Air Transportation: Tilt Rotor Tragedies
January 26, 2024: The US Navy grounded its entire CMV-22B carrier logistics tiltrotor aircraft in December 2023 because one of them crashed off the Japanese coast. The navy returned its semi-retired C-2A fixed wing aircraft to perform the onboard deliveries to and from aircraft carriers. Earlier in 2023 there were problems with troublesome components in V-22 tilt-rotor aircraft. For example, V-22s were grounded because of a troublesome component, the Input Quill Assembly. This component is part of the propeller gear box, which also houses the aircraft clutch assembly that enables the V-22 to operate like a helicopter while landing and taking off and a fixed wing transport for the rest of the flight, traveling much faster than a helicopter.
Problems with V-22 reliability never seem to end. In mid-2022 the U.S. Air Force Special Operations Command grounded its 52 CV-22B transports indefinitely, except for emergencies. The air force wanted to discover what was the cause, and cure, for four incidents since 2017 involving HCE (hard clutch engagement) when the CV-22B switches the position of the rotors between vertical (helicopter) and horizontal (conventional flight) mode. There were also two fatal accidents this year involving Marine Corps V-22s. One accident was attributed to pilot error in unfamiliar mountain terrain. The other accident occurred on a desert training range. No reason given for that one. Marine V-22s have also suffered from HCE accidents but the marines do not consider these dangerous enough to ground its V-22s.
https://www.strategypage.com/htmw/htairmo/articles/20240126.aspx
