Flight Crew Last 90 Days 180; Flight Crew Total 14000; Flight Crew Type 3500
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Declared Emergency
Aircraft
At FL400; all lights on MCP flashed and autopilot and autothrottle kicked off. Aircraft dipped and rolled right. MCP completely failed and autopilot and autothrottle continued to cycle on and off. Every time they cycled; aircraft would roll and pitch to grab whatever MCP thought was in it. Declared an emergency; diverted to ZZZ with no pitch trim. Rest of flight uneventful besides having to muscle aircraft a bit.
With a total loss of the MCP (Mode Control Panel) and ALL of its associated functions; and it intermittently coming back on then off again. Even with autothrottle and autopilot switches OFF; the system would grab control of the aircraft and attempt to trim; turn; descend; or climb to whatever status it defaulted to when powered up! Had to wrestle with the aircraft the entire descent and landed with pitch and roll excursions.
B757 flight crew experiences an MCP failure at FL400 resulting in erratic autopilot and autothrust operation and failure of the horizontal stabilizer trim. Flight diverts to the nearest suitable airport.