On April 11, 1995, a Hiller UH-12E (registration N508HV) was involved in an aviation accident near Timber, OR. Investigators recorded the probable cause as: The pilot's failure to notice the shipping block during preflight, which restricted the flight control system and led to loss of control. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter crashed shortly after takeoff because a shipping block left in the rotor head restricted flight controls. The pilot had not removed the block during preflight.
Accident Overview
A helicopter was transported on a trailer to a location intended for aerial application work. After arrival, the main rotor blades were attached to the rotor head, but a shipping block that had been used during transport was not removed.
Preflight Actions
During the preflight inspection, the pilot did not notice that the shipping block remained in place. The block was still installed when the pilot began the takeoff procedure.
Loss of Control
As the helicopter lifted off from the trailer, the shipping block interfered with the flight control system, preventing the pilot from maintaining control. The helicopter entered an uncontrolled descent and impacted the terrain.
Probable cause
The pilot's failure to notice the shipping block during preflight, which restricted the flight control system and led to loss of control.