What happened
On 17 September 2010, an Auster 4, registration G-ANHS, was performing a private flight when the pilot encountered engine issues while joining the landing circuit at RAF Cottesmore. During the approach, the pilot followed standard operating procedures by switching the fuel selector from the belly tank to the main tank. Following this selection, the engine immediately faltered and appeared to cut out. An attempt to rectify the issue by reselecting the belly tank was unsuccessful.
As the engine failure progressed and the propeller ceased rotation, the aircraft experienced a marked increase in its rate of descent. The pilot declared an emergency with Cottesman Tower and was granted immediate clearance to land on Runway 22. The aircraft subsequently made a heavy landing, which resulted in the collapse of the landing gear and damage to the wing struts. There were no injuries to the pilot or the passenger, and both occupants were able to exit the aircraft without assistance.
The investigation
The investigation examined the sequence of events leading to the engine failure and the subsequent landing. The pilot noted that approximately 7 gallons of fuel remained in the tanks at the time of the incident. The investigation focused on the transition between fuel tanks and the mechanical behavior of the engine during the selection process.