The NTSB has issued its findings on the accident, in July last year, which took the lives of John F Kennedy Jr, his wife Carolyn and her sister Lauren.

The NTSB has issued its findings on the accident, in July last year, which took the lives of John F Kennedy Jr, his wife Carolyn and her sister Lauren. His aircraft was a six seat Piper Saratoga, a PA 32R 301.

Kennedy, a non instrument rated pilot, obtained weather forecasts for a cross country flight, which indicated VFR conditions with clear skies and visibilities that varied between 4 to 10 miles along his intended route. He then departed, on a dark night.According to radar data, the plane proceeded over land at 5,500 feet. About 34 miles west of Martha’s Vineyard Airport, while crossing a thirty mile stretch of water to its destination, it began a descent that varied between 400 to 800 fpm. About seven miles from the shore, the plane began a right turn. The plane stopped its descent at 2,200 feet, then climbed back to 2,600 feet and entered a left turn.While in the left turn, the plane began another descent that reached about 900 fpm. While still in the descent, it entered a right turn. During this turn, the rate of descent and airspeed increased and eventually exceeded 4,700 fpm. It struck the water in a nose down attitude.Airports along the coast reported visibilities between five and eight miles. Other pilots flying similar routes that night reported no visual horizon while flying over the water because of haze.The pilot’s estimated total flight experience was about 310 hours, of which 55 hours were at night. His estimated flight time in the accident plane was about 36 hours, of which about 9.4 hours were at night. About three hours of that time was without an instructor on board, and about 0.8 hours of that was flown at night and included a night landing.In the fifteen months before the accident, the pilot had flown either to or from the destination area about 35 times. The pilot flew at least seventeen of these flight legs without an instructor, including five at night. Within 100 days before the accident, the pilot had completed about fifty per cent of a formal instrument training course.An FAA Advisory Circular (61 27C) Instrument Flying: Coping with Illusions in Flight, states that illusions or false impressions occur when information provided by sensory organs is misinterpreted or inadequate and that many illusions in flight could be caused by complex motions and certain visual scenes encountered under adverse weather conditions and at night. The AC also states that some illusions might lead to spatial disorientation or the inability to determine accurately the attitude or motion of the aircraft in relation to the earth’s surface. The AC further states that spatial disorientation, as a result of continued VFR flight into adverse weather conditions, is regularly near the top of the cause/factor list in annual statistics on fatal aircraft accidents.

According to AC 60 4A, Pilot’s Spatial Disorientation, tests conducted with qualified instrument pilots indicated that it can take as long as 35 seconds to establish full control by instruments after a loss of visual reference of the earth’s surface.AC 60 4A also states that surface references and the natural horizon may become obscured even though visibility may be above VFR minimums and that an inability to perceive the natural horizon or surface references is common during flights over water, at night, in sparsely populated areas, and in low-visibility conditions.Examination of the airframe, systems, avionics, and engine did not reveal any evidence of a pre impact mechanical malfunction. The probable cause was the pilot’s failure to maintain control of the plane during a descent over water at night, which was a result of spatial disorientation. Factors in the accident were haze, and the dark night.