Findings Led FAA To Reduce Blade Life Limit To 3,000 Hours

The National Transportation Safety Board has determined a fatigue failure of a turbine blade brought down a tour helicopter in Hawaii last year.

A Sunshine Helicopters Eurocopter AS350BA crash-landed onto a canopy of trees on January 10, 2006 in Maui, after departing Kahului Airport for a one hour sightseeing tour.

According to the NTSB probable cause report, the helo was coming out of Manawainui Gulch near Kaupo following a viewing of Haleakala Crater when "the helicopter vibrated, shuddered, and the low rotor rpm warning horn sounded."

The pilot entered an autorotation and set it down into a canopy of trees on its right side, according to the report. All aboard were able to lower themselves to the ground and call for help.

The NTSB investigation revealed a turbine blade from the second stage gas producer turbine had separated from the turbine wheel, a result of a fatigue fracture caused by a corrosion/oxidation pit.

As a result of this investigation, the Federal Aviation Administration and engine manufacturer Turbomeca reduced the life limit of the second stage turbine blades from 6,000 hours to 3,000 hours and implemented additional turbine inspection criteria.

The part in question in this accident had been in service 2,986 hours and had been used as a replacement part during a 2004 overhaul.

According to the Honolulu Advertiser, Sunshine Helicopters' Ross Scott said the NTSB report gives the company "a clean bill of health."

The pilot sustained a broken ankle, but his four passengers walked away without serious injury.

FMI: Read The NTSB Probable Cause Report