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The pilot had purchased the aircraft some time prior to the accident and did not fly it until he had completed a full training course on gyroplanes of some 7-8 hours. Since completing the training, the pilot had flown about ten hours on type, mainly on windmill inspections on the property. The witnesses to the accident reported that the pilot had taken off on a windmill inspection and they had seen him return about 15 minutes later. As they watched from about one kilometre away, they saw the pilot approach the landing area at about 400 feet above ground level and commence a turn. The aircraft was then seen to nose over and continue in a dive until it struck the ground and exploded on impact. The South Australia Rotor Club was co-opted to assist with the investigation and through their assistance it was learned that this type of gyroplane was fitted with a large pilot cabin that extended some two feet in front of the rudder pedals. Other pilots have reported that this fitment induced severe pitchdown in flight and/or severe yawing due to the imbalance of the airloads on the cabin compared to the correctional force available from the moments of an unmodified empennage. In effect, the anti-yaw moment from the rudder and fin is insufficient and the aircraft is without an effective horizontal stabiliser for effective anti-pitch control. A reduction of power at the onset of any perceived instability would be instinctive and would also reduce a pilot's ability to control the yaw due to the reduced propeller wash over the rudder and fin. The conclusions drawn from the investigation were that the pilot experienced a pitchdown and/or yaw in flight that resulted in the imposition of negative g forces. These forces caused the retreating main rotor blades to dip and strike the fin and rudder. At the same time, the propeller would have disintegrated on contact with the rotor blades as they dipped into its arc. The blade strikes were such as to to stop the main rotor and put the aircraft beyond the control of the pilot.

Download Final Report
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General details
Date: 03 December 1989 Investigation status: Completed 
Time: 1510  
Location:20 km NE Kingston Investigation type: Occurrence Investigation 
State: South Australia Occurrence type: Loss of control 
Release date: 26 April 1990 Occurrence class: Operational 
Report status: Final Occurrence category: Accident 
 Highest injury level: Fatal 
Aircraft details
Aircraft manufacturer: JRM Helyplanes 
Aircraft model: Wasp Air Buggy II 
Type of operation: Private 
Damage to aircraft: Destroyed 
Departure point:Mt Scott HS, SA
Departure time:1455
Destination:Mt Scott HS, SA
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Last update 21 March 2016