On October 15, 2004, a Hughes OH-6A (registration N6639R) operated by US Border Patrol was involved in an aviation accident near Jacumba, CA. Investigators recorded the probable cause as: the pilot's failure to maintain adequate clearance from the mountainous terrain, which resulted in the helicopter's tail rotor blades impacting rocks. A factor in the accident was the pilot's complacency. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A public-use law enforcement helicopter collided with rocks while performing low-altitude maneuvers at night. The pilot heard a bang and vibration, then landed. Tail rotor blades were found damaged, and paint transfers on a rock suggested the strike.
Incident Details
A public-use law enforcement helicopter sustained damage after colliding with rocks and terrain while conducting low-altitude maneuvers in mountainous terrain on a dark night. The pilot was performing a turning descent to provide the observer with a better view of the area. During the turn, he heard a loud bang followed by a vibration and subsequently opted to land.
Findings
After egressing the helicopter, the pilot discovered that approximately 3 inches of each tail rotor blade were missing. Days later, while inspecting the accident scene, he found red and white paint transfers on a rock located about 100 yards uphill from the landing site. The tail rotor blades were painted red and white, consistent with the paint transfers.
Pilot Statement
The pilot reported no mechanical malfunctions or failures with the helicopter prior to the impact. He stated that his complacency and eagerness to finish the flight might have contributed to misjudging the maneuver.