This much is known about Kennedy’s last flight:

Kennedy, Carolyn Bessette Kennedy and her sister Lauren Bessette arrived at Essex County Airport near Fairfield, N.J., where Kennedy kept his single-engine Piper Saratoga II plane, at dusk on Friday.

Kyle Bailey, the New Jersey pilot who is believed to be the last person who saw the trio, was also planning a flight to Martha’s Vineyard, but he canceled his plans because of poor visibility. “The weather was very marginal, four to five miles visibility, extremely hazy,” Bailey told the Washington Post. “Over open water, you have reduced visibility anyway. With the haze, in the dark, you lose sight of the horizon. You don’t have landmarks.”

After loading their baggage and taxiing, the Kennedys’ plane departed at 8:38 p.m. from runway 22. The plane made a 180-degree turn toward the northeast. According to radar data, the plane then climbed to 5,600 feet and continued easterly along the coast until it came to Westerly, R.I., at 9:26 p.m. After passing Westerly, Kennedy’s plane began its descent toward Martha’s Vineyard.

At 9:40, the plane was about 17 miles from the airport at Martha’s Vineyard, and had descended to 2,200 feet, maintaining that altitude for 20 seconds. The last blip on the radar screens at Provincetown, Mass., and Cape Cod approach controls, where the plane was tracked, came 14 seconds later, at an altitude of 1,100 feet. In just 14 seconds, the plane dropped 1,100 feet, compared to the 400-500 feet per minute norm at that stage of landing. Then complete radar silence. No signs of distress. Eerie silence.

Training and experience: “A pilot with less than 200 hours is considered
low-time.”

There are conflicting reports about just how much time Kennedy had logged
in the cockpit. The Boston Globe reported Sunday that he had only
registered 46 flight hours, quoting an unnamed FAA source, only six hours
beyond the 40 required for a license. But other publications have credited
Kennedy with roughly 100 hours of flying time — which would still mark him
as a novice.

While flying experts were reluctant to directly criticize Kennedy’s
decision to fly that night, there was near-consensus that his novice status
made such a flight a challenge. “Reasonable pilot judgment says that, if
I’m a relatively new pilot and I don’t have a lot of night experience, and
if it’s hazy and the visibility is not very good, then I would say, ‘This
may be beyond my skill level,’” Warren Morningstar, spokesman for the
Aircraft Owners and Pilot’s Association (AOPA), the world’s largest civil
aviation organization, told Salon News.

“A pilot with less than 200 hours of logged time is considered low-time and
there’s a corresponding decrease in the number of accidents after pilots
reach that level,” Morningstar said.

Although Kennedy was technically certified to fly in the conditions he
encountered Friday night, he did not have special training to read flight
instruments, which could have helped him navigate at night over water. The
instrument-rated license is often dubbed the “blind flying license,” with
good reason.

In a 1993 Atlantic Monthly article headlined “The Turn,” William Langewiesche
explained the total disorientation that comes with night flying: “The
inner ear, and with it the sense of balance, is neutralized by the motion
of flight. The airplane could be momentarily upside down and passengers
would not know.”

To obtain a pilot’s license, students must spend three hours flying in
darkness, and have three hours of instrument training. But instrument
flying “gives the pilot an extra set of eyes that virtually doubles his or
her vision, safety and utility,” according to a course description for an
instrument training course at American Flyers Flight School.

Without instrument training, pilots say it would be href="/news/feature/1999/07/20/pilot/index.html">easy to get
disoriented in weather conditions like those that surrounded Martha’s
Vineyard Friday night — flying in haze, at night, over water.

Conditions: “You couldn’t see Martha’s Vineyard.”

According to the AOPA, weather-related accidents account for almost 30 percent of all fatal, pilot-related accidents in single-engine airplanes like Kennedy’s, and darkness significantly increases the likelihood of bad-weather mishaps.

Air traffic controllers and witnesses said there was haze surrounding Martha’s Vineyard Friday night that diminished Kennedy’s visibility. Dr. Bob Arnot, chief medical correspondent for NBC and an experienced pilot, also was flying in the area Friday night. He said visibility was limited by haze as he passed about three miles south of the Vineyard just after 9 p.m. He had to rely on instruments to land at the nearby island of Nantucket, where he vacations.

“It was just black,” Arnot said. “You couldn’t see Martha’s Vineyard.”

Several pilots said they canceled flights that night. “I was planning on going to Martha’s Vineyard last night, too,” said Kyle Bailey, the pilot who saw Kennedy just before he took off. “But it was so hazy. I’m very cautious, though. And I’m not crazy about flying over water at night.”

Joe Orlando, a pilot who also flies out of the Essex County Airport, told the Hackensack Record he decided not to fly that night either. “Visibility was at least three miles Friday night. But I don’t go unless it’s five,” said Orlando, who called Kennedy’s New Piper “the sports utility vehicle of the air.”

After studying Friday night’s radar reports, investigators at the National Transportation Safety Board now believe that Kennedy’s plane went into what is known as a graveyard spiral, the most lethal of airplane spins. In a graveyard spiral, a plane locks into a tight turn, accelerating rapidly, with the nose of the plane pointed straight down.

Though it is possible to recover from the spin, without the perspective of a horizon, a pilot may not even know he or she is in a graveyard spiral until it is too late. The spin can exert such pressure on the plane it can break up in midair.

In a recent study commissioned by the University of Illinois, 20 students flew into simulated “instrument weather” — weather so bad that pilots are forced to rely on dials and meter readings to navigate. All 20 ended up in fatal spins. The average amount of time it took before their simulated crash was 178 seconds, or just under three minutes.

“Flying at night in those conditions was probably not the best judgment,” flight instructor Jeff Broomall told the Canadian National Post.

The injury: “With his broken foot, he had trouble with the pedals.”

Kennedy broke his foot paragliding into a tree last month, and the break kept him from flying solo all summer long — until Friday night. Kyle Bailey, the New Jersey pilot who was the last to see Kennedy alive, noticed him limping as he got ready to make the flight Friday night.

“He had at least one crutch. I saw him limping,” Bailey has told news outlets. “I told my family, ‘I can’t believe he’s going up in this weather.’” Questions about the condition of Kennedy’s foot have loomed large, because his Piper Saratoga had foot pedals. Just last Monday, Kennedy visited Toronto businessman Keith Stein, to discuss a possible investment in George magazine, and he was still in a cast and on crutches.

“He flew with a co-pilot on this occasion because … he told me that with his broken foot, he had trouble with the pedals,” Stein told Reuters. According to some accounts Kennedy got the cast off on Thursday, and was cleared by doctors to fly.

“He had a hard cast and was using crutches,” recalls another businessman who also met last month with Kennedy in New York to discuss a partnership with George magazine. “He was pretty pathetic on those crutches. I’m so sorry he made such a bad judgment call. I can’t believe a novice pilot would head out into the night and haze over the water without an instrument rating.”

A recently broken foot could have restricted Kennedy’s range of motion, but no orthopedists would comment on that possibility without having examined him. Dr. Alan Gross, an orthopedic surgeon from Toronto known for his treatment of professional athletic injuries, told Salon News: “I can’t possibly comment on this fracture without actually examining it. It’s too contentious. You’re going into choppy waters here.”

Some pilots dismiss the notion that a weakened foot would interfere with Kennedy’s flight performance, saying the foot pedals, or rudders, are rarely used, and don’t require much pressure anyway. But Valerie Flanagan, a spokeswoman for New Piper Aircraft, told Salon News, “With the airplane, of course, you need two feet to maneuver. How his [injury] interfered, I can’t say.”

Family pressures: “My wife insists.”

Flying at night wasn’t Kennedy’s first choice. The Kennedy trip was scheduled for daylight hours, but had to be postponed when sister-in-law Lauren Bessette, a vice president at Morgan Stanley Dean Witter, got held up at work and couldn’t leave early as planned. The party then hit traffic on the way to the airport, further delaying the trip and pushing it back until after dark. There has been speculation that the delay also caused Kennedy to take shortcuts as he ran through pre-flight checks, warming up the plane in a practice area, for instance, rather than on the runway.

On Monday, the New York Post reported that Kennedy had been reluctant to fly into Martha’s Vineyard in the first place, but had been pressured to do so by his wife, Carolyn. Kennedy reportedly told C. David Heymann, the author of “A Woman Called Jackie,” whom he was recruiting to write for George, that “I don’t even want to go to Martha’s Vineyard. I’m flying my own plane … Unfortunately, I have to take my sister-in-law with us. She’s going to Martha’s Vineyard. My wife insists I take her there.

“I don’t want to do that,” Kennedy reportedly told Heymann. “I said I’d rather fly straight to Hyannis … but my wife’s insisting.” Heymann told the Post that the complaints about his wife sounded “tongue-in-cheek … as though, ‘What can you do with a wife who has a bulldog tenacity.’”

Kennedy’s last words to Heymann were: “This means I have to land twice. I’m really not that experienced a pilot.” Heymann did not return calls to Salon News.