Page:CAB Accident Report, Pan Am Flight 115.pdf/2

- 2 - Flight 115 departed London at 1815 with 119 passengers. The flight plan called for an IFR flight to Gander of 4 hours and 58 minutes at maximum cruise thrust. The aircraft was to cruise at an altitude of 28,500 feet to the South Shannon intersection, 29,000 feet to 20 degrees west longitude, and 31,000 feet to Gander. A routine operation was conducted until near 30 degrees west longitude where a frontal condition accompanied by heavy thunderstorms was encountered. Because the flight, flying at its assigned altitude, was passing through the tops of these storms in moderate turbulence and encountering light icing, clearance was obtained from Shannon and Gander OAC (Oceanic Area Control) to climb to and cruise at 35,000 feet. At this altitude the aircraft was on top with all stars visible.

At approximately 2150, Captain lynch went to the main cabin. Captain Peters remained in the cockpit, seated in the copilot's seat. The aircraft was in maximum cruise configuration flying at Mach 0.82 in smooth air; autopilot was engaged in the manual mode and the altitude hold was on; gross weight was between 190,000 pounds and 195,000 pounds; and outside air temperature was minus 55 degrees centigrade. The aircraft position was 52.5 degrees north latitude 40.5 degrees west longitude.

All other crew members were at their stations and Mr. Mackey, a company dispatcher from Idlewild on an indoctrination trip, was seated in the observer's seat, immediately behind the captain in command. Captain Peters said his belt was sung and the seat was so adjusted that he had easy access to the controls.

At approximately 2200 the navigator posted a change in heading requiring a left turn of about 20 degrees. Captain Peters complied, using the turn knob of the autopilot in so doing. He said that he observed the new heading on his RMI (radio magnetic indicator) for several seconds and that the autopilot was holding the heading in a normal manner. He then began to work on the "How Goes It“ curve attached to a clipboard resting on his lap, which necessitated computations being made as to time, distance, cruising speed, and fuel consumption, some parts of which are computed by the navigator. During this time his headset was positioned on both ears as he was waiting to copy the 2205 Gander weather broadcast, and he said he did not observe the forward instrument panel during this time.

The first indication he had that the flight was not proceeding normally was when he felt the aircraft buffet. This was immediately followed by a feeling that positive acceleration forces were building up rapidly. The buffeting increased in intensity and his instrument panel lights went out. Quickly he looked at the captain‘s instrument panel which remained lighted and saw that the captain's artificial horizon had tumbled and consequently was of no use to him. He then glanced up and saw the stars moving rapidly counterclockwise, indicating that the aircraft was in a nosedown right spiral about to roll over on its back. At this point he grabbed the control wheel, pushed the autopilot release button, and attempted to stop the roll by applying left aileron and rudder, but by this time he was virtually imobilised physically by the pressures created during the maneuver. Various system-warning and fire-warning lights were being activated intermittently and the Mach warning bell was heard.