China Northern Airlines Flight 6901
When activated, however, the autopilot went into vertical speed mode with a setting of -800 feet per minute.The crew's failure to disconnect the autopilot and manually land the airplane contributed to the accident.When the Ground Proximity Warning System (GPWS) issued an aural alarm, the captain asked his first officer what the words "Pull up" meant.Consequently, the pilots ignored the warnings and failed to correct their excessive rate of descent, causing the plane to strike power lines and a wall before coming down in a field.[1][2] The aircraft involved was a McDonnell Douglas MD-82 with the registration B-2141 and manufacturer's serial number 49849.