AAIB investigation to Robinson R66, G-LROK

Dynamic rollover during takeoff, Denham Airfield, Buckinghamshire, 12 September 2015.


The student pilot had commenced training for his PPL(H) on the R44, in which he had flown solo, before changing to the R66 some 18 flying hours before the accident flight.

On the day, he completed five dual circuits with his instructor. They then landed and the instructor exited the helicopter, to allow the student to conduct his first solo flight on the R66. As the student lifted into the hover, the helicopter rolled right and the rotors struck the ground. The helicopter came to rest on its side and the student, who sustained minor injuries, was able to vacate the cabin. The instructor, who was standing 50 yards away, commented that it appeared a dynamic rollover had occurred.

In 1982 the Robinson Helicopter Company issued Safety Notice SN-9, concerning dynamic rollover . It states:

‘A dynamic rollover can occur whenever the landing gear contacts a fixed object, forcing the aircraft to pivot about the object instead of about its own center of gravity…Once started, dynamic rollover cannot be stopped by application of opposite cyclic alone…Quickly applying down collective is the most effective way to stop dynamic rollover.’

Download report:

Robinson R66, G-LROK 02-16

Download glossary of abbreviations:

Glossary of abbreviations

Published 11 February 2016