Accident Overview
On 30 May 2018, at approximately 1004Z, a Piper PA-31-350 (registration ZS-LVJ) sustained substantial damage when the left main landing gear collapsed during the landing roll at Wonderboom Aerodrome (FAWB). The aircraft had departed Baragwanath Aerodrome (FASY) on a private ferry flight under Part 91. The pilot and two passengers were on board; no injuries were reported.
Flight Details
The flight to FAWB was uneventful. During approach, the pilot selected the landing gear down and received green indication lights confirming the gear was locked. The aircraft touched down on Runway 29 under visual meteorological conditions (wind 290° at 10 knots, temperature 22°C, visibility 10 km). During the landing roll, the left wing began to drop. The pilot suspected a left main gear failure, closed the throttles, placed mixtures to idle cut-off, and feathered the propellers. The aircraft veered left onto the grass. The pilot shut down the fuel and master switch, and the occupants evacuated without injury.
Damage and Inspection
The aircraft sustained substantial damage to the left propeller and left wing. Post-accident examination revealed that the left main landing gear side brace (part number 40277) had fractured at the pivot point. The left wing tip and flap were damaged from ground contact. The right main gear components showed no discrepancies. The landing gear rigging and bushings were found satisfactory.
Metallurgical Findings
The fractured side brace was examined by a metallurgist. The fracture surface exhibited features consistent with fatigue, including curving crack arrest lines and ratchet marks indicative of multiple fatigue origins. The fatigue region was relatively small compared to the remainder of the fracture area, consistent with high cyclic stresses. The overstress portion of the fracture showed features consistent with ductile overload.
Maintenance History
Maintenance records indicated compliance with FAA Airworthiness Directive (AD) 2000-25-01 on 7 April 2008 and AD 96-10-14 on 29 May 2014, 13 October 2017, and 16 August 2018. However, the aircraft maintenance organization could not provide records demonstrating actual dye penetrant inspections of the left and right main landing gear forward side braces, as required by AD 96-10-14; only logbook entries were available. The aircraft's most recent mandatory periodic inspection was completed on 5 February 2018 at 8081.1 total airframe hours. Following that inspection, 46.5 hours were flown before the accident.
Pilot Information
The pilot held a valid commercial pilot license and medical certificate at the time of the accident (license issued 22 April 2017, expiring 31 May 2018; medical issued 17 November 2016, expiring 31 October 2017). He had accumulated 4958.5 total flight hours, including 100 hours on the Piper PA-31-350.
Probable Cause
The left main landing gear collapsed due to a fractured MLG side brace.