Accident Overview
On April 3, 2012, at approximately 1555 central daylight time, an Enstrom 280FX helicopter, registration N3042D, operated by Travland Helicopters Intl INC., sustained substantial damage during a hard landing at Corpus Christi Airport (CRP) in Corpus Christi, Texas. The commercial pilot received minor injuries, while the passenger was not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The business flight, conducted under 14 CFR Part 91, had originated from Edinburg, Texas, with Corpus Christi as its intended destination.
Flight and Incident Sequence
After an uneventful flight from Edinburg, the pilot set up for landing at CRP. Slowing the helicopter into a stable hover approximately 15 feet above the landing point, the rotor RPM suddenly decayed, causing the helicopter to land hard. The main rotor drive was lost without warning, and the helicopter was in a position where power to the rotor system was essential for a safe landing. The pilot, who had over 5,600 hours of helicopter flight experience, reported no prior indications of a malfunction.
Examination Findings
An FAA inspector examined the helicopter and discovered that the bolt retaining the clutch drive rod end in the clutch pivot fork had sheared. The pivot fork ears exhibited wear on the inside but were not bent, and the rod end to the clutch drive was not bent. The bolt was elongated, the pivot fork bushing was worn, and the head of the bolt was missing. Examination of the entire drive system revealed no preexisting mechanical malfunctions or abnormalities. The bolt was the correct hardware for the installation, and it was the original component, with the helicopter having accumulated approximately 1,350 hours since new.
Conclusion
The hard landing resulted in substantial damage to the tailboom. The investigation determined that the loss of rotor drive was caused by the shearing of the bolt that retains the clutch drive rod end in the clutch pivot fork.