Incident Overview
A helicopter experienced an in-flight separation of the lower portion of its left engine cowling. The pilot and passenger were not injured. The aircraft returned to its departure airport, located 45 miles away, for an uneventful landing.
Witness Account
A witness on the ground observed the helicopter in flight and saw several pieces fall from the aircraft. The debris subsequently landed in the witness's yard and a neighbor's yard.
Pilot Report
The commercial pilot stated that while in enroute cruise at approximately 1,500 feet above ground level, he felt a "bump on the controls" and heard a "bang." He initially believed he had struck a bird. The pilot returned to the departure airport for an otherwise uneventful landing.
Post-Flight Inspection
After landing, the pilot discovered that the lower portion of the left engine cowling was missing. Evidence indicated that the cowling pieces had struck both main rotor blades and both tail rotor blades. Substantial damage was found to the left engine cowling, both tail rotor blades, the tail rotor yoke, and the tail rotor gearbox. No bird remains were located.
FAA Examination
An FAA inspector examined the helicopter and the separated cowling pieces. The inspection found no evidence of bird remains and no damage to the cowling latches that would have prevented them from operating normally prior to the accident.