On June 8, 2002, a Robinson R22 BETA (registration N7176S) operated by Silver State Helicopters, Llc was involved in an aviation accident near Henderson, NV. Investigators recorded the probable cause as: The pilot's misjudged landing flare during an autorotation, which resulted in a hard landing. The pilot's failure to follow the listed emergency procedures in the rotorcraft flight manual and the partial failure of the rotor system's drive belts were factors. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 2 related events involving the same aircraft type or operator are linked below.
A helicopter made a hard landing during an autorotation after a clutch drive belt failure. The pilot misjudged the flare and did not follow the emergency procedure to pull the clutch circuit breaker.
Event
While maneuvering at about 500 feet above ground level during an aerial photography business flight, the pilot and passenger detected an unusual odor. Approximately 5 seconds later, the pilot felt a jolt and observed the cockpit clutch light illuminate. The pilot initiated an autorotative descent but misjudged the landing flare, resulting in a hard touchdown on level open terrain. The clutch light remained illuminated continuously throughout the event.
Pilot Response
The pilot did not execute the prescribed flight manual emergency procedure of pulling the clutch circuit breaker. Engine power was not lost during the sequence. The pilot allowed rotor rpm to decrease and erroneously entered an autorotation instead of performing an immediate landing while being prepared for a possible autorotative descent.
Wreckage Examination
Subsequent examination of the wreckage revealed that one of the two rotor system drive (vee) belts had broken. The second belt was found intact, with its lower section on the lower pulley in the correct position, but the upper section on the upper pulley was shifted forward by one groove.