American Flyers Airline Flight 280/D

The aircraft was a Lockheed L-188 Electra four-engined turboprop airline registered as N183H.^[4] It had first flown in January 1961 and was bought by American Flyers Airline in January 1963.^[5] It is the same plane that carried the Beatles from city to city in 1964 during their second tour of the U.S.^[6]

The U.S. Civil Aeronautics Board (CAB) investigated the accident.^{[1]: 1 [7]}

Investigators found no evidence of mechanical failure or defect related to the accident, although the flight data recorder had suffered a mechanical failure unrelated to the accident and may not have been properly checked by the flight engineer before the flight; it had produced no recording for the flight.^[8] The airplane did not have (and was not required to have) a cockpit voice recorder.^[1]

Some days after the crash, it was learned that the pilot, Reed Pigman, who also happened to be the president of American Flyers, was under care for arteriosclerosis.^[9] An autopsy of Pigman determined his cause of death to either be multiple injuries or coronary artery sclerosis.^[10]

It was also determined that Reed Pigman had falsified his application for a first-class medical certificate. He had not disclosed that he was diabetic or that he had a history of heart issues dating back almost two decades; either of these would have been disqualifying factors for the certificate.^[11]

On March 28, 1967, the CAB published its final report. The CAB determined that the probable cause for the accident was:

[T]he incapacitation, due to a coronary insufficiency, of the pilot-in-command at a critical point during visual, circling approach being conducted under instrument flight conditions.^[1]: 1

• List of unrecovered and unusable flight recorders