Wednesday, May 4, 2011
Safety Recommendations Issued For Eurocopter
The National Transportation Safety Board (NTSB) is recommending the FAA require Eurocopter to revise its aircraft maintenance manual for all helicopters equipped with part number 355A11-0020 and/or 355A11-0030 main rotor blades to include, as part of the daily flight-related check, specific visual inspections of the trailing edge of the blades and upper and lower skin surfaces for cracks and surface deterioration/disfiguration. The Safety Recommendation (A-11-35) was issued May 3.
Once the Eurocopter manual is revised, NTSB is recommending (A-11-36) that the FAA require operators of all Eurocopter helicopters equipped with above mentioned part number main rotor blades to revise their maintenance manuals to include specific daily visual inspections of the trailing edge of the blades' upper and lower skin surfaces for cracks and surface deterioration/disfiguration.
“The NTSB's recommendations come out of its investigation of a July 7, 2007 accident involving a Eurocopter EC-130-B4 (N453AE) helicopter. The aircraft operated by Liberty Helicopters, Inc. experienced an in-flight separation of a section of one of the main rotor blades. No injuries were reported among the eight people on board.
The safety board determined that the probable cause of this accident was the fatigue fracture and in-flight separation of a section of the composite main rotor blade trailing edge aft of the spar, due to inadequate manufacture, and the manufacturer’s failure to detect an out-of-specification deviation in the rotor blade’s trailing-edge roving, a collection of fibers in a parallel bundle with little or no twist.