F4UDOA,
Howdy pard.
A few months back you graciously e-mailed me a copy of some performance data from the F6F-5 pilot's manual published by Grumman. In one table, performance figures were for the fighter were listed for normal power, military power, and war emergency power under normal, overload, and fighter bomber weight conditions. The critical altitude for the R2800 appeared to be between 22,000 and 23,000 feet regardless of loadout.
In previous posts we have already discussed the performance discrepancies evident between the Hellcat's airspeed indicator and its actual speeds. It is not my purpose to beat that dead horse again. Let me make a few observations and then follow on with some questions.
Many sources list the F6F-5's top speed at 380mph. That appears to be the most commonly accepted figure. The only figure listed on the table provided by the pilot's manual comes under the conditions of fighter overload (12,483 pounds) at 23,000 feet under normal power. However, according to the table, the actual top speed of the -5 is 401mph at a fighter normal weight of 11,494 pounds at 20,000 feet.
The top speed of the experimental XF6F-6 with the R2800-18w engine is 417mph. That is 37mph faster than the 380mph that is usually listed as the Hellcat's top speed. That substantial increase in performance jibes well with some comments I have read over the years about the great boost in performance that the R2800-18w bestowed on the Hellcat. The performance gain was supposed to approximate the gains of the F4U-4 over previous models of the Corsair.
Follow me so far? My first question is this...Is the 417mph speed figure for the XF6F-6 under normal or war emergency power? Secondly, if the 37mph performance gain is accurate, and the 401mph figure for the -5 was the true top speed of the -5 Hellcat, wouldn't the actual top speed of the XF6F-6 have been 438mph under war emergency power?
Are there any sources where the data for these aircraft can be checked?
Appreciate any help you can give me on this.
Regards, Shuckins
