Robot Finds EgyptAir’s 2 Black Boxes

A robot submarine located EgyptAir Flight 990’s two “black box” recorders on the ocean floor Friday, but the devices apparently were buried beneath mud or debris, and the robot did not recover them.

The Deep Drone continued its efforts into the night, using sonar and a television camera to home in on audible “pings” being broadcast by locater transmitters on the cockpit voice recorder and flight data recorder.

“They have had no joy in finding either of the pingers just yet,” said Navy Capt. Bert Marsh. “But they know they’re there.”

Late Friday, bad weather forced officials to temporarily suspend recovery operations for at least a day.

It is hoped that the recovery of the recorders will provide National Transportation Safety Board investigators with key evidence about why the Boeing 767 crashed Sunday. The voice recorder retains the last 30 minutes of sounds inside the cockpit. The data recorder logs information on dozens of technical aspects of the flight, such as altitudes, airspeeds, headings and control settings.

Thus far, only small pieces of floating debris and fragmented human remains have been recovered, and the cause of the crash is largely a matter of speculation.

All 217 people aboard Flight 990 were killed when the jumbo jet apparently dived from 33,000 feet to 16,000 feet, climbed to 24,000 feet and then dived again, probably breaking up before it plunged into the sea about 60 miles south of Nantucket Island.

The investigation into the crash began slowly, so optimism was high Friday morning when a break in the stormy weather permitted the Navy salvage ship Grapple to return to sea and resume the search for the recorders.

The ship anchored over the debris field and the tethered robot, guided by a civilian technician aboard the Grapple, dropped 260 feet to the ocean floor.

The water is so deep and murky that sunlight does not reach the bottom. Visibility, even in artificial light, was limited to about 6 feet. But Deep Drone, using its sonar, headlights and television camera, began to search for the boxes--each about the size of a rural mailbox.

The robot found one of the jumbo jet’s wheels. It found numerous small pieces of shattered debris. It did not find either of the recorders.

But when the pinging sounds became so loud that the technician had to tear off his headset, the men aboard the Grapple knew they had found the area where the two boxes were buried. Marsh said they probably were about 15 feet apart.

Using its two robotic arms, Deep Drone began clawing at the smooth, sandy ocean floor in an effort to find the boxes and dig them up.

Marsh said that if the boxes are not too heavy or tangled in debris, Deep Drone can grasp them, one at a time, and swim with them to the surface. If they prove too much of a burden for the robot, Deep Drone can wrap each of them in a cable and a crane can haul them up.

NTSB Chairman Jim Hall said that to make sure their environment is kept as stable as possible, the recorders will be placed in saltwater-filled containers before being flown to the agency’s laboratories in Washington. He said NTSB experts there would work around the clock to extract information from the devices.

There are a number of theories about what might have caused the crash, but very little evidence to support any of them. Each has its adherents and detractors in the aviation community, and none provides a simple explanation as to what might have happened.

One theory is that the plane suffered a sudden failure of some major mechanical component such as a thrust-reverser, which can make an engine push backward instead of forward; or problems with the horizontal stabilizer, the wing-like part of the tail that controls the pitch of an aircraft. Radar data don’t seem to support either of these scenarios very well.

Another possibility centers on failure of the jetliner’s autopilot. Barry Schiff, a retired commercial airline pilot and aviation safety consultant, questioned this scenario because, in the event of autopilot breakdown, a pilot can switch to flying the plane manually as easily as an automobile driver can switch off cruise control.

A third theory involves a takeover by someone on the plane that incapacitated the pilots and left no one at the controls. EgyptAir has said that everyone on board--including several Egyptian military guards--was screened for weapons.

And there’s still the bomb theory. None of the floating wreckage discovered thus far shows any signs of fire, but experts pointed out that many types of commonly used explosives don’t ignite fires. In fact, dynamite and other explosive compounds using nitroglycerin often are used to blow out fires.

“The whole thing is like a puzzle,” Schiff said. “We’ve just opened the box it came in, and we’ve only looked at a few of the pieces. Right now, it’s awfully hard to figure out the whole picture.”