Pan Am Flight 115

Pan Am Flight 115 was a commercial flight from Paris via London to New York City. At 22:05 GMT (16:05 EDT) on 3 February 1959 it was involved in one of the most notable jet upset incidents of the jet airliner age, over the North Atlantic near Newfoundland.

Pan Am Flight 115

N712PA at Pan Am's Worldport (1961)
Incident
Date	February 3rd, 1959
Summary	Pilot error and poor crew resource management
Site	Over the North Atlantic Ocean near Newfoundland 52.5°N 40.5°W
Aircraft
Aircraft type	Boeing 707-123
Aircraft name	"Clipper Washington"
Operator	Pan Am
Registration	N712PA
Flight origin	Paris Orly Airport
Stopover	London Heathrow Airport
Destination	Idlewild International Airport
Occupants	129
Passengers	119
Crew	10
Fatalities	0
Survivors	129 (all)

Aircraft

The aircraft was a Boeing 707-121 with registration N712PA, nicknamed "Clipper Washington". Its first flight was on October 13th, 1958 (the same month that 707s entered regular service with Pan Am), and when the incident occurred less than four months later, the aircraft had accumulated only 705 total flight hours.[1]

Incident

The jet, crewed by pilot-in-command Captain Waldo Lynch, Captain Samuel Peters, flight engineer George Sinski, and navigator John Laird,[2] with 119 people on board, experienced an emergency descent of 29,000 feet from 35,000 feet with the autopilot engaged when the captain left the cockpit and entered the main cabin. During his absence, the autopilot disengaged and the aircraft smoothly and slowly entered a steep descending spiral. The copilot was not properly monitoring the aircraft's instruments or the progress of the flight and was unaware of the actions of the aircraft until considerable speed had been gained and altitude lost. During the rapid descent the copilot was unable to effect recovery. When the captain became aware of the unusual attitude of the aircraft he returned to the cockpit and with the aid of the other crew members was finally able to regain control of the aircraft at approximately 6,000 feet; they later made an emergency landing at Gander with damaged flaps.[3]

Investigation

Evidence was subsequently given to the then United States Civil Aeronautics Board that the aircraft was flying at 35,000 ft at Mach 0.82 and at a weight of about 195,000 lb. During the previous two flights the Bendix PB-20 autopilot was reported in one case to have caused a nose-down pitch and in another to have disconnected following a change of heading of 20 deg, but on February 3 operation was found to be normal on arrival at Gander. The disengagement warning light was fully dimmed.

Reports

Flight Magazine's issue of 3 April 1959 [4] reported "Captain Waldo Lynch, the pilot-in-command, said that the aircraft went into a sharp manoeuvre downward and to the right. At 17,000 ft the airspeed was over 400 kt, the electric trim button was inoperative, and his gyro horizon had tumbled. The copilot recounted that "At 2200Z the navigator posted a change in heading requiring left turn. Used autopilot turn knob. Turn O.K. . . . Then light buffeting, plus positive load factor building up. . . . Heavy buffeting caused panel lights to fail."

The flight engineer said that he was pinned to his seat as the Mach warning sounded. When the g load was relieved, he pulled the tailplane-power and autopilot circuit-breakers because he thought that the tailplane had "run away." Full nosedown tailplane inclination of 3 degrees was indicated. He wound it back to the nose-up position but later trimmed nose-down.

Aviation Safety Network reports [5] the cause of the incident as unintentional disconnection of autopilot while captain had left the cockpit and entered the passenger cabin. The copilot did not pay sufficient attention to the instruments and the plane went into a dive in a clockwise spiraling turn.

Later history of the aircraft

After being operated by a number of firms, the airframe was finally scrapped in August 1984, at Taipei, Taiwan.[6]

References and notes

1. "Aviation Safety Network". ASN Wikibase Occurrence # 138612. Retrieved 23 January 2012.
2. Pollock, Steven (2014). Deadly Turbulence: The Air Safety Lessons of Braniff Flight 250 and Other Arlines, 1959-1966. Jefferson, NC: McFarland & Company, Inc., Publishers. p. 11. ISBN 978-0-7864-7433-2. Archived from the original on 2018-12-20.
3. "Aircraft Accident Report" (PDF). Civil Aeronautics Board. November 3, 1959. Retrieved September 19, 2018. This article incorporates text from this source, which is in the public domain.
4. "Air Commerce". Flight. Retrieved 23 January 2012.
5. "Aviation Safety Network". ASN Wikibase Occurrence # 138612. Retrieved 23 January 2012.
6. "Databases". Pan Am logbook magazine. Archived from the original on 2015-07-29. Retrieved 23 January 2012.

External links

• Aircraft Accident report Civil Aeronautics Board