Amateur-built Air Cam N125AC accident near Everett, Washington

Probable cause

The pilot's inadvertent encounter with the rotor downwash from a hovering heavy-lift helicopter.

NTSB analysis

The pilot taxied the ultralight airplane west between two rows of hangars up to the boundary of the non-movement area before stopping to contact ground control. At this time an Army Chinook helicopter made an approach to runway 34R before entering a hover over the runway in front of the pilot at an altitude estimated to be from 75 to 100 feet above ground level. As the helicopter descended to about 20 to 30 feet above ground level, the rotor wash from the helicopter picked the airplane up off the ground and blew it backwards and to the right. The airplane subsequently dropped to the ground on its right wingtip, coming to rest upright about 25 to 30 feet from where it was originally positioned. The airplane sustained damage to its right wing, including the flap and aileron, and the right main landing gear.

Text from the NTSB. Open the NTSB docket for WPR10CA132 for the full record.