issue. If the 20 mms are the determinant, the F4U1C and the F4U4B were armed with four 20 mms with 225 rounds of ammo for each gun. The later F4U5 was exclusively armed with the four 20 mms and it could reach 465 to 470 mph at critical altitude.

The fact remains though that the Allies achieved air supremacy in WW2 over Germany and Japan, predominately with US fighters armed with the 50 BMG.

Trying to unravel the mystery of F4U-1/4 performance isn't easy. The wartime F4U-4 used the R2800-18w engine, but post war variants were fitted with the more powerful R2800-42w.

The F4U-1/4 only had 10- 13.5 usgals of water for injection, which, AFAIK was only good for 5 - 6 minutes before exhaustion. So, unlike overboost on the Merlin or Griffon. 6 minutes was the limit for WEP on the F4U with WI, and if exceeded the engine would self destruct in very short order, with almost certain loss of the aircraft. The R1800-18w aircraft used 115/145 octane fuel as well. So the performance claims of the F4U-1/4 on WI are very misleading since there is a hard limit on how long the engine can run at these powers, rather than an advisory notice on the Merlin/Griffon, that could be, and often was ignored in combat, and could be used repeatedly on a single sortie, even within the 5 minute advisory limit.

Also, AFAIK the Spitfire (and probably the Seafire) had the highest limiting mach number of any WW2 aircraft and would be able to outdive almost any WW2 aircraft.

 

[Jabberwocky]

It took significant changes to the landing gear struts to make the Seafire acceptable - just barely - for carrier operations

In what respects was it "just barely" adequate. What is your basis for a statement like that. Please table information that shows it to be "Just barely" adequate. In fact, if you research the issue even a little, you will find the British viewed it as essential in their integrated defence arrangements. It was by far the best CAP aircraft that they possessed below 5000 feet, which is where it mattered against the Kamikazes, and by far the most important weapon system available to the BPF in its battle against this threat.

Response on landing gear to come in a few hours. I've got some interesting RN pilot commentary on the Seafire's landing tendencies, all the way up to the Mk 47.

In what respects was the Corsair "not in the same league?"

In the sense of having far superior climb , far heavier and effective armament (20mm are acknowledged by all except those diehard Americans who think 6x 50s are better than anything except 8 x 50s) higher accelaration and better speed below 5000 ft. Turn radius was better as well. "Not in the same league" is not the same as trying to say "superior to"...more "better at certtain things"....


Speed, turn performance, range, armament, combat load?

Sppeed below 5000 ft was superiuor in the Seafire, turn performance far superior in the Seafire, armament was far heavier in the Seafire (though I will never have that acknowledged I know, but its a fact, I assure you) , range was superior in the Corsair, but not greatly so, if effctive combat radii are being talked about, combat load, well, the Corsair had it all over the Seafire in that regard.

Wartime Seafires of all stripes (Merlin engines) were outpaced by contemporary Corsair's all the way from sea level through to 30,000 ft. Typical advantage was in the region of 20-30 mph at any given height until the post-war Griffon Mks.

RoC was only better in Seafires with engines tuned for low altitude performance, although it was significantly better in the L Mk III. Even then, climb superiority disappeared over 14,000 feet compared to Corsairs. RN Corsairs fitted with water injection were generally better above 10,000 ft in RoC.

Seafires were anywhere from 1 minute to 5 minutes quicker to 20,000 ft than contemporary Mks of Corsair. Typically a Seafire took 8-9 minutes to get to 20,000 ft, a Corsair to 10-13

Low alt turn performance may not have been as good in the Corsair, but the aircraft was increasingly competitive as altitude increased. The Corsair had better roll performance than the Seafire, as was its dive and zoom performance.

Maneuverability is not just about turn radius - witness the 1942 Channel front battles.

As for range, according to RN data sheets range in a Corsair Mk I was 25% better on internal fuel and 33% better with overload D/Ts than a Seafire Mk III - the longest ranged of the Seafires

Corsair Mk II had a 65% advantage on internal fuel, and a 105% range advantage with overload D/Ts.

Spitfires were significantly bettered by the Zero over Darwin... losing out at a rate of about 3:1

And this is different to the Corsair in what respects????? In their first encounters with zeroes they lost about twice as many of their number as the zeroes lost. The Spits over Darwin used the wrong tacticws, lost more aircraft to running out of fuel, and overall were poorly used. their combat records are not that much worse than other types like the P-40 at the time and in any event, the defence at Darwin was a difficult target to defend. To say nothing of comparing apples to oranges

Actually, the recently published 'Darwin Spitfires' by A.Cooper, the P-40 was only slightly bested by the Zero in the defence of Darwin in fighter v fighter engagements, about 1.1-1.2:1. On the other hand, the Spitfires of the RAAF and RAF - excluding mechanical and fuel related losses - still lost out in fighter v fighter combat by about 3:1

I don't have any Zero vs Corsair loss stats to hand. The USN really lies outside my sphere of interest

 

[renrich]

I have reported on this before so will not bother to copy the entire quote from Boone Guyton's book. During the Fighter Conference in January, 1944, Guyton did a simulated-combat against Ken Walsh, a Marine Ace in the Corsair. Guyton was in the latest production F4U1 with a 60 GALLON WING WATER TANK(my caps) and Walsh was in a brand new F3A with a tank of only 10.3 gallons. So you see there were some Corsairs with more than ten gallons of water. Incidently, Guyton with more hours in a Corsair than anyone in the world and a former Navy pilot was strummed by Walsh three times.

Diving ability refers to the ability of the airplane to go into a dive quickly and pick up speed quickly, not the limiting Mach number. Bob Johnson in his book mentions in his mock dogfights with Spitfires that the Spitfire could not dive quickly or fast compared to his Thunderbolt and he used that to win those exercises. His tactics were, if a Spit was on his tail, to begin to roll violently left and right. The Spit could not stay in the same plane with him while rolling. Then he would roll into a dive and the P47 would rapidly pull away from the Spit. The Spit from level flight could outclimb the early P47 but after picking up much speed in a dive the P47 would zoom climb and leave the Spit far behind, stuggling to catch up. At the top of the P47's zoom climb, Johnson would hammerhead stall the Jug and suddenly the Spit would find himself confronting head on a P47 with eight fifties pointing at him. The Corsair could almost pick up speed in a dive as fast as the Jug and was very stable in that dive(no constant retrimming.)

 

[RCAFson]

I have reported on this before so will not bother to copy the entire quote from Boone Guyton's book. During the Fighter Conference in January, 1944, Guyton did a simulated-combat against Ken Walsh, a Marine Ace in the Corsair. Guyton was in the latest production F4U1 with a 60 GALLON WING WATER TANK(my caps) and Walsh was in a brand new F3A with a tank of only 10.3 gallons. So you see there were some Corsairs with more than ten gallons of water. Incidently, Guyton with more hours in a Corsair than anyone in the world and a former Navy pilot was strummed by Walsh three times.

Diving ability refers to the ability of the airplane to go into a dive quickly and pick up speed quickly, not the limiting Mach number. Bob Johnson in his book mentions in his mock dogfights with Spitfires that the Spitfire could not dive quickly or fast compared to his Thunderbolt and he used that to win those exercises. His tactics were, if a Spit was on his tail, to begin to roll violently left and right. The Spit could not stay in the same plane with him while rolling. Then he would roll into a dive and the P47 would rapidly pull away from the Spit. The Spit from level flight could outclimb the early P47 but after picking up much speed in a dive the P47 would zoom climb and leave the Spit far behind, stuggling to catch up. At the top of the P47's zoom climb, Johnson would hammerhead stall the Jug and suddenly the Spit would find himself confronting head on a P47 with eight fifties pointing at him. The Corsair could almost pick up speed in a dive as fast as the Jug and was very stable in that dive(no constant retrimming.)

I suspect Guyton was flying a factory modded F4U with an increased WI tank, to facilitate testing. Both the F4U-1D and F4U-4 detail specs state 10/13.5 gallons:
http://www.wwiiaircraftperformance.org/f4u/f4u-1d-detail-specification.pdf
http://www.wwiiaircraftperformance.org/f4u/f4u-1d-detail-specification.pdf
which would give both the same time for WEP, given the greater consumption of the 2800-18.

No doubt a Thunderbolt had an edge in dive over a Spit V, but the late mark Seafires were heavier and more powerful (over the Spit v), especially in combat where the pilots could use overboost freely. I really doubt that diving away from a Seafire XV, for example would have been a successful tactic, especially given its superior power to weight ratio and if the Seafire forced the F4U to use up its WI, then the F4U would be at a severe disadvantage. I don't think that any Seafires had clipped wings, but this could have been done to increase the roll rate, if it was felt to be necessary.

 

[Juha]

IMHO Spitfires/Seafires were not great diver, they did not pick up speed as fast as some of the heavier fighters, for ex P-47. Of course in long deep dives Spit didn't run to compression problems easily because of its critical Mach number was very high for a WWII plane thanks to its very thin wing, again contrary to P-47 and P-38, both of which had low critical Mach number for WWII fighter.

As airplane Seafire LIII handled very well, as one can read from Corky Mayer's (Grumman's test pilot) writings. He was almost in ecstasy after his first flight in it, probably just at Fighter Meeting 1944.

Juha

 

[Kryten]

you have to bear in mind the seafire was an adaption to carrier operations not designed for it like the planes it is being compared to, thats bound to create shortcomings, but as a fleet defence fighter it was without doubt very good and if you had to choose a fighter for that role it was a good option, for the fighter bomber role however the heavier carrier types would be a perferred option I would have thought!!

 

[renrich]

The fact remains though that no WW2 Seafire was as fast or faster than even the F6F3 or especially the F6F5. Speed was important when acting as a CAP for the fleet, expecially against Kamikazes. Many Kamikazes were fighters with a bomb attached and they could get to the target a lot faster than VBs or VTs so the CAP needed to have all the speed they could muster. That is why the USN issued the mandate to replace all VFs in the fleet with the Corsair because it had a significant edge in Vmax over the Hellcats. Range was important in a CAP as well as ammo capacity. The CAP being refueled or rearmed on the deck was not doing any good. The IJN experienced this at Midway because the cannon in the A6Ms at that time only carried 90 rounds per gun and the rifle caliber weapons mounted over the engine were not very effective against the US attackers. Consequently the A6Ms kept the flight decks of the IJN carriers tied up during the US attacks being rearmed even though the IJN VFs had very good endurance. The Seafires had good climb and good firepower but not good endurance, not a lot of firing time and were a little deficient in Vmax, much like the Hellcat. The Spitfire was, in 1940 and even later, a fine interceptor, especially against he LW and in ACM at least held it's own against the BF109. The Spit and BF109 were similar AC, small, short ranged, maneuverable, good firepower for that time, fast climbers but not particularly resistant to battle damage. Neither were designed as shipboard aircraft though. As great a design as the P51 was it would not have made a good shipboard fighter. It probably would have been better than the F4F if it had been adapted for shipboard use but would have been lacking compared to the Hellcat and Corsair.

 

[renrich]

Here are some interesting "facts" or statistics about fighters operating off of carriers in WW2.
Navy Hellcats flew 62240 action sorties from US carriers in WW2
Hellcats flying from carriers were credited with 1387 bombers and 3568 fighters shot down.
If you divide the total number of planes credited with the number of sorties, then you get .08 kills per sortie
Navy Corsairs flew 6488 action sorties from carriers during WW2
Navy Corsairs were credited with 100 bombers and 260 fighters when flying from carriers which gives .06 kills per sortie.
without doing the numbers it looks like the ratio of bomber to fighter kills is about the same so the Hellcat looks a little more lethal than the Corsair
But Marines flew 3093 action sorties from carriers in Corsairs in WW2
Marines flying from carriers were credited with 59 bombers and 159 fighters which gives .07 kills per sortie.
So Marine pilots in Corsairs were a little more lethal than Navy pilots in Corsairs but not as lethal as Navy pilots in Hellcats. At least that is what the statistics say.

Points to consider:
Hellcats got a lot of kills during the Marianas Turkey Shoot and in other carrier versus carrier battles when some of the IJN pilots were barely carrier qualified.
Most or all of the carrier based Corsair kills were against land based attackers.
Were Zekes or other VFs carrying a bomb in the Kamikaze attacks considered a bomber or fighter.
During the last months of the war, Navy fighters were going up against very late model Japanese fighters.
Many of the Marine fighter kills were off of CVEs.
Many of the Kamikaze pilots were low time pilots

My conclusion is that you cannot draw many very accurate conclusions from these "Facts"

 

[RCAFson]

The fact remains though that no WW2 Seafire was as fast or faster than even the F6F3 or especially the F6F5. Speed was important when acting as a CAP for the fleet, expecially against Kamikazes. Many Kamikazes were fighters with a bomb attached and they could get to the target a lot faster than VBs or VTs so the CAP needed to have all the speed they could muster. That is why the USN issued the mandate to replace all VFs in the fleet with the Corsair because it had a significant edge in Vmax over the Hellcats. Range was important in a CAP as well as ammo capacity. The CAP being refueled or rearmed on the deck was not doing any good. The IJN experienced this at Midway because the cannon in the A6Ms at that time only carried 90 rounds per gun and the rifle caliber weapons mounted over the engine were not very effective against the US attackers. Consequently the A6Ms kept the flight decks of the IJN carriers tied up during the US attacks being rearmed even though the IJN VFs had very good endurance. The Seafires had good climb and good firepower but not good endurance, not a lot of firing time and were a little deficient in Vmax, much like the Hellcat. The Spitfire was, in 1940 and even later, a fine interceptor, especially against he LW and in ACM at least held it's own against the BF109. The Spit and BF109 were similar AC, small, short ranged, maneuverable, good firepower for that time, fast climbers but not particularly resistant to battle damage. Neither were designed as shipboard aircraft though. As great a design as the P51 was it would not have made a good shipboard fighter. It probably would have been better than the F4F if it had been adapted for shipboard use but would have been lacking compared to the Hellcat and Corsair.

The Mk XV was a WW2 variant, but it is a lot longer from the UK to Japan, than from the USA, and it never saw combat. The RN was fighting "kamikaze" attacks in the form of Luftwaffe FW-190 tip and run attacks from mid 1943, and as a result Seafires were highly optimized for low altitude performance, and a high climb rate to allow successful intercepts and altitude superiority for high speed diving attacks. The loiter times of the Seafire with its SS drop tank is not far off the Hellcat on internal fuel:

The Seafire III was produced in medium and low altitude versions which had similar range and performance to the LIIC:
http://www.spitfireperformance.com/lf3.jpg