What happened
On the morning of 3 0 May 2018, a Piper PA-31-350 Navajo Chieftrain, registration ZS-LVJ, was conducting a ferry flight from Baragwanath Aerodrome to Wonderboom Aerodrome for maintenance purposes. The flight, which was being operated under Part 91 regulations, proceeded normally through the initial climb and cruise phases.
During the approach to Runway 29 at Wonderboom, the pilot confirmed the landing gear was down and locked. While the aircraft touched down on the centerline at approximately 60 knots, the left main landing gear collapsed during the landing roll. The sudden failure caused the left wing to drop, leading the aircraft to veer off the runway onto the grass. The impact caused the left propeller and wing to strike the ground, resulting in substantial damage to the aircraft. There were no injuries to the pilot or the two passengers on board.
The investigation
SACAA AIID investigators examined the wreckage and the aircraft's maintenance history to determine the cause of the collapse. A physical inspection of the left wheel well revealed that while hydraulic lines and oleo struts were intact, the left main landing gear side brace had fractured. Metallurgical analysis of the part showed features consistent with fatigue at the pivot point, alongside evidence of ductile overstress fracture.
Investigators also reviewed the maintenance records of the aircraft maintenance organisation (AMO) responsible for the aircraft. While the logbooks indicated compliance with Airworthiness Directive (AD) 96-10-14—which mandates repetitive dye penetrant inspections of the landing gear side braces—the AMO could not produce the specific maintenance records to substantiate these entries.
Findings
- The primary cause of the landing gear collapse was a fracture of the left main landing gear side brace.
- The fracture was the result of fatigue and, in certain areas, overstress.
- There was a lack of verifiable evidence that the required dye penetrant inspections mandated by AD 9 6-10-14 had actually been performed.
- The aircraft was within weight and center of gravity limits at the time of the accident.
Safety action
- It is recommended that the AMO ensure strict adherence to manufacturer documentation and civil aviation regulations regarding maintenance records.
- A recommendation was made to the Director of Civil Aviation to review the maintenance activities of the AMO to ensure all logbook entries are supported by verifiable maintenance records.