Eastern Airline's Flight 401 from New York to Miami was about to touch down, when their landing gear malfunctioned. The crew promptly engaged autopilot and climbed back to 2000 feet to try and fix the problem. Eventually, after failing to fix the gear immediately, they had to send someone down underneath the plane to manually check. Unbeknownst to the crew, the autopilot had been disengaged, and the plane was slowly losing altitude. The descent was so gradual that no one had noticed, until it was too late.