The pilot reported that, while hovering the helicopter to park between three stationary helicopters at the airport in Van Nuys, California, the ground crew gave him the signal for a 180° “pedal turn.”
As the helicopter was about to touch down, he felt a shudder in the airframe. He then immediately rolled the throttle closed and completed an emergency shutdown.
Post-accident examination revealed that the tail rotor blades struck the main blades of a stationary helicopter, which likely caused the shudder felt by the pilot.
The helicopter sustained substantial damage to the tail rotor and main rotor systems.
The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
Probable cause: The pilot’s failure to maintain clearance from a stationary helicopter during landing. Contributing to the accident was the ground crew’s failure to ensure that the helicopter would clear the stationary helicopter.
NTSB Identification: GAA18CA107
This January 2018 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
“..tail rotor struck the stationary helicopter main blades… likely caused the shudder felt by the pilot.” Do you reckon??
Cause …. failure (by everybody!) to assure clearance. Hmmm. A remarkable conclusion.
This probably would have worked out better if the helicopter had stayed high enough to not have to be concerned about contacting any other aircraft until its maneuvering was complete and clearances were more easily judged as it descended to the ground. Helicopters work out better on the airport if they have wheeled landing gear and do not have to fly everywhere they go also. I guess it is for the utilitarian aspect of their missions that they use skids for gear but that is not the best arrangement on a airport.
Most helicopters hover about 2-3 ft above the ground so that in the event of an engine failure there will be enough rotor inertia to cushion the landing. In retrospect, with a confined parking area the prudent thing to do is land in a clear area, shut down and move the aircraft with the ground handling wheels. Same goes for departure…