F4U-4 Start of Production

[Conslaw]

It was my understanding that Vought shifted production from the F4U-1D to the F4U-4 in late 1944. I just saw a site which says that a Goodyear produced FG1D was produced in April 1945. (Goodyear FG-1D Corsair - Manufacturer was Goodyear Aircraft Corp. from a design by Chance Vought) Did Goodyear ever shift to the dash-4? It seems like the dash-4 was very slow in being delivered to combat units, with many units still not equipped with dash-4 by August 1945. What accounts for the delay? Was there a first-in-first-out policy for aircraft inventory?

 

[GregP]

Goodyear made the FG-1 in the D, E (radar) and K (drone) models. They also made an FG-3 whch had a turbosupercharger, They had an FG-4 on paper but never delivered it. The Marine ground attack variant was the AU-1, redesignated from the F4U-6. (the F4U-7 was an AU-1 developed for the French Navy)

They also delivered the F2G-1 and F2G-2. The difference between the two was the F2G-1 had a manual wing fold with a 14 foot propeller and the F2G-2 had hydraulic folding wings, a 13 foot propeller and an arrester hook for carrier operations. But, with only 10 built, they were never a factor except in post-war races.

According to Wiki (not the most reliable) the F4U-4 fully reequipped US Naval squadrons from about 4 months before the end of the war, which would seem to indicate about May 1945 onwards. According to Vought aircraft, the first flight of a production F4U-4 was in September 1944 and it arrived on the battlefront in June 1945. Still other references say "last 4 months of the war" and, by that time, the Japanese resistance was not overwhelming, probably relegating the F4U-4 to less than stellar perfromance against the enemy due primarily to lack of targets and decent pilot opposition. Classic Fighters of America says it arrived in combat in "early 1945," which can be interpreted in many ways. They say it was in Pacific combat for about 6 months.

So, the real story is probably anywhere from 3 - 6 moths before the end of the war. Either way, the Japanese resistance was winding down, pilot quality-wise, and the F4U-4 never got chance (a good thing?) at the Japanese in their prime. It has a pretty good claim to "best fighter" in it's own right, but the war was winding down before it got it's chance.

 

[Conslaw]

If you look at this disposition report of navy marine aircraft as of July 21, 1945, http://www.history.navy.mil/a-record/ww-ii/loc-ac/1945/jul1945/21-7-45.pdf it appears that there are at least as many -1 Corsairs as -4s deployed to forward units. It seems likely to me that there was either a formal or informal first-in first-out policy regarding aircraft supply lines.

 

[GregP]

Makes sense that the entire population of F4U-1's would not have been replaced yet since the first F4U-4's were getting there only within a few months of war's end.

 

[Conslaw]

If I were the Navy, though, and I had this world-beating fighter sitting on the shelf (the F4U-4), it seems like I would have moved heaven and earth to get it into action. I guess in the real world, you had ships full of F4U-1 spare parts slowly making their way across the wide Pacific. There was really no NEED for a hotter fighter than the F4U1D/FG1D.

 

[RCAFson]

I looked into the F4U-4 sometime ago, and IIRC, the hottest variant, but whose performance is often quoted was introduced post-war.

The wartime F4U-4 used the R2800-18w engine, but post war variants were fitted with the more powerful R2800-42w.

 

[tomo pauk]

The F4U-4 with -18W engine was managing some 445 mph at 25000 ft - that would be hot airplane in anyone's book?

 

[gjs238]

The F4U-4 with -18W engine was managing some 445 mph at 25000 ft - that would be hot airplane in anyone's book?

How does that compare to the P-47?

 

[tomo pauk]

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.

 

[RCAFson]

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.

However, these F4U-4 speeds were obtained using combat power with water injection - which was limited to about 5 mins total, and after that the engine would self destruct (literally) if not throttled back. The use of water injection is quite deceiving since, for example, if it is used to boost climb rates to 20,000ft it is gone, and is not available for subsequent combat.

 

[tomo pauk]

However, these F4U-4 speeds were obtained using combat power with water injection - which was limited to about 5 mins total, and after that the engine would self destruct (literally) if not throttled back.

Not sure what you're aiming at - no US engine in ww2 was allowed for more than 5 minutes at WER, be it with or without ADI. The often quoted ~440 mph figures for the Merlin Mustang were also obtained with engine running at WER, ie. 5 min rating.

The use of water injection is quite deceiving since, for example, if it is used to boost climb rates to 20,000ft it is gone, and is not available for subsequent combat.

Do we know how many minutes the ADI liquid lasted in US fighters, once engaged? How many fighters were climbing from SL to 20000 ft while using WER?
There is nothing deceiving in ADI system, extra power was always useful for pilots. The Spitfire V with ADI would not have any problems to beat the Fw-190 under 20000 ft.

 

[RCAFson]

Not sure what you're aiming at - no US engine in ww2 was allowed for more than 5 minutes at WER, be it with or without ADI. The often quoted ~440 mph figures for the Merlin Mustang were also obtained with engine running at WER, ie. 5 min rating.

The use of WEP on a Merlin had no absolute time limit and the engine could be run continuously at the WEP rating until fuel exhaustion or the engine eventually fails, but on engines like the 2800-18W, which used water injection during combat (WEP) power, there was an absolute limit determined by the water capacity of the aircraft. If the engine was run at the WEP rating for even a few seconds after the water supply was exhausted the engine would self destruct and probably destroy the aircraft as well (see Guyton for details).

Do we know how many minutes the ADI liquid lasted in US fighters, once engaged? How many fighters were climbing from SL to 20000 ft while using WER?
There is nothing deceiving in ADI system, extra power was always useful for pilots. The Spitfire V with ADI would not have any problems to beat the Fw-190 under 20000 ft.

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.

 

[tomo pauk]

The use of WEP on a Merlin had no absolute time limit and the engine could be run continuously at the WEP rating until fuel exhaustion or the engine eventually fails, but on engines like the 2800-18W, which used water injection during combat (WEP) power, there was an absolute limit determined by the water capacity of the aircraft. If the engine was run at the WEP rating for even a few seconds after the water supply was exhausted the engine would self destruct and probably destroy the aircraft as well (see Guyton for details).

The 67 in boost was WER in USAF parlance*, and we can see here its limited for 5 minutes. The 61 in boost being military rating*.

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.

Thanks.
I've checked the figures myself, the P-47 was carrying 30 USG, the P-63 (when fitted with ADI) 25 USG. That would be 15 minutes?

*all in this case

 

[Shortround6]

However, these F4U-4 speeds were obtained using combat power with water injection - which was limited to about 5 mins total, and after that the engine would self destruct (literally) if not throttled back. The use of water injection is quite deceiving since, for example, if it is used to boost climb rates to 20,000ft it is gone, and is not available for subsequent combat.

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.

 

[Shortround6]

The use of WEP on a Merlin had no absolute time limit and the engine could be run continuously at the WEP rating until fuel exhaustion or the engine eventually fails, but on engines like the 2800-18W, which used water injection during combat (WEP) power, there was an absolute limit determined by the water capacity of the aircraft. If the engine was run at the WEP rating for even a few seconds after the water supply was exhausted the engine would self destruct and probably destroy the aircraft as well (see Guyton for details).

That rather contradicts the pilots manual. In either low or high blower the supercharger pressure regulator automatically kicks in and lowers the manifold pressure for the pilot when the ADI runs out. In Neutral (low altitude) it does NOT and the pilot has to throttle back. There was a de-enrichment setting on the carburetor which dropped the fuel consumption from about 280 gallons and hour down to 245 gallons and hour when the ADI was operating. The extra fuel acting something like ADI.

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.

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)

 

[RCAFson]

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.

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.

 

[Shortround6]

Tests were often done by getting the plane to altitude using either max continuous power or Military power and THEN kicking in the WER, a few test planes were fitted with larger than normal ADI tanks for tests. Corsairs seem to have trouble keeping the engines cool using ADI, at least the F4U-1.

The only "clock work" mechanism on the Merlin was keeping the engine within normal operating temperature ( a limit on all engines for both WER or Military power) and fuel consumption.

A Mustang using WER is doing over 400mph and 15 minutes of that would cover over 100 miles. The actual NEED to use WER for that distance is mighty slim. A 1954 F-51D manual gives a 5 minute limit for "combat/WER" (67") power and 15min for Military power (61"). Fuel consumption is about 210 gallons an hour for "combat" or about 52 gallons in 15 minutes. Fuel consumption for Military is 180 gallons an hour. Fuel consumption (clean/wing racks) at 25,000ft doing a true air speed of 413mph using 2700rpm and 46" MAP is 98 gallons an hour.

As can be seen, unless running from an Me 262, the need to use WER for 15 mins is likely only on the rarest of occasions and is thrashing the engine to no good purpose. If running from an Bf 109 the 109 has either run out out of fuel or headed back to base long before the 15 min are up.

What anybody's fighters could do for WER settings on a cold winter day at altitude is a far cry from what they could do near sea level in the tropics. Both engine cooling and temperature at the intake to the carburetor being seriously affected.

 

[tomo pauk]

The Bf-109 that might be chasing an Allied plane has it's own time limit for maximum power (Notleistung mostly) of 5 minutes. Same for Fw-190, or wasn't it 3 min for it's BMW-801?

The operation outside the book was one of things that got P-38 out as a contender for the 8th AF long range escort for the 1944.

 

[Shortround6]

Even if you throw out the time limit the German fighters didn't carry enough fuel to chase (or run from) a Mustang for 15 minutes without being in a serious fuel crisis.


A damaged plane ( shot up with flaps of metal sticking out) might use high power settings for an extended period of time to get out of danger but again we don't hear much about the pilots who tried that and blew the engine up.

 

[Vincenzo]

I know this is a bit old thread but start an other with same title imho is not good
So when start the production of F4U-4? and the deliveries?
I've read that the first flight in in September '44 and the first delivery the 31st October '44
but looking to the Location of US Naval Aircraft they show the first time the -4 the 24th February '45 with 39 copies in the CASU 21 at Norflok
the Vought built 4,632 fighters to '1944 (from Army Air Force Statistical Digest) and ever the Vought built 4,699 -1 (many online references)
I've the idea that that September or October copies are just the variant prototypes and the delivery started not before of January '45 if not later, like sometime within the 20th and the 24th February, Norfolk is near to the Vought factory
Someones can help?