I agree that the documentation is vague and there may be some confusion over different speeds at different altitudes and conditions. However, according to a NACA/NACA history
http://www.hq.nasa.gov/pao/History/SP-468/ch5-3.htm (Quest for Performance: The Evolution of Modern Aircraft), it states the following:
"Indeed, the P-38 was a high-performance aircraft. Even the prototype exceeded 400 miles per hour in 1939."
There may be another explanation for why the Corsair did not immediately achieve a speed exceeding 400: the XF4U-1 first flew on 29 MAY 1940 but it would not be until September of that year that BuNo 1443 would undergo NACA FST (Full Scale Tunnel) wind tunnel testing designed to smooth out the aerodynamics and tweak the design for its best drag profile. NACA was initially asked to do this for the Brewster XF2A Buffalo and the military was so amazed at the startling improvement in speed that NACA was soon swamped with requests to test and refine a large number of both USAAF/USN/USMC designs, including the XF4U-1. In 1942, a production model F4U-1 would also be tested. The Brewster Buffalo was never assigned a number for its "order of receipt" at Langley but arrived between those assigned numbers #114 and #115. The XF4U-1 was assigned Receipt No. 172 and the YP-38 (#2 - AC39-690) was received as the 177th test aircraft. (http://www.hq.nasa.gov/office/pao/History/SP-468/app-e.htm)
I agree that the documentation is vague and there may be some confusion over different speeds at different altitudes and conditions. However, according to a NACA/NACA history
ReplyDeletehttp://www.hq.nasa.gov/pao/History/SP-468/ch5-3.htm (Quest for Performance: The Evolution of Modern Aircraft), it states the following:
"Indeed, the P-38 was a high-performance aircraft. Even the prototype exceeded 400 miles per hour in 1939."
There may be another explanation for why the Corsair did not immediately achieve a speed exceeding 400: the XF4U-1 first flew on 29 MAY 1940 but it would not be until September of that year that BuNo 1443 would undergo NACA FST (Full Scale Tunnel) wind tunnel testing designed to smooth out the aerodynamics and tweak the design for its best drag profile. NACA was initially asked to do this for the Brewster XF2A Buffalo and the military was so amazed at the startling improvement in speed that NACA was soon swamped with requests to test and refine a large number of both USAAF/USN/USMC designs, including the XF4U-1. In 1942, a production model F4U-1 would also be tested. The Brewster Buffalo was never assigned a number for its "order of receipt" at Langley but arrived between those assigned numbers #114 and #115. The XF4U-1 was assigned Receipt No. 172 and the YP-38 (#2 - AC39-690) was received as the 177th test aircraft. (http://www.hq.nasa.gov/office/pao/History/SP-468/app-e.htm)