The
National Transportation Safety Board (NTSB) officially declared that Kennedy's plane had crashed into the Atlantic Ocean off the coast of Martha's Vineyard. The probable cause of the crash was "the pilot's failure to maintain control of the airplane during a descent over water at night, which was a result of spatial disorientation". Under the heading "Spatial Disorientation", the report listed, from the FAA Instrument Flying Handbook Advisory Circular 61-27C, six examples: •
The leans •
Coriolis illusion •
Graveyard spiral •
Inversion illusion • Elevator illusion •
Autokinesis Kennedy was not qualified to fly his plane by "instruments only". The crash occurred in conditions not legally requiring such qualification.
Possible contributing factors Haze and visibility Atmospheric conditions along Kennedy's flight path on the night of the crash were occasionally hazy, which can lead to
spatial disorientation for pilots. Other pilots flying similar routes on the night of the crash reported no visual horizon due to
haze. Four months before the crash, Kennedy passed the FAA's written airplane instrument examination and later enrolled in an instrument rating course. He continued to receive flight instruction in New Jersey in his plane, including flights from CDW to MVY. His instructors said Kennedy required help working the
rudder pedals to taxi and land the plane because of his ankle injury.
Psychological stress The NTSB suggested that Kennedy's rocky marriage may have contributed to a source of stress by the time of the crash. Additionally, Kennedy's magazine,
George, was in serious financial trouble. According to the
Aeronautical Information Manual (AIM): "stress from everyday living can impair pilot performance, often in subtle ways. Distractions can so interfere with judgment that unwarranted risks are taken, such as flying into deteriorating weather conditions to keep on schedule."
Pilot distraction From 8:49 p.m., about ten minutes after departure, and for a five-minute period lasting until 8:54 p.m., Kennedy's plane flew in the same vicinity as
American Airlines Flight 1484, a
Fokker 100, which was on approach to
Westchester County Airport (HPN).
No flight plan or request for help Kennedy never received a weather briefing or filed a
flight plan with any
Flight Service Station. Except for the take-off portion of his flight, Kennedy did not contact any air traffic controllers; during the flight, he never requested help or declared an emergency. Under the conditions of his flight, Kennedy was not required to file a flight plan, and because he did not, no one knew his exact route or expected time of his arrival. According to the Weather Service International, as reported in the investigation by the NTSB, Kennedy made two weather requests before taking off. The information he was provided indicated that visibility ranged from along his route to at Martha's Vineyard.
Flight over featureless, open water Shortly after passing
Point Judith, Rhode Island, Kennedy's plane headed directly towards Martha's Vineyard. Instead of following the coastline of
Rhode Island Sound and
Buzzards Bay, which would have provided visible lights on the ground, Kennedy chose the shorter, direct path over a 30-mile (50 km) open stretch of water. According to the FAA Airplane Flying Handbook, crossing large bodies of water at night may be very hazardous, not only from the standpoint of ditching in the water but also because the featureless horizon visually blends with the water, in which case
depth perception and
orientation become difficult. During his interviews, Kennedy's orthopaedic surgeon stated that, at the time of the crash, he would have been able to apply the type of pressure that would normally be required to drive a car.
Incorrect radio frequencies While the NTSB examined the wreckage, they soon discovered that both of Kennedy's radios had incorrect frequencies selected. Kennedy had accidentally selected 127.25 for Martha Vineyard's
ATIS (automated weather information) instead of 126.25; likewise, he selected 135.25 for Essex County ATIS but it should have been 135.5. The NTSB declined to comment on the contribution this factor had in the crash, if any. ==Aftermath==