Bell XP-39E Airacobra
The XP-39E was an experimental version of the Airacobra originally produced as a test bed for the Continental V-1430 engine. This engine failed to appear, and so the three XP-39Es were powered by the Allison V-1710-47 (E9). This engine was one of a number of versions of the V-1710 to be given a two stage mechanical supercharger (the same technology as used in the Rolls-Royce Merlin). As a result the XP-39E had much better high altitude performance than any version of the P-39 apart from the turbo-supercharged XP-39, with a top speed of 393mph at 24,000ft.
The XP-39E is often said to have had a laminar flow wing, as used in the P-63 Kingcobra, but this does not appear to have been the case. Instead each of the three XP-39Es used a slightly different wing. The XP-39E was significantly heavier than standard P-39s, with a gross weight of 9,000lb.
Originally two XP-39Es were ordered. The first aircraft made its maiden flight on 26 February 1942, but was lost in a crash on 26 March 1942 (from which the pilot escaped). After this crash a third prototype was ordered. The second aircraft made its maiden flight on 4 April 1942, and itself suffered serious damage on 11 May 1942.
Two days before the XP-39E made its maiden flight an order was placed for 4,000 of the new aircraft, with the designation P-76. This order was cancelled on 20 May 1942 before any aircraft had been built, and the factory space saved was used to built the B-29 Superfortress.
Bell P-39 Airacobra, Robert F. Dorr with Jerry C. Scutts (Crowood Aviation). A detailed looked at the development and service history of this controversial American fighter aircraft. The P-39 had a poor reputation amongst British and American pilots, and Dorr examines the reasons why, as well as looking at why the same aircraft was so much more popular in Soviet Service. Scutts provides a chapter on the P-63 Kingcobra, and the book also covers the numerous Bell fighter projects that failed to enter production.
Bookmark this page: 
Delicious 
Facebook 
StumbleUpon
How to cite this article:
Rickard, J (7 July 2008),
Bell XP-39E Airacobra , http://www.historyofwar.org/articles/weapons_XP_39E.html
