Accident Overview
A helicopter contracted by NBC to conduct daily highway traffic observations in the New York City area crashed into the Hudson River. The aircraft, carrying a pilot and a passenger who was an NBC radio traffic reporter, was flying north along Manhattan's West Side at an altitude of approximately 75 feet.
Witness Observations
Witnesses reported seeing the helicopter's main rotor blades stop rotating. The aircraft then descended rapidly, struck the top of a chain link fence at a river pier, and crashed into the Hudson River, sinking in 15 to 20 feet of water.
Investigation Findings
Post-accident examination of the helicopter revealed that the sprag clutch was inadequately lubricated. The clutch had 'rolled over' in the opposite direction of its intended design, resulting in damage to the sprag assembly. Several sprags and both activating springs were broken, and sprags of different sizes had been installed. Furthermore, an unauthorized, overhauled clutch had been installed in the aircraft.