History of Flight
On 24 November 2014, the pilot, who also owned the helicopter, had the aircraft flown to an approved maintenance organisation (AMO) to rectify an engine oil leak caused by a crankshaft seal. After replacement, the engine was accidentally started without oil, leading to its removal and overhaul. The overhauled engine was returned to the AMO and installed in the airframe on 24 March 2015. Ground runs and a post-maintenance test flight were conducted, and on 25 March 2015 the helicopter was delivered to the owner.
On 2 April 2015, the owner flew a local flight of about 12 minutes. The following morning, 3 April 2015, the pilot departed from his helipad with a passenger for a private flight to the Verulam Recreational Grounds. The intended landing was a static display. While orbiting the field at approximately 400 feet above ground level (AGL), waiting for a vehicle to be moved, the engine failed. The pilot reported no warning lights or instrument fluctuations before the failure.
He identified a nearby polo field for landing, requiring a 180° turn. During the approach, main rotor RPM decayed and the low rotor RPM audio warning and caution light activated. The pilot stretched the autorotation to clear surrounding trees. The helicopter touched down hard, remained upright momentarily, then rolled onto its right side, coming to rest semi-rolled over with one main rotor blade embedded in the soil.
Injuries to Persons
The passenger, seated in the left front seat, sustained a back injury and was admitted to hospital. The pilot suffered a laceration to his left elbow.
Damage to Aircraft
The helicopter sustained substantial damage during the impact sequence. The front cross tube assembly separated from the fuselage. No other damage occurred.
Probable Cause
The investigation determined the probable cause to be an unsuccessful forced landing following an engine stoppage in flight attributed to a loose fuel pipe that supplies fuel from the fuel control unit (FCU) to the fuel flow divider.