On November 3, 1973, Pan Am flight 160 departed
John F. Kennedy International Airport in New York for the destination of
Frankfurt with a stop in Prestwick, Scotland. The flight departed at 08:25 EST and was carrying of chemicals. The first sign of trouble occurred at 09:04 EST with smoke in the lower 41 electrical compartment and this was reported to control. They also mentioned that they were going to divert to Boston. The crew contacted
air traffic control (ATC) and was granted a return to JFK. Then, a major setback occurred, which was that the cockpit became thick with smoke. This made them turn back around to Boston. To help get the plane under its maximum landing weight (MLW), the crew descended to to increase the fuel burn rate. The crew requested to land on Runway 33 Left and this was approved by ATC. About this time, the crew shut off all non-essential systems. Soon, the transponder became inoperative. Once they were on final approach, with the airplane properly configured with flaps, the yaw damper was disengaged as a fatal result of critical mistakes during the execution of procedures. Henceforth, this made control of the plane hard at low speeds. Witnesses saw smoke pouring out of the cockpit windows, and the aircraft stalled out and crashed in a near vertical position with nose facing down. == Cause ==