F4U-4 Start of Production

[Dana Bell]

IN early 1944 the BuAer plans had Vought converting completely to F4U-4 production by year's end, Brewster converting to F3A-1D production during the summer, and Goodyear converting to F2G production in late-44/early-45. The death of Brewster put an end to that - there was no way the Navy could reduce total Corsair production while converting to newer variants. Fired in June 1944, Brewster never built a single F3A-1D; Goodyear picked up the FG-1A and FG-1D slack (including new orders for the Fleet Air Arm and New Zealand), but couldn't begin F2G production until the war was nearly over. Vought had ended production of all F4U-1 versions, switching over to F4U-4s by December.

Cheers,


Dana

 

[Vincenzo]

Sorry Dana but this is not possible, the Vought built more -1 of their production to '44

Edit: i've a note, w/o reference, that last -1 was delivered the 2nd February '45 3rd edit i found the reference is from americancombatplanes.com
2nd Edit in "Vought F4 Corsair: Carrier and Land-Based Fighter" is reported a production to February '45 of 4,996, so to February '45were built 297 -4,

 

[Dana Bell]

Hi Vincenzo,

My notes are from the BuAer's contract files. A December 1944 memo pointed out that F4U-1D production had already been completed; the lines had completely switched to F4U-4s. Delivery is another matter; at several times hundreds of Corsairs were stranded at plants due to heavy snow falls and a lack of ferry pilots -- perhaps the winter of 1944/45 repeated this.

I can't explain where other authors get their data -- I'm just sharing what the official records at the National Archives say.

Cheers,



Dana

 

[Dawncaster]

Some 10 mph faster than 1944 P-47Ds, and some 15 mph slower than P-47M/N. The M and N will be notably faster at 30 kft and above, maybe 50 mph plus. At SL the Corsair is some 10 mph faster than M/N, and some 40 mph than late P-47Ds.
The P-47M should climb a tad faster, the D and N slower than F4U-4.

Maybe it's time to update the old graph. added wartime vought's curve.

One thing to note is that the known performance of the P-47M/N, such as the 473 mph Vmax, was achieved at normal or combat load condition(less fuel).

The P-47M/N outclimb the F4U-4 even at low altitude, but with less(and better) fuel.

Climb to 10k

F4U-4 12,435 lbs 234 gal full internal fuel 60"hg (Vought) : 2.5 min
F4U-4 12,420 lbs 234 gal full internal fuel 60"hg (USN) : 2.9 min
F4U-4 12,450 lbs 234 gal full internal fuel 70"hg (Vought) : 2.3 min
P-47M 13,262 lbs 205 gal normal load fuel 72"hg : 2.6 min
P-47N 13,962 lbs 205 gal normal load fuel 72"hg : 2.8 min
P-47N 17,867 lbs 557 gal full internal fuel 72"hg : 3.7 min

Climb to 20k

F4U-4 12,435 lbs 234 gal full internal fuel 60"hg (Vought) : 5.5 min
F4U-4 12,420 lbs 234 gal full internal fuel 60"hg (USN) : 5.9 min
F4U-4 12,450 lbs 234 gal full internal fuel 70"hg (Vought) : 5.0 min
F4U-4 12,480 lbs 234 gal full internal fuel 70"hg (USN) : 4.9 min
P-47M 13,262 lbs 205 gal normal load fuel 72"hg : 5.4 min
P-47N 13,962 lbs 205 gal normal load fuel 72"hg : 5.9 min

References :
1. Comparison of P-47D, P-47M and P-47N Performance by ARMY AIR FORCES MATERIEL CENTER
2. Model Specification for Republic Model – AP-16a; Fighter Offensive; Air Corps Type Designation P-47M by REPUBLIC AVIATION Corporation
3. Model Specification for Republic Model – AP-16b; Fighter Offensive; Fighter Bomber; VLR Escort Fighter; Air Corps Type Designation P-47N-5-RE by REPUBLIC AVIATION Corporation
4. F-47N STANDARD AIRCRAFT CHARACTERISTICS by AIR MATERIEL COMMAND U.S. AIR FORCE
4. General Performance Data by VOUGHT
5. F4U-4 STANDARD AIRCRAFT CHARACTERISTICS by BUREAU OF AERONAUTICS, NAVY DEPT
6. F4U-4 AIRPLANE CHARACTERISTICS & PERFORMANCE by BUREAU OF AERONAUTICS, NAVY DEPT

 

[GregP]

I have service introduction in Oct 44 for the F4U-4. I do not have the date when some specific number of them were operating, but there are many statements that adoption was "rapid." What that means exactly is not quite clear to me.

 

[Vincenzo]

I have service introduction in Oct 44 for the F4U-4. I do not have the date when some specific number of them were operating, but there are many statements that adoption was "rapid." What that means exactly is not quite clear to me.

this is propaganda of -4 fans, i've checked the "Location of US Naval Aircraft" the first time they show in it is the 24th February '45 with CASU 21 at Norfolk,

 

[Dana Bell]

I'm sorry, Vincenzo,

Propaganda? At some point you have to decide if you're asking a question or if you're challenging us to prove something to you. Tell us what you're trying to prove so we can all agree with you...

This autumn I plan to resume work on my F4U-4 book - I should have access to the production lists, if the Archives will only reopen. Perhaps then we can come up with actual numbers for you.

Cheers,



Dana

 

[Vincenzo]

I'm sorry, Vincenzo,

Propaganda? At some point you have to decide if you're asking a question or if you're challenging us to prove something to you. Tell us what you're trying to prove so we can all agree with you...

This autumn I plan to resume work on my F4U-4 book - I should have access to the production lists, if the Archives will only reopen. Perhaps then we can come up with actual numbers for you.

Cheers,



Dana

Dana i'm sorry but also your data give a clear that is not possible that -4 was in service introduction in October '44, your data tell us that sometimes in December '44 the production line was switched to -4

edit and i've posted already twice that before of 24th February '45 there is not -4 on "Location of US Naval Aircraft" and also in the 24th February they are not in operational unit but in a CASU

 

[Dana Bell]

Hi again, Vincenzo,

What I wrote was "...switching over to F4U-4s by December" which simply means that there was no doubt that production had begun before that time, and that -1 production had ended. Production lists (which I still don't have) will give us a much more detail, but I have a series of Vought walkaround photos dated 11 October 1944 showing one of the first production F4U-4s.

I can't say where the earliest -4s were sent - I just don't know. The Archives files will include delivery destinations for every aircraft - some probably went to pools, others to transitional training units that would not always be listed in the Locations of Naval Aircraft.

Cheers,



Dana

 

[Vincenzo]

From memory there were 4 or 5 -4 prototypes take from -1 production line, now i've not time but is possible found the buaer number for this prototypes

Edit: the Buaer numbers for the -4 prototypes were: 49763, 50301, 80759-63, from "Vought F4U Corsair" WarbirdTech 4

 

[Dawncaster]

The -4 had a 13.5 gallon water tank versus 10 gallons on the -1 (with WI). Max time was about 5mins before water exhaustion.

Where did you get this from?

In order to GET a WER rating a test engine had to survive 7 1/2 hours at the WER rating. Granted it is 5 minutes at a time. Run 5 min at WER and then a 5 or more minutes at cruise or idle to lower temperature and then back to the WER setting.

The ADI was NOT a one shot deal. The F4U-1 carried just over 10 gals of ADI at roughly 7.5lb per gallon that is over 75lbs.
Flow rate for 2400hp was 9.2lbs per minute, or a bit over 8 minutes worth.
Flow rate for 1900hp in higher blower was 7.2lbs per minute. WER rating for the R-2800-8 was 1975hp at 20,000ft ( with RAM) or about 10 minutes worth. Granted it should be used 5 minutes at a time.

WER was for use in COMBAT only. Climbing to operational height should not use WER ( it shouldn't even use Military Power most of the time). Military power was not even allowed to be used for more than 5 minutes in the climb on the early planes.

The P-47 speeds are also using WER and ADI. The P-47 carried more ADI but would be subject to the same limitations.

ADI flow for 2500hp was supposed to be 11.5 lbs per minute. or 8.8 minutes at 2500hp for the F4U-4?

Of course that is only for the engine running in Neutral.

Another source gives a test result in flight tests of 625lbs per hour at WER at over 20000ft or just over 10lbs per hour or about 7.5 minutes for a F4U-1.

Pilots may have run Merlins at WER settings for well over 5 minutes and gotten away with it ( we don't hear much from the ones who didn't get away with it) but it was not approved practice ( written in manuals)

The F4U-1 had a water supply of about about 8.5 minutes of WEP.

And the USN considered the F4U-1's 20 minute combat to use 8.5 minutes WEP and 11.5 minutes Military power for standard mission profile.

The F4U-4 had a water supply of about 12 minutes of WEP.

And the USN considered the F4U-4's 20 minute combat to use 10 minutes WEP and 10 minutes Military power for standard mission profile.

In this case, not all 12 minutes of WEP were used, which seems to assume that WEP and MIL are alternately used every 5 minutes due to a 5 minute time limit for each power ratings.

My point was that when the water is gone (~8mins - thanks) then so is WER. On a Merlin WER had no fixed time limit. Pilots were advised not to use it for more than 5mins at a time, but there was no clockwork mechanism that would return throttle to a lower setting. With ADI when the water is gone, the engine will go with it unless the pilot throttles back (apparently automated - thanks).

BTW, there are speed and climb rate figures for the -4 using WER all the way to 41000ft, but I think these must have been obtained with aircraft having an increased supply of water.

It applies not only to the F4U-4, but also to all aircraft with a 5 minute limit for WEP, because a cooldown was required after using 5 minutes of WEP.

And even assuming that the F4U-4 climb to about 40,000 feet using WEP, It is not necessary for all of the water to be used. In other words - 13.5 gallons with 12 minutes WEP was enough.

The F4U-4 can climb to 40,000 feet in about 22 minutes without using any water. If WEP is used in this situation, It will be a time similar to the 20-minute combat of the standard mission profile described above, so the F4U-4 will not run out of water. in addition, due to the supercharger's critical altitude, the benefits of WEP will be lost at high altitude, so there is NO water consumption at above critical altitude. and It is reasonable to assume that the curves considered to have always used WEP have been obtained with more test flights rather than special aircraft modifications for extra water supply.

Lastly, as can see from the above standard mission profile, air combat was not an endless fighting arena like Valhalla, so it's unpractical to assume too much WEP time. USAAF and USN assumed 5-10 minutes WEP for 20 minutes of combat time and I also think it's reasonable.