Experts say no common thread in in-flight crashes

COVERAGE Top story Feb. 1 Crash investigation focuses on jet's stabilizer Experts say no common thread in in-flight crashes Alaska employees choke back tears as they deal with loss At airports, grief and relief follow news of crash Jan. 31 Alaska Airlines jet crashes off California In rising swells and spreading oil, boats search for plane, people  REALVIDEO Feb. 1 Recording of final minutes of Flight 261 is released NTSB briefs press on crash Tragedy strikes Alaska Airlines Search and rescue mission continues off Calif. coast Officials address public regarding crash Jan. 31 Alaska Airlines Flight 261 crash This video clip is viewed using RealPlayer. Get RealPlayer | Help  THE VICTIMS List of passengers and crew aboard Flight 261 Biographical sketches of several passengers  ABOUT THE PLANE A look at McDonnell Douglas's MD-80 series More from the Boeing Web site  ABOUT ALASKA AIRLINES Alaska Airlines Web site Has its roots in a three-seat shuttle service begun in 1932 between Anchorage and Bristol Bay, Alaska. The service merged with Star Air Service in 1934 and, after several more mergers, adopted the name Alaska Airlines. With deregulation in 1979, Alaska began expanding throughout the West Coast and within a decade had tripled in size. Alaska now carries more than 12 million customers per year, and its route system serves more than 40 cities in Alaska, Canada, Mexico and five Western states. Alaska says its fleet of 88 Boeing jets is the youngest among all major airlines. Alaska planes are distinctive for the image of an Eskimo painted on their tails. Source: Associated Press  CRASH TIMELINE Reconstruction of the crash of Flight 261 Following is summary of the last radio exchanges of Alaska Airlines Flight 261, as described by John Hammerschmidt of the National Transportation Safety Board. These are not direct quotes from pilots and controllers, but are based on what the NTSB called a  rough transcript.  Times are Pacific Standard. 3:55 p.m. Last routine transmission before problems are reported. Los Angeles ATC (air traffic control center located in Palmdale, Calif.) clears Flight 261 to head for San Francisco at 31,000 feet. 4:10 p.m. Flight 261 advises it is having control difficulties and descends to 26,000 feet. Seconds later Flight 261 reports it is at 23,700 feet. Discussion about pilots having trouble controlling the plane. 10 second later ATC asks Flight 261 what altitude it wants to maintain. 4:11 p.m. ATC asks Flight 261 its condition. Flight 261 advises it is "kind of stabilized," in Hammerschmidt's words, and is going to do some troubleshooting. Flight 261 asks for clearance to fly between 20,000 and 25,000 feet. ATC gives clearance. 4:14 p.m. ATC asks if Flight 261 needs anything. Flight 261 responds that pilots are still working on the problem. Seconds later Discussion between air traffic controllers about handing off control of plane from one sector to the next. 4:15 p.m. ATC traffic control hands off to a new controller who was aware of its problems. Seconds later Flight 261 advises it has a jammed stabilizer and difficulty maintaining altitude. Pilots think they can maintain altitude and land at Los Angeles International Airport. 4:16 p.m. Flight 261 cleared to land at LAX. ATC asks if flight needs a lower altitude. Flight 261 says it needs to get to 10,000 feet and change configuration -- set the wing flaps to slow the plane down -- while over water. ATC issues clearance to 17,000 feet. Flight 261 says OK and advises it needs a block of altitudes. Last known transmission of Flight 261. 4:17 p.m. ATC advises Flight 261 to contact another sector on a different frequency. Transmission not acknowledged. 4:21 p.m. Flight 261 is lost off radar. Source: Associated Press

WASHINGTON -- Flying at or near cruising altitude is the safest part of a plane trip, but a surprising number of jetliners have recently crashed during that phase of flight -- the latest Alaska Airlines 261.

Those accidents have claimed nearly 900 lives over the last five years.

But aviation experts emphasized Tuesday that there is no common thread to these accidents -- as many as a half dozen since 1996. And while the causes in some cases have yet to be determined, the suspicions range from electrical failure to mechanical control problems to sabotage by a pilot.

Early indications from the crash of the Alaska Airlines MD-83 were that a mechanical problem with a control device -- the horizontal stabilizer -- may have caused the jetliner to plunged 17,000 feet into the Pacific off southern California. All 88 people aboard were presumed dead.

"Most accidents and fatalities happen during approach, landing or takeoff," says Stuart Matthews, president of the Flight Safety Foundation, a nonprofit air safety advocacy group.

A study by the Boeing Company, that examined fatal airliner crashes over a 10-year period, found that 9 percent of the accidents were at cruise altitude. Nearly seven of every 10 crashes occurred in either takeoff and early climb or in final approach or landing.

But since 1996 there have been five major air crashes where the problems began when the aircraft were at or near cruise altitude, sometimes well into their flight.

That was the case with Alaska Airlines Flight 261, which reported problems Monday during a flight in clear weather from Puerto Vallarta, Mexico, to San Francisco. It fell from 17,000 feet into 300 to 750 feet of ocean after the pilot suddenly reported a control problem.

"The aircraft no doubt was cruising along minding its own business ... when it got into some problems," says Matthews, although little is yet known for certain of what triggered the problem.

On July 17, 1996, TWA Flight 800 was climbing gradually after taking off from New York City and well along in its flight when it exploded at about 13,000 feet. All 230 people aboard were killed. While the investigation has yet to be completed, an electrical spark is widely believed to have caused a fuel tank explosion.

Last October, Egypt Air Flight 990, a twin-engine Boeing 767, was cruising at 31,000 feet off Nantucket, Mass., when it suddenly dove, and plummeted at breakneck speed into the cold Atlantic, killing all 217 people aboard. The reason for the dive is still a mystery.

About two months earlier, on Sept. 2, 1998, Swissair Flight 111, was also cruising along a similar route on a flight from New York to Geneva when it crashed off Nova Scotia, killing the 229 people aboard. While the investigation continues, an electrical problem is suspected.

Investigators are still not certain what caused a Boeing 737, belonging to SilkAir, to fall out of the sky from cruise altitude and crash into a muddy river in Indonesia in December 1997. There is some suspicion the pilot may have crashed the plane in a suicide.

And in May 1996, ValueJet Flight 592, with 110 people aboard, was climbing well beyond its takeoff, though still climbing, when it crashed into the Everglades. Investigators said hazardous cargo caught fire, causing the crash.

While still very rare events considering the thousands of airline flights that are made daily, these half dozen accidents accounted for a total of 978 deaths.

`We don't see any common threat in these accidents," emphasized Capt. Dwayne Woerth, president of the Air Line Pilots Association, in an interview.

He added, "The higher you are usually the safer you are" because pilots have more time to react to trouble. But he said these accidents demonstrate that "in every phase of flight there's nothing we can overlook. ... Things can happen even at high altitude."