20170627008709A

On June 27, 2017 approximately 13:48 local time (PST) an Airbus ec 130-B4 helicopter (N151GC) operated by papillon airways inc (PG9A) on a part 135 on-demand flight departed kbvu. Approximately eleven minutes into the flight the pilot stated that the aircraft experienced engine trouble/loss of engine power while operating at approximately 3000 feet MSL. The pilot entered an autorotation and initiated a left hand turn in an attempt to reach a helipad at approximately his 7 to 8 o?clock position. Upon realizing he was unable to reach the helipad and while approaching several power lines he made control inputs to steer clear, at that time one of the main rotor blades struck and cut one of the power lines. The aircraft came to rest approximately twelve minutes after the departure from kbvu in an upslope attitude. The pilot evacuated the passengers.

The aircraft was recovered during the late hours of June 27th through the early hours of June 28th. Upon recovery the aircraft was taken and stored at kbvu in one of the air carriers additional aircraft hangars. This hangar is currently unused which allowed the wreckage to be isolated and secured until an initial investigation could take place.

On June 28, 2017 at approximately 13:30 hour?s local time, several parties met at the hangar where the aircraft was stored to conduct an initial aircraft review. Those attending included four aviation safety inspectors from the local flight standards district office, the air carrier director of operations, director of maintenance, director of safety, and several maintenance technicians. The engine manufacturer (safran helicopter engines (she)) supplied an accident investigator as well.

Initial visual inspection reflected left hand skid tube bent in the middle as this part of the tube landed on a rock. Additionally the fuselage just forward of the fuselage to tailboom bulkhead, bottom side had ?oil canning?. Lastly initial visual inspection reflected damage to one of the main rotor blades.

Further investigation reflected that the engine was seized. The engine was removed from the aircraft and prepared for shipment to safran helicopter engines in Texas for further disassembly. Prior to shipment the module one (MO1, sn 18211) oil filter housing cap was removed to evaluate the condition of the oil filter. Upon removing the cap it was noted that the filter was not installed. Approximately one hundred and ten hours prior to the accident the aircraft engine was removed from the aircraft and modules one, two, and three were separated. Module one was sent to safran helicopter engines, the air carrier believed the MO1 was due overhaul based on total time accrued on the module. The air carrier determined that there had been a math error on the life limit/overhaul schedule of the MO1 committed by the previous maintenance facility.

When the air carrier realized the math error on the MO1 records and that it was not due overhaul they requested the MO1 be returned from safran helicopter engines. When safran helicopter engines repair station initially received the MO1THEY performed an incoming/receiving inspection. Their internal process requires removal of the MO1 oil filter during this incoming/receiving inspection. When the air carrier requested the return of the MO1 from safran helicopter engines they interrupted the repair station work flow. The MO1 had completed the incoming receiving inspection (oil filter removed) but had not started the inspection/overhaul scope of work.

The MO1 was returned to the air carrier with the oil filter housing cover installed. The historical service record for the MO1 had an entry made by safran helicopter engines that stated ?equipment returned repairable, not repaired, not airworthy as is?. The air carrier questioned this entry as there was no statement as to why it was unairworthy as it had been sent to safran helicopter engines as serviceable as removed with what was believed to be a few life limit hours remaining