On August 20, 2002, a Schweizer 269C (registration N7508L) operated by Rotors OF The Rockies was involved in an aviation accident near Broomfield, CO. Investigators recorded the probable cause as: maintenance personnel's failure to secure the landing skid oleo strut bolt during the last 50-hour inspection, causing the left rear skid to collapse and the tail rotor to strike the ground. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 1 related events involving the same aircraft type or operator are linked below.
During autorotation practice for a helicopter practical test, a loud noise preceded the helicopter settling, causing tail rotor strike. Missing bolt on left rear oleo strut attachment found.
Accident Description
A student pilot was practicing autorotations in preparation for a rotorcraft-helicopter practical flight test scheduled the following day. An instructor was onboard. The student had successfully completed two "full down" autorotations. During the third autorotation, a loud noise was heard, and the helicopter settled toward the left rear side, resulting in the tail rotor striking the asphalt taxiway.
Postaccident Inspection
Postaccident inspection revealed that the bolt attaching the left rear oleo strut to the crossbeam was missing. The tail rotor blades were damaged, the tail rotor driveshaft was twisted, and the splined end of the driveshaft had separated from the main transmission.
Maintenance History
Maintenance records indicated that the helicopter had accumulated 5.1 hours since the last 50-hour inspection. During that inspection, the landing gear struts had been overhauled and the skid shoes had been replaced.