All 46 of the US Marine Corps’ Bell Boeing MV-22 Osprey tiltrotor vertical/short takeoff and landing aircraft have been temporarily grounded after an cold-weather check identified a computer chip redundancy fault in the flight control systems.

Each Osprey is triple redundant, but extreme weather trials on the aircraft, the USMC found computer chips that provide back-up on the flight control system could fail to perform as required in this specific role.  "Built-in test procedures in the flight control computer (FCC) that are performed before flight detected the failure; this failure mode has not occurred in flight," the Corps says.

"Engineering analysis of the issue is continuing and FCCs are being removed and inspected to isolate the fault-producing chip," the Marines add. FCCs with the fault-producing chip will be fixed, and unaffected FCCs will be returned to aircraft, allowing all aircraft to return to flight, the Corps says in a statement.

Source: Flight Daily News