On February 6, 1984, a Grumman American AA-5B (registration N81317) was involved in an aviation accident near Lake Havasu Cit, AZ. Investigators recorded the probable cause as: Failure of the mounting bolts due to overstress. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During cruise at 8,500 feet MSL, the propeller assembly separated from the aircraft. In the forced landing rollout, the aircraft struck a tree. The remaining portion of broken mounting bolts showed signs of overstress failure.
Incident Summary
While in cruise at 8,500 feet MSL, the propeller assembly forward of the mounting flange separated from the aircraft. The pilot executed a forced landing, during the rollout of which the aircraft struck a tree.
Investigation Findings
Investigators examined the remaining portion of the broken mounting bolts. These bolts showed signs of failure due to overstress. The propeller itself was not recovered.
Maintenance and Directive Compliance
Airworthiness Directive 82-27-01 required inspection of the propeller hub and mounting bolt hole areas for cracks. No record of compliance with this directive was found. However, an annual maintenance inspection had been performed on June 8, 1983.