Enstrom F-28C N631DP accident near Bloomsburg, Pennsylvania

Probable cause

The relieved pilot’s failure to maintain clearance from the rotating main rotor blades after he exited the helicopter.

NTSB analysis

The pilot/owner had just taken control of the helicopter from another pilot. As the relieved pilot was walking away from the helicopter and between the 10- and 11-o'clock position forward of the helicopter, he came into contact with a rotating main rotor blade. The pilot/owner stated that, when exiting the helicopter, it was the company's practice to disengage the rotor drive system and secure the collective control. In this condition, the rotor blades droop below the normal height, and the drooping is most pronounced in the 9- to 12-o'clock position of the rotor disk. According to the helicopter manufacturer representative, the main rotor height can vary depending on how the helicopter landing gear was serviced. In addition, depending on the position of the cyclic, the main rotor can descend lower than 6 feet when the main rotor is operating. It is likely that the pilot/owner unintentionally moved the cyclic, which resulted in the rotor blade descending, and, in combination with the rotor droop, the main rotor blade would have been low enough to strike the relieved pilot's head.

Text from the NTSB. Open the NTSB docket for ERA13LA433 for the full record.