Probe of Boeing 737-500 Excursion Continues

Jan. 13, 2009
Investigators still searching for cause of unusual rattling sound on cockpit voice recorder.

National Transportation Safety Board investigators continue to probe the

Dec. 20, 2008 excursion of a Boeing 737-500 (N18611) at Denver International

Airport (DEN).

Continental Airlines Flight 1404 was taking off for Houston's Bush

Intercontinental Airport (IAH) when the accident occurred. The jetliner was

substantially damaged after the flight deck crew tried to abort the takeoff,

exited the runway and ended up in a ____ in flames.. The plane carried 110

passengers. Thirty-seven people were injured.

The NTSB said there were 24-32 knot crosswinds at the time, fueling

speculation that weather may have played a role in the accident. But an NTSB

spokesman said that the crosswinds were not so strong that the pilot would not

have been able to take off.

Other factors, such as mechanical failure or pilot error, may have also

played a role.

Federal investigators said that an unusual rattling sound can be heard on

the cockpit voice recorder. NTSB officials are still trying to determine what

caused the unusual sound.

Lead NTSB investigator Bill English said the plane's flight data recorder

revealed that the thrust-reversers on both engines had been activated.

Investigators found no problems with the plane's engines, tires or brakes. The

Boeing 737's control surfaces -- including flaps, slats and speed brakes -- were

in proper position. There was no debris on the runway, which was bare and dry.

The copilot revealed that the jet began drifting off the center of the

runway as it reached about 103 mph. Safety Board officials estimate the aircraft

reached a maximum speed of more than 135 mph before veering off the runway and

ending up in the ravine.

Thee rattling sound was first heard 41 seconds after the plane started

down the runway. Four seconds later, one of the pilots called for the takeoff to

be aborted.