History of Flight
The pilot departed Wonderboom Aerodrome (FAWB) at approximately 0550Z on a private visual flight rules (VFR) day flight to the Pretoria general flying area and back. The pilot was the sole occupant. The flight was uneventful until the landing phase. After contacting ATC, the pilot received clearance to land on Runway 29. During the landing roll, the right main landing gear oleo failed, causing the aircraft to veer left. The pilot applied right rudder and reduced engine power to maintain directional control. The aircraft left the runway to the left after approximately 710 meters of landing roll, coming to rest on grass about 18 meters from the runway edge. The nose wheel separated during the excursion. The aircraft sustained substantial damage; the pilot was not injured.
Aircraft Information
The accident aircraft was a Piper PA-28-140, serial number 28-7625069, manufactured in 1976. It was powered by a Lycoming O-320-D2A engine. The total airframe time at the time of the accident was 9130.06 hours. The last mandatory periodic inspection (MPI) was completed on 31 March 2010 at 9042.81 hours, and a 50-hour progressive inspection was carried out on 7 May 2010. The aircraft documentation was found to be valid.
Landing Gear Defects
A recurring defect with the right main landing gear oleo strut was recorded in the flight folio. Seven entries between 8 January and 15 April 2010 noted the oleo as flat. Corrective actions included replacing seals and recharging with compressed air and hydraulic fluid. On one prior occasion, the oleo failed during a landing roll, necessitating maintenance. Visual inspection after the accident indicated the oleo was bottoming, with loss of shock absorber effect. The manufacturer specifies a required piston tube exposure of 4.5 ± 0.50 inches under normal static load.
Meteorological Information
At the time of the accident, the wind was from 290° at 9 knots, temperature 16°C, dew point 8°C, CAVOK conditions, and good visibility. The METARS had indicated light and variable surface wind earlier.
Pilot Information
The pilot, aged 29, held a valid private pilot licence with a single-engine piston rating. Total flying experience was 104.4 hours, with 28.5 hours on type.
Injuries and Damage
No injuries were reported. The aircraft sustained substantial damage. There was no other damage to property.
Probable Cause
The aircraft landed deep on the runway due to strong and unexpected tail wind conditions prevailing at the threshold of runway 29 and combined with failure of the right hand oleo resulted in a runway excursion.