Schweizer 269D N411HU accident near Stewartstown, Pennsylvania

Probable cause

The pilot's inability to maintain yaw control while transitioning to an out of ground effect hover due to a loss of tail rotor effectiveness.

NTSB analysis

The pilot reported that he made an uneventful approach into the 8-to-10 knot wind nearly directly down the runway. While operating the helicopter out of ground effect about 15 to 20 ft above ground level and about 10 to 20 knots, he began to apply left antitorque pedal to start to hover. With wind from the right, the helicopter then started turning clockwise; he applied left antitorque pedal, which did not stop the rotation, and the helicopter completed about 12 turns before impacting the ground. The passenger recalled the helicopter spinning clockwise and coming to rest on its left side. The helicopter sustained substantial damage to the fuselage, horizontal stabilizer, and rotor blades. The pilot did not recall reducing throttle or lowering collective during the accident sequence. Postaccident examination of the tail rotor flight control and drive system revealed no evidence of preimpact failures or malfunctions that would have precluded normal operation. Although the tail rotor control cable tension was about 2 lbs, or about 3%, less than the helicopter manufacturer’s specifications, that discrepancy would not affect operation of the tail rotor. Given this information, it is likely that the pilot was unable to stop the yaw and lost control of the helicopter due to a loss of tail rotor effectiveness.

Text from the NTSB. Open the NTSB docket for ERA18LA192 for the full record.