NACA group worked closely with flight test engineers and in fact took part in discussing NACA's flying qualities work with outsiders. All of this helped lay the groundwork for the comprehensive flying qualities research that followed." By 1932, Allen was a highly respected independent test pilot and consulting aeronautical engineer. As a freelance pilot, Allen was the first to fly Boeing airplanes, Douglas airplanes, Northrop airplanes and other airplanes. Below is a list of airplanes flown by Allen: Boeing Model 83, the forerunner of the famous Boeing F4Bs and Boeing P-12s (25 June 1928) Northrop Alpha (March 1930) Boeing Monomail (22 May 1930) Northrop Beta (3 March 1931) Northrop Gamma (1932) Stearman 80 (10 April 1933) Douglas DC-2 (11 May 1934) North American NA-16 (1 April 1935) Sikorsky S-43 (5 June 1935) Spartan Executive (8 March 1937) Sikorsky XPBS-1 (14 August 1937) Boeing XB-15 (15 October 1937) Boeing 314 Clipper (7 June 1938) Boeing 307 Stratoliner (31 December 1938) He was also involved in the test flying of the Douglas DC-1 and the Consolidated XPB2Y-1. World War II In April 1939, Boeing gave Allen a permanent position as the head of the company's Research Division, and direct charge of all flight testing and of aerodynamics and wind tunnel research. In this position, he made the first flights of the: Boeing Stearman X-100 (XA-21; 25 January 1939) Boeing XPBB Sea Ranger (9 June 1942) Boeing B-17B (27 June 1939) Boeing B-17C (21 July 1940) Boeing B-17D (3 February 1941) Boeing B-17E (5 September 1941) Boeing B-17F (30 May 1942) Boeing XB-29 Superfortress (21 September 1942) Even his position at Boeing did not stop the Army Air Force from borrowing Allen for the first flight of the Lockheed C-69 Constellation on 9 January 1943. He also piloted the first flight of the Curtiss-Wright CW-20 on 26 March 1940. Allen did not fit the image of the daredevil test pilot Hollywood promoted. He was very slender, and some described him as frail. He considered himself an engineer as well as a pilot, and insisted the test pilot should be involved in the development of new aircraft, not just fly them. Allen developed a systematic approach to flight testing and set standards that are the basis for modern flight testing. He also formed a dedicated flight-test and aeronautical research organization at Boeing and insisted that the company develop its own high-speed wind tunnel, an