§ Mr. Neaveasked the Secretary of State for Defence whether he will make a statement on the accident to a Whirlwind of the Queen's Flight on 9th December, 1967.
§ Mr. Merlyn ReesI should like to take this opportunity of expressing publicly my sympathy with the families of those who lost their lives in the accident.
Inquiry proceedings in regard to this accident are now complete.
The Board of Inquiry has established that the accident was due to a fracture of the main rotor shaft caused by fatigue cracking which arose from grinding burns during the process of manufacture. These burns caused minute cracks to develop which were not detected by the approved inspection processes in use at that time. The Board considers that no blame attaches to the Royal Air Force. The area where the failure occurred is not accessible in service and is not reinspected except during overhaul.
As a result of this finding the Ministry of Technology has prescribed new crack detection techniques and procedures 184W which are considered to provide an effective safeguard against similar failures in future. All Whirlwind rotor drive shafts in service have been re-examined with the aid of these new techniques and a number of shafts have been rejected as unsatisfactory. There is, however, no evidence to show that these defects would have led to shaft failure. New shafts have been fitted as necessary and those which have passed the test have been reissued to the Service. All front line Whirlwinds in the Royal Air Force are now flying again.
Plans were well advanced before the accident for the Whirlwinds in The Queen's Flight to be replaced by more modern twin-engined Wessex helicopters. These plans will be put into effect as soon as possible. In the meantime the remaining Whirlwind of The Queen's Flight will remain in service.