Power turbine pinion gear from the accident helicopter, left, and an exemplar power turbine pinion
gear.
Parts of a Bell 407’s engine were so “significantly worn and smeared” that the engine could no longer power the helicopter’s rotor system, causing the pilot to lose control and the helicopter to crash into the Gulf of Mexico, the U.S. National Transportation Safety Board (NTSB) says.
The pilot and his passenger were killed in the Dec. 7, 2019, crash, about 25 nm (46 km) off the Louisiana coast, and the helicopter was destroyed.
In its final report on the accident, the NTSB said the probable cause was the “total loss of engine power due to the failure of the engine’s Nos. 3 and 4 bearings and the power turbine pinion gear, and subsequent loss of main rotor rpm, which resulted in a loss of control and impact with the water.”
The accident occurred as the helicopter, operated under U.S. Federal Aviation Regulations Part 135 as a business flig…
