Date & Time: Dec 3, 1945
Operator:
Registration:
G-AGSS
Flight Phase:
Takeoff (climb)
Flight Type:
Test
Survivors:
No
Schedule:
Radlett - Radlett
MSN:
68/1
YOM:
1945
Region:
Europe
Crew on board:
2
Crew fatalities:
2
Pax on board:
0
Pax fatalities:
0
Other fatalities:
0
Total fatalities:
2
Circumstances:
First prototype of the Hermes, this model H.P.68 (s/n 68/1) was later renamed H.P.81. Both crew members left Radlett Airfield to complete the first test flight on this new airplane. Few minutes after takeoff, while cruising in the vicinity of the aerodrome, the four engine aircraft went out of control and crashed in a field located 5 km from the airport. Both occupants were killed.
Probable cause:
Investigators considered that the accident was the direct result of elevator overbalance, this brought about flight conditions the nature of which caused the pilot to lose control. Although the porpoising motions set up by the overbalanced elevators would have been expected, the final manoeuvre of the aircraft, in climbing suddenly, cannot be satisfactorily explained. It seems certain, however, that at different trimmer settings, a reversal of stick forces would have occurred with which the pilot could not have kept in phase as the loads increased.