






[/center]Moderators: wdolson, Don Bowen, mogami







[/center]
[/center]









In 1938, Richard W. Palmer started the detailed design of the V-48 fighter member of the quartet. The aircraft featured a metal covered, semi-monocoque fuselage and fully retractable landing gear powered by a Pratt & Whitney R-1830 radial air-cooled engine. During construction of the first prototype, a decision was made to lengthen the propeller shaft and install a tight cowling to provide a pointed nose to reduce drag. The first aircraft flew in September 1939, and was assigned registration number NX21755. The fighter was named the Vanguard.
Flight tests revealed the aircraft was suffering from inadequate cooling. Measures to modify the cooling ducting were of little avail. After re-evaluating the design, and noting that the insignificant drag decrease was not worth the added weight and ducting problems, the second prototype, which was assigned the model number V-48X and registration NX19999, was modified with a conventional cowl and the first aircraft were similarly modified. The second aircraft first flew on 11 February 1940. As a result of flight tests, a number of changes were made to the design including substantially increasing the areas of the horizontal and vertical tail surfaces.