American Eurocopter CORP AS350B3 accident near Peach Springs, Arizona, May 18, 2014

The NTSB's narrative final · quoted from the NTSB record

The commercial pilot was repositioning the helicopter and advised ground personnel that he intended to land and perform a "fluid check." Company personnel reported that most pilots used this term when they intended to land away from the awaiting passengers and exit the helicopter to relieve themselves. The pilots would generally leave the engine running when outside the helicopter. The helicopter was equipped with an on board video recording system. The recording revealed that the pilot landed the helicopter in a location that had a direct buffeting crosswind. The pilot tightened the friction on the cyclic, which then did not move. The twist grip light illuminated, and engine audio was consistent with the throttle being moved toward ground idle. About 6 seconds later, the twist grip light extinguished, engine audio was consistent with an increase in power to flight idle; engine data parameters indicate that the twist grip was moved to flight idle. On the video, the collective position continued to increase. About 15 seconds later, the pilot exited the helicopter. External audio indicated a sound similar to N1 increasing. For the next 24 seconds, the video showed an increase in airframe buffeting. The helicopter then began to pitch nose down. One second later, the helicopter began to roll right; the roll increased, and the helicopter then began to yaw left. The sound of the door opening was heard, likely indicating that the pilot attempted to enter the helicopter. The helicopter continued to roll and yaw until noises consistent with the rotor blades impacting the ground were heard. The operator had a policy that required a pilot to always be at the controls of a running helicopter. However, according to pilot interviews, this policy was not generally followed, and the pilots would not shut down the helicopter when they needed to relieve themselves. However, pilots who were interviewed stated that they would leave the helicopter operating at ground idle. It could not be determined why the pilot would leave the helicopter while it was operating at flight idle without the flight controls properly secured.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.