On August 18, 1990, a Mooney M20B (registration N74745) was involved in an aviation accident near Winfield, KS. Investigators recorded the probable cause as: NON-COMPLIANCE OF AN AIRWORTHINESS DIRECTIVE BY MAINTENANCE PERSONNEL. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During landing rollout, the left main landing gear collapsed, causing the airplane to depart the left side of the runway. Investigation revealed the retracting truss failed at a weld.
Incident Details
During the landing rollout, the left main landing gear collapsed, leading the airplane to depart the left side of the runway.
Examination Findings
Examination of the airplane revealed that the left main gear retracting truss failed at a weld, which allowed the gear to collapse. The failed part had been obsolete since the issuance of Airworthiness Directive (AD) 73-21-01. AD 73-21-01 directed the replacement of retracting links on Model M20 airplanes and referenced Mooney Service Bulletin M20-155.
Maintenance History
The service bulletin further specifies that this aircraft, by serial number, requires replacement of the retracting trusses to utilize the new links. The airframe log showed that the AD had been signed off with the notation "new retract links" installed. Additionally, the right main and nose gear trusses were also original and obsolete.