PROBERS NOSING INTO NOSE GEAR FLIGHT 292 NOT FIRST TO HAVE TROUBLE.

Byline: Josh Kleinbaum and Charles F. Bostwick Staff Writers

The twisted front wheel that forced JetBlue Flight 292 to make an emergency landing at Los Angeles International Airport was at least the seventh such problem on an Airbus A320, documents obtained Thursday show.

The Federal Aviation Administration and the National Transportation Safety Board are investigating the malfunction that occurred Wednesday when an entire nation was captivated by the dramatic, televised landing of the crippled aircraft with 145 people aboard.

The problem is similar to ones that prompted FAA modification and maintenance orders in 1994 and 1999, but then continued to occur, records show.

``There have been previous incidents and some recommendations were made,'' Howard Plagens, the NTSB's lead investigator into the incident, said Thursday. ``We're examining those closely.''

The NTSB will ship the problematic nose-gear assembly to New York's John F. Kennedy Airport, which is JetBlue's hub, and then dismantle it to determine the problem. The agency also will interview the plane's six crew members, who have been instructed not to talk publicly until after they are debriefed.

Nose-gear problems on other A320s have been blamed on software in a braking-and-steering control unit; on aging O-ring seals on a valve; on a malfunctioning landing-gear control-interface unit; and on a misinstalled shock absorber, records show.

The FAA also was told in 1999 that the braking-and-steering control unit could rotate the nose wheels if the valve to which the O-ring is attached fails, but records indicate that unit has not been modified.

``Airbus had indicated ... that it is considering a modification to the BSCU (braking-steering control unit) that will maintain the nose gear in the neutral position in flight,'' a 1999 FAA report reads.

Airbus has made several changes to its maintenance guide as a result of the 1999 incident, but the NTSB's preliminary investigation shows no mechanical changes to the plane itself, Plagens said.

Airbus officials would not comment on the 1999 reference to modifying the BSCU, but they are convinced the A320 is safe.

``We are not worried,'' Airbus spokeswoman Mary Ann Greczyn said in an e-mail. ``The situation is rare, though flight crews are trained to handle it and our aircraft are designed and built to withstand it.

``The outcome of (Wednesday) night's situation was exactly as Airbus anticipated - a safe landing with no injuries.''

Plagens said the NTSB will examine maintenance records of all A320s to determine whether the nose-gear problems constitute a pattern. Airbus Industrie in France has manufactured more than 1,400 of the twin-engine jets.

``We'll look at these other incidents and see where it takes us,'' Plagens said. ``If there's a pattern, we'll certainly do something.''

Aviation expert John Nance said malfunctions could be recurring because the earlier modifications weren't sufficient or the fix wasn't done to all the airplanes, or a different set of problems could be occurring.

Nance said he doubts that the Flight 292 malfunction was a result of failure by JetBlue to follow required maintenance procedures.

``It wouldn't be characteristic of JetBlue. They've got very good maintenance,'' said Nance, an author and former Alaska Airlines pilot who flew Boeing 737s.

Because of redundant safety factors built into modern airliners and airlines' maintenance practices, Nance said he was surprised the malfunction occurred.

But he said he was not surprised the plane landed safely and with little damage to the aircraft itself, since its main landing gear was working and the rudder was functioning.

``The outcome was not in doubt,'' Nance said.

Officials released more information Thursday on the three-hour flight out of Burbank's Bob Hope Airport, which ended with a dramatic landing on an auxiliary runway at LAX.

The jetliner, nicknamed Canyon Blue, pulled out of its gate at Bob Hope Airport at 3:17 p.m. and left the ground 14 minutes later.

As soon as it left, at 3:31 p.m., a fault-detection light in the cockpit alerted Capt. Scott Burke to a problem with the landing gear shock absorber. At 3:32 p.m., a second fault light indicated that there was a problem with the nose-wheel steering.

Burke steered the plane toward Palmdale, where he could circle while consulting with experts from JetBlue's New York base.

Soon after, Burke flew the A320 to Long Beach - JetBlue's Los Angeles hub, where the airline had the most local mechanics - and flew low past the tower so people could see whether the nose gear was really down.

Until then, he couldn't be sure the problem was anything more than a faulty sensor light.

After ground crews confirmed that the front wheel was extended and cocked 90 degrees, Burke and JetBlue officials decided to land the plane on LAX's long, wide runway.

Burke circled over the Pacific Ocean, burning fuel to lighten the plane. The flight crew rearranged luggage and passengers to put as much weight at the back of the plane as possible, so Burke could keep the front elevated as long as possible once he landed.

Flight 292 was moving at 140 mph when it touched down on Runway 25 Left at 6:20 p.m. When the nose gear touched down, the tires collapsed and caught fire, followed by the magnesium wheels.

The plane stopped 10,000 feet into the 11,000-foot runway.

``This was certainly a best-case scenario, but it was also what many observers, people familiar with aviation, expected to happen,'' FAA spokesman Donn Walker said. ``JetBlue has some of the best-trained pilots in the world and some of the best-trained flight attendants anywhere, and that is one of the most common simulator events.''

Josh Kleinbaum, [phone]

josh.kleinbaum(at)dailynews.com