On September 24, 1992, a Grumman AA-1A (registration N6445L) operated by Martill Inc. was involved in an aviation accident near Bedford, MA. Investigators recorded the probable cause as: The rudder cable separated at the fuselage pulley due to extensive fatigue cracking in the individual wires, leading to a loss of directional control. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot lost directional control after liftoff when the rudder cable failed due to fatigue cracking. The airplane rolled right, struck the ground, and came to rest inverted.
Accident Overview
During takeoff, shortly after lifting off, the pilot experienced a loss of directional control. The airplane rolled to the right, and the right wing struck the ground. According to the pilot, rudder authority was abruptly lost. The airplane subsequently impacted the ground and came to rest inverted.
Contributing Conditions
At the time of the takeoff, a 10-knot quartering tailwind was present. An examination of the airplane revealed that the rudder cable had separated at the fuselage pulley. Metallurgical examination of the separated cable showed extensive fatigue cracking in the individual wires.
Maintenance History
A review of maintenance records indicated that Airworthiness Directive 72-06-02 required recurrent inspections of the rudder cable every 100 hours. Compliance with this AD was documented at the last annual inspection. Since that inspection, the airplane had been operated for approximately 65 hours.
Probable cause
The rudder cable separated at the fuselage pulley due to extensive fatigue cracking in the individual wires, leading to a loss of directional control.