Foreword

In the mid twentieth century, Bell Aircraft Company's Mach 3 experimental X-2 rocket airplane was an amazing vehicle. The technological challenges that were met and overcome by designers and flight test teams resulted in an impressive vehicle. The story should be recorded in the history of aviation.

The engineers and pilots assigned to the X-2 program were the best flight test and engineering talent available. They were a dedicated and intrepid group of professionals intent on accomplishing the program objectives of aeronautical exploration. The objectives were to fly the X-2 higher and faster than any previous piloted aircraft. This was a spirited, steadfast and resolute team—not capricious or foolhardy. The X-2 program had suffered years of delay due to rocket and flight control technical difficulties and it was time to get on with completing the program objectives. By July 23, 1956, the X-2 flight envelope had been expanded to Mach 2.87 and several problems resulted in pilot difficulties. These piloting problems were items of desired airplane improvement but not felt to be absolutely necessary to accomplish the desired results. These problems included areas of low pitch control effectiveness, adverse aileron yaw, poor dynamic stability and rocket thrust-line misalignment. It was thought that with adequate flight planning, understanding and pilot training, the most serious could be avoided by judicious in-flight handling. The pit-fall was in the form of a possible dynamic instability based on extrapolated aerodynamic data projections at Mach 3 and elevated load factor. This potential pit-fall had been recognized, the problem analyzed, the results discussed, options weighed and piloting techniques developed to avoid any possible precipice. The test team decided that this was one of those calculated risks that were part of the exploratory nature of the task at hand. The decision was made to proceed. Unfortunately, the most pessimistic set of flight conditions and circumstances that could occur did just that on the X-2's flight of September 27, 1956. This flight concluded when the theorized dynamic instability, above Mach 3, was realized with disastrous results — a total loss of pilot control ensued resulting in a fatal crash.

This story is dedicated to those intrepid men and women who participated in the revolutionary X-2 experimental program, pushed man's knowledge beyond the limits, and particularly to those whose careers ended with this airplane. Aviation history needs to remember their contributions and sacrifices. Their program didn't finish in the way they had hoped, but neither did it end in failure.

This brief story of the Bell X-2 was prepared, in part, from an unpublished story written by Mr. Richard E. Day who was an active X-2 program participant. Mr. Day was the designated X-2 engineer at the High Speed Flight Station (HSFS) that was the National Advisory Committee for Aeronautics (NACA) facility at Edwards Air Force Base, California. In 1954, Mr. Day acted in an advisory role to the Air Force who was the responsible test agency for envelope expansion of the X-2 with support from Bell Aircraft. NACA would assume responsibility for detailed high speed flight tests at a later date. In addition to the inspiration to write about the X-2, Mr. Day gave this author permission to use any or all of his unpublished story.

The USAF's Bell Aircraft Co. X-2 triple-sonic rocket-powered experimental research airplane (tail number 6674) on the Mojave Desert's Rogers Dry Lake bed as it appeared in 1956. (Lockheed Martin Aeronautics Co.)

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