As fresh ships and sensors gathered offshore to probe for wreckage, investigators released new data today that portrayed the final half-minute of John F. Kennedy Jr.'s doomed flight as an uncontrolled plunge into the sea.
Fresh radar tracks made available to the investigative team showed the Piper Saratoga plummeting from 2,200 feet to 1,100 feet in a span of 14 seconds Friday night, a rate far beyond the aircraft's safe maximum. The last known radar snapshot, at 34 seconds past 9:40 p.m., caught the plane at about twice the height of the Washington Monument and losing altitude at an average rate of 4,700 feet per minute.
By then, experienced pilots said, there was little or no chance that Kennedy could save himself, his wife Carolyn Bessette Kennedy, 33, and her sister Lauren Bessette, 34.
Massachusetts State Police divers made their first foray to the Atlantic seabed just after noon today, but found neither bodies nor wreckage. They pulled away from the Menemsha Coast Guard dock in three low-slung boats at a few minutes after noon, parting with a military chaplain who counseled them, and returned about three hours later. They had time to search only the first of 10 potential wreckage sites, and Coast Guard Capt. Russell Webster said the suspect sonar image turned out to be a boulder of 14 by 4 by 2 feet.
Without yet the comfort of definitive proof, the Kennedy and Bessette families today issued statements of mourning that accepted the government's judgment that there is no further hope of finding the travelers alive.
"We are filled with unspeakable grief and sadness by the loss of John and Carolyn and Lauren Bessette," Sen. Edward M. Kennedy (D-Mass.) said on behalf of his family. "John was a shining light in all our lives and in the lives of the nation and the world that first came to know him as little boy."
A joint statement by William J. Bessette, his former wife Ann Freeman and her husband Richard Freeman joined the Kennedys in thanking the rescue teams who made the "exhaustive search" for their daughters. "Each of these three young people -- Lauren Bessette, Carolyn Bessette Kennedy and John F. Kennedy Jr. -- was the embodiment of love, accomplishment and passion for life," they said in a statement read by family friend Grant Stinchfield. They said "John and Carolyn were true soul mates" and took "solace in the thought that together they will comfort Lauren for eternity."
Blake Gilmore, one of the state police divers, said today that his team would "put more divers down until we feel comfortable the area has been covered and we've secured it and we know that it has been eliminated" as a possible wreckage site. A Navy salvage vessel, the USS Grasp, also arrived off Martha's Vineyard today with divers and equipment rated for greater depth and longer endurance underwater.
The Grasp's entry into the underwater search was accompanied by substantial new search assets elsewhere. The Coast Guard cutter Willow, which has been here from the start, set off from Woods Hole at 3:20 this afternoon with new side-looking sonars aboard, and the Whiting, a sister ship of the National Oceanic and Atmospheric Administration's research vessel, the Rude, also steamed into the 24-square-mile search grid.
Further east on Cape Cod, in Hyannis, a steady flow of pilgrims made their way to various Kennedy-related sites. Among them were newlyweds Bill and Tracey Laskey of Claremont, N.H., on the first day of their long-planned honeymoon. On impulse they stopped at the John F. Kennedy Memorial, a quiet sweep of lawn and fountain overlooking the harbor, and placed their bridal bouquet of pink and purple carnations.
"It's just a loss to everyone," said Bill Laskey, groping to explain their condolence call. "It shouldn't have happened. Coming to a wedding! An awful thing."
Robert Pearce, who is leading the investigation of the National Transportation Safety Board, said the new flight data came from a radar that picked up the Kennedy plane substantially lower than the last reading previously made available to the panel. The new data gave a "different picture" of what still looked early today like a controlled, if rather rapid, descent. Often, preliminary information is refined and changes during the course of an investigation.
Pearce carefully avoided any analysis of the rapid descent, but experts said some implications are already clear. A jet aircraft can descend as rapidly as 5,000 feet a minute or more in emergencies, but propeller aircraft are considered incapable of that rate.
"Forty-seven hundred feet in a propeller airplane would generally be regarded as a dive, not a descent," said Drew Steketee, senior vice president of communications for the Aircraft Owners and Pilots Association.
Pearce said the radar recorded the plane at 2,200 feet at 9:40 p.m. and 20 seconds. Four seconds later it was at 1,900 feet, five seconds later at 1,600 feet and five seconds later at 1,100 feet.
The data, combined with the fact that Kennedy made no distress call, indicates that the cause of the crash probably developed rapidly.
Pilots said there are a number of ways that an aircraft could fall into such a dive, especially on a moonless night over the ocean with no visual cues of what is up or down.
For instance, a disoriented or incapacitated pilot can allow a plane to go into a "graveyard spiral." Going faster than the plane's "never exceed" speed of about 220 miles per hour can cause pieces of the plane to rip off. Going slower than the stall speed of about 75 mph would cause the plane to descend, but some pilots expressed doubt a stall would produce a 4,700-foot-per-minute descent so quickly.
Numerous mechanical problems could have caused the crash. But a mechanical explanation was made less probable by the results of the plane's last annual inspection, which Pearce said took place on June 28, just 18 days before the flight. Most structural or mechanical failures normally would be discovered during such a check.
Pearce said Kennedy's maintenance records apparently went down on the plane with him. However, he said maintenance invoices show one other procedure -- an adjustment of the plane's magnetic compass on July 13.
The plane also had enough fuel. Pearce said records at the Caldwell airport in New Jersey show that it received 62 gallons on July 11, and other records do not indicate any other flights before the fatal trip. It would have burned far less than 62 gallons in the 62 minutes it was airborne toward Martha's Vineyard.
Pearce also said the safety board is looking into reports by the plane's previous owner that he had installed a small voice recording device that could record the last few minutes of radio or cockpit intercom transmissions.
Speaking of the survivors, President Clinton said today: "They are very strong people, and I think they're carrying on as well as any human beings could, but they need the support and prayers of our country."
That, it appeared, they had. Makeshift shrines continued to flower at the Kennedy Library in Boston, at the TriBeCa apartment where John F. Kennedy Jr. and his wife lived, at the museum in downtown Hyannis.
At the memorial where the Laskey newlyweds left their flowers, a busload of Russian-speaking tourists from New York observed a moment of silence. "For two days we were still hoping, maybe, maybe, some magic would happen," said Tatyana Nazarova, who emigrated to Brooklyn seven years ago. "This is a special day, to share grief."
Others felt the same way: a family from Kansas City, Kan., a couple from Phoenix, visitors from Buffalo. An 89-year-old woman summering nearby walked slowly toward the memorial, dressed in a skirt and heels on a sweltering day, leaning on her daughter's arm. "We wanted to do something and we felt a little bit closer here," said her daughter, Crystal Rousos of Belmont, Mass.
Around Hyannis today, at a modest shingled cottage near the harbor, at an art gallery within sight of the Kennedy compound in Hyannisport, the first flags began to drop to half-staff. "Everybody assumed they wouldn't survive, but we wanted to wait until it was final," said Michael Murphy, who this morning lowered the flag at Steamers Grill and Bar.
Others who wanted to mark the latest in the stricken family's history of tragedy came to the John F. Kennedy Museum on Main Street, where attendance was three times higher than normal.
The staff placed a vase of Cape flowers and a small display of photos in one of its exhibit rooms: John Jr. as a little boy with a pony, John Jr. as a young man at his sister's wedding. The guest book, which the museum intends to turn over to the family, filled quickly with visitors' names, addresses and anguished comments.
"The tragedies and happiness of the Kennedys gives us guidance and courage to carry on," wrote a mourner from California. "Lord have mercy on you."
Staff writer Don Phillips in Washington contributed to this report.