This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information.
Accident investigation report completed and information captured
Narrative: Wallis WA-117 Autogyro G-AXAR: Written off (destroyed) 11/9/1970 when crashed whilst performing a demonstration flight at the 1970 Farnborough Air Show. The pilot, John W. Charles "Pee Wee" Judge (aged 48, at the time the Chief Test Pilot of Beagle Aircraft) was killed. According to the following summary from the official report into the accident:
"The aircraft was being demonstrated at the Society of British Aerospace Companies (SBAC) air show at Farnborough. After a high speed downwind run parallel to the runway the aircraft first pitched rapidly nose-up, then nose-down, and went out of control, the rotor blades striking the propeller, fin and rudder as it fell to the ground. The pilot was killed instantly.
The report concludes that the accident resulted from a loss of control due to the effect of negative 'g' when the pilot attempted to control a nose-up pitch that occurred during a manoeuvre in which the aircraft's speed exceeded the authorised maximum."
The accident report can be summarized as follows.
1. G-AXAR just before the accident was flying at some 92 knots EAS and at that speed a relatively small relaxation of the push force required to maintain level flight such as to allow the control column to move aft one inch, could account for the last steep portion of the climb. To recover, the aircraft could have been flown out of this manoeuvre by increasing the bank angle and executing a “wing over” to maintain positive “g”. In the event the pilot moved the control column rapidly forward.
2. Once full forward control had been applied and sustained for approximately one second the aircraft was pitched rapidly nose-down the pilot would expect to try to counteract the motion as soon as the aircraft appeared to him to have recovered from the steep nose-up attitude which had caused him to move the control column forward in the first place. Some 4.76 seconds before impact the rotor head did, in fact, tilt fully back indicating that the pilot had moved the control column fully aft. However, the rotor rpm had by this time started to fall, negative “g” having unloaded the rotor, and as a result of the consequent reduction in control effectiveness the aircraft did not respond, continued to pitch nose-down until it reached the vertical and the rotor blades came into contact with the aircraft structure.
Theoretical instability analysis of the aircraft, without a tail plane showed a marked instability “stick fixed” as speed increased. This instability was not so noticeable in practice below 65 knots because of a contribution from the aircraft’s markedly stable “stick free” characteristics in which forces present at the control column tended to move the pilot’s hand in the correcting direction.
4. Some quantitative improvement in “stick fixed” stability resulted when the aircraft was fitted with an experimental tail plane.
5. Cause: The accident resulted from a loss of control due to the effect of negative “g” when the pilot attempted to control a nose-up pitch which occurred during a manoeuvre when the aircraft was flying at a speed in excess of the authorized maximum.
6. With no tail plane, flight tests indicated that the aircraft was unstable in pitch when the control column was mechanically locked (stick fixed).
7. With tail plane, the aircraft appeared to be stable “stick fixed.” For other conditions, stick free and no tail plane, the aircraft appeared to be stable with possibly slightly increased damping of the short period oscillation
Registration G-AXAR cancelled by the CAA as aircraft "destroyed" 11/9/1970. Ken Wallis withdrew all his autogyros from use by anyone other than himself, after the crash of WA-117 G-AXAR at the 1970 Farnborough Air Show.