(X)F4U for service ASAP?

[tomo pauk]

The F4U received plenty of changes in order to became a major ww2 aircraft. The changes, while gave increased combat capability, also cost time. Wonder whether it would be any advantage for the Allied was effort to start production of the as good as un-changed XF4U in order to have a good performer as early as start of 1942?
Of course, the defects of the XF4U that affected security need to be addressed, like aileron modifications.

 

[tomo pauk]

Wow, quite a feedback

Some data about the XF4U-1:

http://www.alternatewars.com/SAC/XF4U-1_Airplane_1443_Performance_(Tommy).pdf

 

[Shortround6]

Thank you for the data but looking at it and you can see a few reasons why they didn't put the plane into production.

TWO .50 cal guns with 200rpg????
Granted the cowl guns were not present but that is light armament indeed.
The test engine was about 200hp down on power at altitude compared to the service engine uses later.

Test aircraft may not have had armor or self sealing tanks.

Performance charts are with 175 gallons of fuel and less armament than a F4F-3. Speed is good but climb is lousy.

 

[tomo pauk]

It is 300 rpg for the .50s, as maximum. I'd get rid of the .30s and AA bombs, while using that space weight allowance to install another pair of .50s in the wings.
I'd agree with you that XF4U-1 probably did not carried any worthwhile protection. The R-2800-8 should be available in Feb 1942, in case airframe is as less modified as possible, the 1st production F4U might be accepted in March 1942?

edit: seems like 6 two-stage R-2800 B series were manufactured in 1941 (July-November). Not enough for service use in anything, but will enable tests and carrier certifications of F4U to be conducted before Perl Harbor attack, with B series engine?

 

[Shortround6]

The problems are that the performance figures are for a plane 325lbs lighter than than the plane carrying the bombs. (column #6)
There are only 208lbs of bombs. A pair of .50 cal guns are going to go about 132lbs and another 400 rounds of .50 cal ammo (200rpg) adds another 120lbs. Upping the ammo to 300rpg for all four guns adds another 120lbs or 160lbs more than the bombs weighed.

The F4U-1 was supposed to weigh 11,142lbs with 178 gallons of fuel, six .50cal guns and 1200 rounds of .50 cal (200 per gun) or 1443lbs more (about 15%) than the XF4U-1 carrying the bombs and the same amount of fuel. Something besides just armament and fuel tank/s changed.

 

[tomo pauk]

The F4U-1 carried 177 lbs worth of fuel tanks and their protection. The deflection plate was at 25 lbs, 53 lbs was pilots back armor. The bullet proof glass was also there. None of these were aboar of XF4U-1? The 'armament provision' (cradles, heaters, etc) was at 365 lbs, at what we add 1000 lbs worth of guns and ammo (6 x 400 rds). The XF4U-1 is at maybe 120 + 300 lbs for that, wing guns only?

The LMGs and their ammo were worth 125 lbs, per pdf posted above. Along with deletion of wing bombs, we save there 330 lbs total - enough for additional pair of .50s. The B series engine should give enough of extra oomph, to cater for extra protection, but as always, Corsair's pilots are best advised not to play the lightweight fighters game.

edit: the term 'armament provision' might also include armor installed??

 

[Shortround6]

The F4U-1 carried 177 lbs worth of fuel tanks and their protection. The deflection plate was at 25 lbs, 53 lbs was pilots back armor. The bullet proof glass was also there. None of these were aboar of XF4U-1? The 'armament provision' (cradles, heaters, etc) was at 365 lbs, at what we add 1000 lbs worth of guns and ammo (6 x 400 rds). The XF4U-1 is at maybe 120 + 300 lbs for that, wing guns only?

The LMGs and their ammo were worth 125 lbs, per pdf posted above. Along with deletion of wing bombs, we save there 330 lbs total - enough for additional pair of .50s. The B series engine should give enough of extra oomph, to cater for extra protection, but as always, Corsair's pilots are best advised not to play the lightweight fighters game.

edit: the term 'armament provision' might also include armor installed??

The armament provision may indeed include armor.

AN F4U-1 with full ammo and internal fuel (363 gallons) was 12656lbs. leave out 185 gallons at 6lb/gal and you get the weight down to 11546lbs. The "full" load of ammo went about 344lbs more than the 200rpg load and the oil tank was given another 8 gallons of oil when the fuel tanks were full to make up the difference (60lbs)

There is a a bit of confusion in the inscription as most sources give ONE .30 cal and ONE .50 cal as the cowl guns in the XF4U-1 and even the early Brewster Buffaloes only carried a single .30 cal gun in the cowl paired with a single .50 cal.

125lbs is not enough for a pair of .30 cal guns (44-50lbs?) even with 5-600 rounds per gun (another 60-72lbs?) and yet is not enough for a .30 and .50 with ammo although it might be enough for the guns, mounts, ammo boxes and chutes?
Buffalo lists 108 lbs for the mismatched pair of guns without ammo.

 

[tomo pauk]

The 'Detail scale' book about F4U states 2 cowl .30s, each with 750 rounds.