F6F Top Speed

[joeblogs]

Bodhi -

According to P&W documents you're right. I think a Navy SEFC chart I was looking at mislabels a -18w for a -8W. The former is optimized for higher altitudes...

-blogs

Originally posted by Bodhi
The ONLY difference between the -8 and -10 is the downdraft carburetor on the -10.  That is it.

[Bodhi]

Originally posted by joeblogs
Bodhi -

According to P&W documents you're right. I think a Navy SEFC chart I was looking at mislabels a -18w for a -8W. The former is optimized for higher altitudes...

-blogs

The Navy mislabels a lot of things...

[Widewing]

Originally posted by Bodhi
Production -5 Hellcats DID NOT see fleet service with 20mm cannon.  The only reason the wing is configured both ways is for ease of manufacture, as Grumman did not to completely tool up two assemblies of the wing.  The wing is different in areas, but not substantially.  The only Hellcats pressed into use with the 20's was the -5N, and they were so sparingly available, it is almost not worth mentioning.  The erection and maintenance manuals for the -5 list the 20mm as an "also available," and spend little time on it.  Mathman is right, give up on the -5N, there is no need.

Not only was the Hispano installation limited to only a portion of the F6F-5N run, those arriving in the combat area had them promptly removed due not having flash hiders. That made the cannons less than useless for night combat. When flash hiders became available they were reinstalled.

My regards,

Widewing

[F4UDOA]

Well I certainly can't leave this one alone.

Here it is.

My top reasons why the F4U was a better fighter and bomber than the F6F.

1. "That old book" Rafe mentions is by Barret Tillman called "Corsair, The F4U in WW2 and Korea. The story goes on to say that Butch O'Hare was so impressed that he deployed a squadron of F6F's to Hawai and brought one F4U-1 with him as his personel airplane that nobody else could fly. Also the opposing F4U pilot was Joe Clifton of some fame himself.

2. From the same book in an interview with Rex Barber noted P-38 pilot from Yamamoto fame. In an interview with Rex he says "If the US could have only built one fighter Bomber during the war it should have been the F4U". Pretty high praise from an AAF pilot.

3. Also from Tillmans book. An evalution board from the Navy with three combat pilots including Commnader of the VF-11 LT Commander Gordon Cady, Commander of the VF-1 (Returned from Tarawa) LT Commander Bernard Strean and Lt Colonel John Smith CO of the VMF-223.

All test were done on a CVE becuase of it's small size. The evaluation lasted three weeks and the findings were.

A. The F6F-5 was more maneuverable than a F6F-3 but not as maneuverable as an F4U-1D.
B. The F4U was "No doubt faster than the F6F"
C. The F4U-1D had better Zoom climb.  
D. The F6F had a wider field of vision and was generally easier to land aboard a carrier.
E. The F4U-1D is a better gunnery platform.
. "We determined that F4U was equally as good a carrier plane if not better".

4. From Butch O'Hares memoirs "Fatefull Rendevous" he mentions that he and his squadron had a contest for money with an F4U-1 squad in a climb to 20,000FT. He mentions that it was "generally excepted that the F4U could outclimb the F6F by 700FPM". His squad lost the bet. It is generally excepted in AH that the F6F can outclimb the F4U. However in side by side test with the FW190 and A6M-5 the F4U outclimbed the F6F-3/5 by a fair margin.

5. In the 1944 Joint fighter Conferance the F4U-1D was selected as the best carrier plane in production over the F6F-5 by a wide margin of 61% to 31%. This was Marine, Navy, AAF, RAF, Royal Navy, NACA and contractor pilots.

6. In a modern test of the SETP or "Socioty of Experamental Test Pilots" in 1989 with a F6F-5, FG-1D (F4U-1D from Goodyear), P-51D and P-47D-40 performed extensive test on these birds and found the FG-1D to be the best in terms of ACM also finding the F4U stall to be gentle. They also found the F6F to have excessive rudder forces as well as a resistance to maneuevr at high power and low speed. Also the weight of the f4U for these test was 11,000LBS well within combat weight. The weight of the F6F was 10,700LBS. In reality the F6F was 300lbs heavier than the F4U not the other way around.

FYI the SEPT is a group of military test pilots and the group was founded by CORKEY MEYER!!

7. According to Vought the Cdo of the F4U-1 is .020 and Cdo of the F6F-5 is .023. The F4U has 20SQft less wing area and a smaller cowl opening. Both A/C have the same engine, HP and HP curves. How they could be the same speed at 20,000FT with two functioning aircraft would either be an engine malfunction or pilot error. Especially since the F4U was 20+knots faster at sea level accoring to Corkey Meyer.

Myth

Indeed the F6F had a large pitot tube error.

However

Speed.

A. The error was discover in mid 1944 and was largely non-existant in F6F-5 prodution.
B. The error on the early F6F pitot tube was "ADD11.5 knots" according to the F6F-3/5 handbook at 300MPH IAS. However on the F4U-1 the Pitot tube error at 300MPH was "ADD 8 Knots". So the CAS differance between the two A/C was a whopping 3.5 Knots!!

Stall

According to the POH the F4U-1 stall with full flaps is virtually the same speed as the F6F with full flap at the same weight.

Durability and Ensign eliminator.

In almost the same exact number of total sorties flown the F4U had signifcantly less total loss of A/C despite dropping almost 3 times as many tons of ordinance. Also the F4U suffered far fewer operational losses and losses to AAA during the war according to the official Navy records.

To some it up in every evaluation of the F4U and F6F side by side the F4U proven to be superior. Only in annecdote does the F6F grow in performance.

[MAC]

Thank you F4UDOA.

Thanks for presenting the facts, because FACTS speak for themselves.

[Widewing]

Originally posted by F4UDOA
5. In the 1944 Joint fighter Conferance the F4U-1D was selected as the best carrier plane in production over the F6F-5 by a wide margin of 61% to 31%. This was Marine, Navy, AAF, RAF, Royal Navy, NACA and contractor pilots.

In almost the same exact number of total sorties flown the F4U had signifcantly less total loss of A/C despite dropping almost 3 times as many tons of ordinance. Also the F4U suffered far fewer operational losses and losses to AAA during the war according to the official Navy records.

To some it up in every evaluation of the F4U and F6F side by side the F4U proven to be superior. Only in annecdote does the F6F grow in performance.

First, let's list ALL of the comparison tests at the JFC.

Best all around cockpit: F6F-5 wins, F4U-1D doesn't even make the list.

Worst cockpit: F4U-1D is up near the top.

Best engine controls: F6F-5 scores ahead of F4U-1D.

Best gear and flap controls: F6F-5 is #1, F4U-1D is 3rd behind P-51D.

Best cockpit canopy: F4U-1D is 3rd, F6F-5 is 4th.

Most comfortable cockpit: F6F-5 is 2nd, F4U-1D is 7th.

Best all around visibility: F6F-5 ranks ahead of Corsair.

Best armor: Corsair 2nd, F6F-5 3rd.

Best overload takeoff: F6F-5 is first.

Best ailerons at 350 mph: F4U is second to P-51D, F6F-5 ranks 4th.

Best ailerons at 100 mph: F6F-5 is 1st, F4U-1D is 2nd.

Best elevators: F4U-1D is first, F6F-6 is second.

Best rudder: F6F-5 is first...Refutes what the SoETPs stated.

Best all around stability: F6F-5 is first, Corsair second.

Best characteristics 5 mph above stall. F6F-5 is first, F4U-1D is dead last.

Best dive stability: F4U-1D is first, F6F-5 is 3rd behind P-47.

Best instrument and night flying qualities: F6F-5 is first, F4U-1D is 3rd.

Best fighter above 25,000 feet: F4U-1D is ranked 3rd, F6F-5 is ranked 4th, and get this, the F4U-4 is ranked 5th! Doesn't this sort of indicate that at least some of these guys couldn't buy a clue if their name was Bill Gates?

Now, a few facts about the JFC. It was dismissed by all three services as a boondoggle. Testing was utterly subjective, nothing was instrumented and most pilots had little or no experience in the majority of the aircraft flown. Corporate test pilots showed where their loyalties lived. Service rivalry was readily apparent. AAF pilots who never took off or landed on a carrier were making judgements about carrier suitability... In short, the JFC was about as useless an event as could be imagined... A waste of time and money. Not only that, less than half of the pilots completed the questionaires, so any concensus is limited to only a segment of the test population.

One participant called the meeting, "an opportunity to play with airplanes, talk airplanes, pat themselves on the back and then go get drunk."

Where did you get that "In almost the same exact number of total sorties flown" stuff?

Facts: F4Us flew 62,051 combat sorties, they shot down 2,140 Japanese and finished the war with an 11/1 kill to loss ratio.

F6Fs flew far more (just over 100,000 I believe) sorties and shot down 5,203 Japanese aircraft and finished the war with a 19/1 kill to loss ratio.

Don't misunderstand me, I have always been a big fan of the F4U. But, if I had to pick one as an "air superiority fighter", I'd take the Hellcat without second thoughts. Unless the F4U-4 is offered, in which case that would be my selection.  

My regards,

Widewing

[HoHun]

Hi Shuckins,

>Several months ago I participated in a post where the topic was the Hellcat's top speed.  There was considerable debate about whether or not it was correctly modeled in AH.  

OK, let's look at the numbers from the BuAer data sheets:

F4U-1D, R-2800-8W, MIL, 12175 lbs, 2930 fpm @ sea level, 396 mph @ 23900 ft
F6F-5, R-2800-10W, MIL, 12740 lbs, 2850 fpm @ sea level, 380 mph @ 23400 ft

So far, pretty evenly matched.

F4U-1D, R-2800-8W, Combat, 12175 lbs, 3370 fpm @ sea level, 409 mph @ 19900 ft
F6F-5, R-2800-10W, MIL power, 12740 lbs, 2980 fpm @ sea level, 380 mph @ 23400 ft

This is looking strange now.

First, the gain in sea level climb rate looks greatly inferior for the F6F. However, that can be explained: The F4U data sheet implies use of neutral supercharger gear, while the F6F data sheet doesn't. The F4U would climb at about 3080 fpm without that, which would be perfectly in line with the F6F data.

But what about the speed? The F6F gets no speed increase at all from combat power! Well, that's due to the absolute top speed being unaffected. The F6F does indeed get a power increase, but high gear full throttle height is just 18000 ft compared to the 19900 ft of the F4U. In MIL power, the F4U had a 500 ft higher full throttle height, so why is it 1900 ft now?

A similar effect can be seen in the climb graph now that we know what to look for: At climb speed, MIL power high gear full throttle height is about 21000 ft for the F4U and 20200 ft for the F6F. Combat power full throttle height is 17000 ft for the F4U, but only about 15200 ft for the F6f. The F6F loses about 1000 ft here.

A third, more subtle effect is that the F4U seems to gain some performance even above full throttle height with the combat power setting, while the F6F, if the speed and climb graphs were extrapolated, would actually lose some!

What's wrong with the F6F-5? It does't seem able to exploit the full power from the water injection. The reduced full throttle heights make me wonder if the F6F-5 can't employ ram effect for some reason when at combat power. In some aircraft (like the P-51), it's possible to draw in unrammed air (through a filter) if desired, this might be what we're observing with the F6F-5.

The other question is whether the F4U actually increases rpm when going to combat power as suggested by the graphs, while the F6F-5 doesn't. (The performance increase might also be due to the charge-cooling effect of the water injection, or due to artistic liberty of the guy drawing the chart ;-)

In any case, there's something strange about F6F-5 performance.

Regards,

Henning (HoHun)

[joeblogs]

I'll push back on one point only. If you read Lundtrsom's "First Team" you'll find a very high proportion of all F4f losses were due to accidents on take-off or landing. Many squadrons had just transitioned to the f4f and after Midway, many squadrons were simply green.

After that experience, it is only natural for the Navy to be conservative about landing characteristics in 1942. The fact that the oleo problem was fixed by 1944 and US fighter crews had more time to train in their mounts suggests that 1942-43 and 1944-45 were not comparable.

-blogs

Originally posted by F4UDOA
Well I certainly can't leave this one alone.

Here it is.

My top reasons why the F4U was a better fighter and bomber than the F6F.

1. "That old book" Rafe mentions is by Barret Tillman called "Corsair, The F4U in WW2 and Korea. The story goes on to say that Butch O'Hare was so impressed that he deployed a squadron of F6F's to Hawai and brought one F4U-1 with him as his personel airplane that nobody else could fly. Also the opposing F4U pilot was Joe Clifton of some fame himself.

2. From the same book in an interview with Rex Barber noted P-38 pilot from Yamamoto fame. In an interview with Rex he says "If the US could have only built one fighter Bomber during the war it should have been the F4U". Pretty high praise from an AAF pilot.

3. Also from Tillmans book. An evalution board from the Navy with three combat pilots including Commnader of the VF-11 LT Commander Gordon Cady, Commander of the VF-1 (Returned from Tarawa) LT Commander Bernard Strean and Lt Colonel John Smith CO of the VMF-223.

All test were done on a CVE becuase of it's small size. The evaluation lasted three weeks and the findings were.

A. The F6F-5 was more maneuverable than a F6F-3 but not as maneuverable as an F4U-1D.
B. The F4U was "No doubt faster than the F6F"
C. The F4U-1D had better Zoom climb.  
D. The F6F had a wider field of vision and was generally easier to land aboard a carrier.
E. The F4U-1D is a better gunnery platform.
. "We determined that F4U was equally as good a carrier plane if not better".

4. From Butch O'Hares memoirs "Fatefull Rendevous" he mentions that he and his squadron had a contest for money with an F4U-1 squad in a climb to 20,000FT. He mentions that it was "generally excepted that the F4U could outclimb the F6F by 700FPM". His squad lost the bet. It is generally excepted in AH that the F6F can outclimb the F4U. However in side by side test with the FW190 and A6M-5 the F4U outclimbed the F6F-3/5 by a fair margin.

5. In the 1944 Joint fighter Conferance the F4U-1D was selected as the best carrier plane in production over the F6F-5 by a wide margin of 61% to 31%. This was Marine, Navy, AAF, RAF, Royal Navy, NACA and contractor pilots.

6. In a modern test of the SETP or "Socioty of Experamental Test Pilots" in 1989 with a F6F-5, FG-1D (F4U-1D from Goodyear), P-51D and P-47D-40 performed extensive test on these birds and found the FG-1D to be the best in terms of ACM also finding the F4U stall to be gentle. They also found the F6F to have excessive rudder forces as well as a resistance to maneuevr at high power and low speed. Also the weight of the f4U for these test was 11,000LBS well within combat weight. The weight of the F6F was 10,700LBS. In reality the F6F was 300lbs heavier than the F4U not the other way around.

FYI the SEPT is a group of military test pilots and the group was founded by CORKEY MEYER!!

7. According to Vought the Cdo of the F4U-1 is .020 and Cdo of the F6F-5 is .023. The F4U has 20SQft less wing area and a smaller cowl opening. Both A/C have the same engine, HP and HP curves. How they could be the same speed at 20,000FT with two functioning aircraft would either be an engine malfunction or pilot error. Especially since the F4U was 20+knots faster at sea level accoring to Corkey Meyer.

Myth

Indeed the F6F had a large pitot tube error.

However

Speed.

A. The error was discover in mid 1944 and was largely non-existant in F6F-5 prodution.
B. The error on the early F6F pitot tube was "ADD11.5 knots" according to the F6F-3/5 handbook at 300MPH IAS. However on the F4U-1 the Pitot tube error at 300MPH was "ADD 8 Knots". So the CAS differance between the two A/C was a whopping 3.5 Knots!!

Stall

According to the POH the F4U-1 stall with full flaps is virtually the same speed as the F6F with full flap at the same weight.

Durability and Ensign eliminator.

In almost the same exact number of total sorties flown the F4U had signifcantly less total loss of A/C despite dropping almost 3 times as many tons of ordinance. Also the F4U suffered far fewer operational losses and losses to AAA during the war according to the official Navy records.

To some it up in every evaluation of the F4U and F6F side by side the F4U proven to be superior. Only in annecdote does the F6F grow in performance.

[Shuckins]

HoHun,

If you look more closely at the data from the BuAer you'll notice that the F6F-5 was listed as being 600 pounds heavier than the Corsair.  That indicates that, for some reason, the Hellcat had been loaded to a greater takeoff weight than the Corsair.  Empty weights of the two aircraft are virtually identical, with the Corsair being less than 100 pounds lighter than the Hellcat (This is comparing a late model F4U-1 against the F6F-5;  I have no data for the -1D Corsair, which is supposed to be heavier than the earlier models.)  

Fighter overload weights for the two aircraft are 11,693 lbs for the -5 Hellcat and 11,962 pounds for the late model F4U-1 with water injection.  These loads were with full internal fuel and sans drop tanks and ordnance.

As to low-speed handling qualities I refer you to an article by Corky Meyer in a recent edition of Flight Journal magazine.  This was a special edition about the Corsair.  Much has been made by some fighter enthusiasts about the fact that the RNAF carrier qualified the Corsair a full year before the U.S. Navy did.  Corky asked Captain Eric Brown point blank about this, hoping that he could shed some light on the matter.  Brown stated that the RNAF's test pilots quickly found out why the U.S. navy pilots were suffering such high accident rates with the Corsair.  He was quite blunt about the F4U's dangerous low-speed handling and torque stall characteristics during waveoff conditions.   Captain Brown said that, in essence, the RNAF cleared the Corsair for carrier operations because it had no British aircraft designed from the ground up to withstand the rough-and-tumble conditions of carrier warfare.  Therefore, they just accepted the higher accident and casualty rates.

How typically British..."Carry on old chaps!  Stiff upper lip!"

[HoHun]

Hi Shuckins,

>That indicates that, for some reason, the Hellcat had been loaded to a greater takeoff weight than the Corsair.  

Well, the BuAer load-out of both aircraft comprises of:

F6F-5: 1500 lbs fuel, 135 lbs oil, 287 lbs ammuntion (20 mm + 12.7 mm) = 1922 lbs

F4U-1D: 1422 lbs fuel, 92 lbs oil, 264 lbs ammunition (12.7 mm, my calculation) = 1778 lbs

(Oil and ammunition weights calculated by me, oil for the F4U-1D load condition is explicitely given and apparently not topped up, while the F6F-5 sheet only gives total oil capacity. There's also 16 gals of water in the F6F-5, sufficient for at least 10 min, while the F4U-1D has enough for 8.5 min, but no capacity given so I neglected water in my calculation.)

Working backwards from the gross weight for each condition, we get the following empty equipped weights:

F6F-5: 10818 lbs (BuAer Design 11000 lbs, Basic 10035 lbs, Empty 9238 lbs)
F4U-1D: 10397 lbs (Empty Actual 9014 lbs)

No idea what's going on there!

>Captain Brown said that, in essence, the RNAF cleared the Corsair for carrier operations because it had no British aircraft designed from the ground up to withstand the rough-and-tumble conditions of carrier warfare.  Therefore, they just accepted the higher accident and casualty rates.

Roger that! The Seafire must have been much worse than the Corsair - Seafire/Sea Fury pilot Mike Crosley in "Up in Harm's Way" mentions that the Sea Fury accident rate in the Korean War much much smaller than those they had had with the Seafire in WW2. And they operated the Sea Fury under very difficult conditions, while they had flown the Seafire in the calm mediterranean!

Regards,

Henning (HoHun)

[Rafe35]

For the Corsair in many respect was the greatest fighter produced in World War II by any nation.  Quickly it proved superior to the famous Hellcat in many ways and appeared increasingly on carriers.  Because the Corsair proved capable of handling a stream of design modifications, it stayed in production for years, and hundreds of USN and Marine pilots flew it during the Korean War.  The Corsair remained in reserve serivce through the early 1960s.

[TequilaChaser]

If the F4U-1 , C model or D model, was so much better than the F6F why did the blue angels fly  the F6f instead of the F4U?

I mean they (the blue Angels) were formed right after the end of WW2, one would think the Navy would use its best performing Fighter Plane, right?

[Rafe35]

Originally posted by TequilaChaser
If the F4U-1 , C model or D model, was so much better than the F6F why did the blue angels fly  the F6f instead of the F4U?

I mean they (the blue Angels) were formed right after the end of WW2, one would think the Navy would use its best performing Fighter Plane, right?

I like F6F turn into Blue Angels while they are no longer as a fighter role in probably 1947 or later and F4U was still as a fighter role til the Korean War.

[TequilaChaser]

Originally posted by Rafe35
I like F6F turn into Blue Angels while they are no longer as a fighter role in probably 1947 or later and F4U was still as a fighter role til the Korean War.

I like the F6F too....

check this link: History Of The Blue Angels

They went from the F6F Hellcat(prop) to the F8F Bearcat(prop)  to the F9F-2(jet)

guess the F8F was better than the F4U also

A cherished memory of mine: -->
I got to do corrosion control and help paint one of the first 3 of these  F18's at NAS Cecilfield when I was  stationed there.
 "On November 8, 1986, the Blue Angels celebrated their 40th anniversary by unveiling its present aircraft, the sleek McDonnell Douglas (now Boeing) F/A-18 Hornet. The Hornet is the first dual-role fighter/attack aircraft serving on the nation's front lines of defense."

[F4UDOA]

WW,

In answer to your question about my source.

Where did you get that "In almost the same exact number of total sorties flown" stuff?

Facts: F4Us flew 62,051 combat sorties, they shot down 2,140 Japanese and finished the war with an 11/1 kill to loss ratio.

F6Fs flew far more (just over 100,000 I believe) sorties and shot down 5,203 Japanese aircraft and finished the war with a 19/1 kill to loss ratio.

My source is the Naval Historic branch. They have a large document on there website detailing sorties kills etc.

I was writing from memory but I was very close to the real numbers. I posted the page on my site so you can download it in PDF.

A few things.

1. Actual number of combat sorties.

F6F- 66,350.
F4U- 64,051 That's pretty close.

2. Total losses for both are

F6F - 2,461 to all causes.
F4U - 1,624 to all causes

3. Loss to enemy AAA

F6F - 553
F4U - 349

4. Tons of ordinance dropped

F6F - 6,503
F4U - 15,621 That is a huge margin

5. The FM-2 had a higher K/D than the F6F by a wide margin with a claim of 32 to 1 K/D.  

Also from the same statistical data although not the page I posted the F6F and F4U kills by year.

1943 total kills

F6F - 322
F4U- 636

1944 total kills
F6F- 3,051
F4U-492

During the month of June the F6F had 736 kills claimed and the F4U had 2 kills claimed. During the month of Oct the F6F claimed 1,016 NME and the F4U claimed 1!!

In fact from April 1944 through November 1944 the F4U total kills claimed was 5!! While the F6F claimed 2,669!! Can you say The Great Marianas Turkey Shoot!

It was not until May 1945 when parity in numbers was reached that the F4U claimed higher kills than the F6F with 251 to 234. The F4U remained tops through the war in total kills beyond that point.

As to the JFC.

1. The F4U-4 was only flow by 3 pilots. Acounting for it low result in votes tallied. The F2G was there as well and was not flown by any attendies also rsulting in almost no votes.

2. In votes for best fighter under 25,000FT

F8F - 30%
P-51D - 29%
F4U-1C/D - 27%
F7F - 6%
F6F - 2%
Mosquito - 2%
F4U-4 - 2%
F2G - 2%

If you go by your assertion that patronage was responsable for the result then lets assume that the Vought and Goodyear pilots that voted for the F4U-4 and F2G would have voted for the F4U-1 that makes it number 1 right??

In anycase it is apparent what the top fighter aircraft of the day were according to the school of thought at the time.

You may discount results of the meeting but the fact remains that a Naval revue board decided the same. As well as the SEPT and evaluations of the F6F and F4U against similar foes.

Here is the Naval historic Branch record of things.



http://home.comcast.net/~markw4/nasc1.pdf