On touchdown the left main landing gear collapsed. The cause of the collapse was failure of both upper torque link attachment lugs on the landing gear cylinder due to fatigue cracking. There is a known history of fatigue cracking on cast landing gear cylinders and a manufacturer’s Service Bulletin exists to regularly inspect the area around the attachment lugs. There is currently no Airworthiness Directive to mandate the Service Bulletin.
One Safety Recommendation is made to the CAA to ensure that the level of safety of cast main landing gear cylinders fitted to PA-28 and PA-32 aircraft is acceptable.