Science helped find Kennedy wreckage

Topeka Capital-Journal, The, Jul 22, 1999 by LESLIE MILLER

The Associated Press

OTIS AIR FORCE BASE, Mass. -- There were no apparent witnesses to the plane crash of John F. Kennedy Jr. No flight plan. No radio contact.

Yet using radar analysis and sonar, rescuers in a few short days narrowed 9,000 square miles of ocean to a few thousand square yards where the plane had gone down.

Federal aviation officials began by determining from radar readings one of the last locations of Kennedy's plane Friday night -- at 1,800 feet, about 17 miles west of the Martha's Vineyard airport.

Wreckage that washed up near the island's shores, including luggage, a headrest and other pieces of the plane, provided other vital clues.

Researchers from the National Oceanic and Atmospheric Administration used computer models to determine how far the wreckage drifted, based on winds, tides and ocean currents.

The computer pinpointed where the wreckage would have been 18 hours earlier in a process known as hindcasting -- think of forecasting in reverse. NOAA does the same thing in oil spills to determine where a leak may have originated.

The computer models generated a search grid of 4 miles by 6 miles, or 24 square miles.

The Rude (pronounced "Rudy") and the Whiting, two NOAA vessels that are generally used to survey coastal waters and make nautical charts, began Monday using a technique known as side-scan sonar to detect objects on the ocean floor.

Sonar, which stands for Sound Navigation and Ranging, sends out sound signals and analyzes the echo that bounces back.

Like a gardener mowing a lawn, the ships meticulously plied every corner of the target area, covering about 6 to 8 square miles a day, said Sam De Bow, commander with the NOAA corps.

The sonar detected about 18 objects with edges that were straight -- in other words, manmade objects.

Divers from the Navy and Massachusetts State Police determined a handful of those objects were merely boulders. But they couldn't be sure about some others, since they could only spend about 15 minutes in the murky water during each dive.

It was an ROV -- an underwater remote-operated vehicle, with lights and camera -- that found what divers couldn't. At 11:30 p.m. Tuesday, the ROV identified a fuselage as that of Kennedy's Piper Saratoga, 116 feet below the surface.

The technology used wasn't new -- it was honed during the search for wreckage of the 1998 Swissair and 1996 TWA airline disasters.

But De Bow said the search for the Kennedy plane was remarkably swift, "especially for the size of the aircraft."

"I think it was confirmation that we knew what we were doing," De Bow said. "And it confirmed that we'd done everything right and we were pretty proud of the effort."