1963 — Dec 8, Lightning strike, explosion, breakup, Pan Am Flight 214, Elkton, MD — 81

— 81 AirDisaster.Com. Accident Database. Accident Synopsis 12081963.
— 81 Aviation Safety Network. Accident Description. Pan Am Flight 214, 08 Dec 1963.
–73 passengers.
— 8 crew.
— 81 Civil Aeronautics Board. Aircraft Accident Report. Pan Am…Elkton, MD, Dec 8 1963.
— 81 Kimura. World Commercial Aircraft Accidents 3rd Ed., 1946-1993, V.1. 4-11-1994, p. 2-6.
— 81 Ludlum. The American Weather Book, 1982, p. 143.
— 81 NFPA. U.S. Unintentional Fire Death Rates by State. December 2008, p. 23.

Narrative Information

ASN: “After contacting Philadelphia Approach Control the crew elected to wait in a holding pattern along with 5 other aircraft because of extreme winds at Philadelphia. Flight 214 entered a holding pattern west of…New Castle. At 20:58 Clipper Tradewind suffered a lightning strike. This caused the initial ignition of flammable fuel vapors inside the left reserve fuel tank. This triggered explosions in the centre and right reserve fuel tanks as well. Fuel spilled and caught fire; the complete left wingtip separated as a result. The aircraft was then seen to crash in flames.” (Aviation Safety Network. Accident Description. Pan Am Flight 214, 08 Dec 1963.)

CAB: “A Pan American World Airways, Inc., Boeing 707-121, N709PA, Flight 214, crashed at 2059 e. s t., December 8, 1963, near Elkton, Maryland….

“Pan American Flight 214, a Boeing 707-121, N709PA, departed Friendship International Airport, Baltimore, Maryland, for Philadelphia, Pennsylvania, at 2024 1 December 8, 1963. The aircraft, with 73 passengers and a crew of eight…” (CAB, “Pan Am…Elkton, MD, Dec 8, 1963.”)

“…at 2058:56 the following transmission was heard on the Philadelphia Approach Control frequency 124 6 “MAYDAY-MAYDAY- MAYDAY” 5 Clipper 214 out of control. Here we go.” Seconds later another transmission on the same frequency was heard “Clipper 214 is going down in flames.” This latter transmission was made by the first officer of National Airlines Flight 16 (NAL 16). 6 NAL 16 was in the same holding pattern as Flight 214 but 1,000 feet higher, and the first officer had seen the Pan American flight descending on fire.

“ Immediately thereafter, the aircraft was observed to be on fire. A large portion of the left wing separated in flight and the aircraft crashed in flames approximately ten nautical miles southwest of the New Castle, Delaware VOR. All persons aboard, 73 passengers and eight crew members, perished in the crash and the aircraft was destroyed…..

“Nearly 600 pieces of wreckage were strewn outside the main impact crater in an area approximately four miles long and one mile wide….

“Lightning discharges can be hazardous to aircraft fuel systems by possibly igniting the fuel vapor within the tanks. Direct strokes may penetrate the wall of the tank or cause internal sparking, either from the high resistive and/or inductive voltages developed across internal discontinuities, or from possibly high voltages induced in the fuel probe wiring. In addition, flame can propagate through the vent system, from fuel vapors ignited at the vent outlet by direct strokes, streamering, or blast pressure waves, spark showers, and possible plasma penetration from direct strokes….

“To clarify the subject of lightning, a U. S Weather Bureau witness was called to testify at the hearing and various technical reports were reviewed. These sources indicate that a lightning stroke begins when the air’s resistance to the passage of electricity breaks down. At that time a faintly luminous stepped leader advances toward an area of opposite potential, the earth in the case of cloud to ground lightning. The difference in electrical potential between a cloud and the ground may be in the order of ten to one hundred million volts and discharge current may exceed 100,000 amperes with 10,000 amperes per micro-second 13 rate of current rise….

“The stepped leader advances toward the ground in a series of discrete branching movements, forming an ionized path down from the cloud. As a branch of the stepped leader is approaching the ground, the intensified electric field causes an upward moving streamer to form at a ground projection and advance toward the stepped leader. As the oppositely charged leaders meet, completing the ionized channel, an avalanche of electron flow follows, discharging the cloud to the ground. This entire sequence is accomplished in approximately one millisecond….

“Statistics indicate that the majority of lightning strikes to aircraft occur at ambient temperatures near the freezing level. This correlates with thunderstorm electrification theories that charge separation occurs about the freezing level. N709PA was at or near the freezing level just prior to the accident….

“The Board determines the probable cause of this accident was lightning induced ignition of the fuel/air mixture in the No. 1 reserve fuel tank with resultant explosive disintegration of the left outer wing and loss of control.” (CAB. Pan Am…Near Elkton, Maryland, December 8, 1963.)

CAB: “While in a holding pattern, the aircraft was struck by lightning, which induced fuel vapor ignition. This accident prompted the FAA to mandate static wicks be placed aboard all aircraft.”
(CAB. Pan Am…Elkton, MD, Mar 3, 1965.)

Rash: “…in what often is cited as the first positive lightning strike-induced accident involving a commercial aircraft, a Pan American World Airways Boeing 707-121 crashed on Dec. 8, 1963, while in a holding pattern awaiting clearance to land in Philadelphia after a flight from Baltimore. Accident investigators determined that the lightning strike had ignited fuel vapors. As a consequence of the ensuing investigation by the U.S. Federal Aviation Agency – a precursor of the Federal Aviation Administration (FAA) – devices known as lightning discharge wicks were ordered to be installed on all commercial jet airliners.” (Rash. “When Lightning Strikes,” Aero Safety World, June 2010, p. 21.

ASN: At the time this was the 4th worst aviation disaster in the U.S. (ASN, Pan Am 214, 8 Dec 1963)

Sources

AirDisaster.Com. Accident Database. “Accident Synopsis 12081963.” Accessed at: http://www.airdisaster.com/cgi-bin/view_details.cgi?date=12081963&reg=N709PA&airline=Pan+American+World+Airways

Aviation Safety Network. Accident Description. Pan American World Airways Flight 214. Flight Safety Foundation. Accessed 4-8-2020 at: https://aviation-safety.net/database/record.php?id=19631208-0

Civil Aeronautics Board. Aircraft Accident Report. Pan American World Airways, Inc. Boeing 707-121, N709PA Near Elkton, Maryland, December 8, 1963 (File No. 1-0015). 3 Mar 1965. At: http://dotlibrary1.specialcollection.net/scripts/ws.dll?file&fn=8&name=*P%3A%5CDOT%5Cairplane%20accidents%5Cwebsearch%5C120863.pdf

Kimura, Chris Y. World Commercial Aircraft Accidents 3rd Edition, 1946-1993, Volume 1: Jet and Turboprop Aircrafts. Livermore, CA: Lawrence Livermore National Laboratory, Risk Assessment and Nuclear Engineering Group. 4-11-1994.

Ludlum, David M. The American Weather Book. Boston: Houghton Mifflin Co., 1982.

National Fire Protection Association (John Hall, Jr.). U.S. Unintentional Fire Death Rates by State. Quincy, MA: NFPA, 31 pages, December 2008.