Cockpit recordings reveal rattle shook jet before accident Cockpit recordings reveal jet in distress on takeoff attempt

The badly charred remains of the Continental jetliner lie on the runway Sunday at Denver International Airport. The badly charred remains of the Continental jetliner lie on the runway Sunday at Denver International Airport. Photo: PRESTON GANNAWAY, ROCKY MOUNTAIN NEWS Photo: PRESTON GANNAWAY, ROCKY MOUNTAIN NEWS Image 1 of / 3 Caption Close Cockpit recordings reveal rattle shook jet before accident 1 / 3 Back to Gallery

A cockpit recording from the Houston-bound plane that veered off a Denver runway on Saturday revealed that the flight crew aborted the plane's takeoff when a sudden bumping and rattling shook the plane about 41 seconds into its attempt to take off.

Ten seconds later, the recording stopped abruptly, probably when the plane hit the runway berm and became briefly airborne, then crashed down onto the bumpy ground, investigators said in a news conference Monday night.

The early investigation revealed no obvious problems with the plane's brakes, tires or flaps, and the cockpit recordings showed that there were no concerns about wind shear or crosswinds, said Robert Sumwalt, a member of the National Transportation and Safety Board. The runway was clear and dry, he said.

While five people remain hospitalized from the crash, including the plane's captain, investigators will continue to search for clues to what sent the plane careening off the runway and into a snowy ravine.

The captain was too injured to grant a statement to government accident investigators, officials said, but the first officer spoke to investigators at length on Monday.

Thirty-eight of the 115 people aboard were injured when the Houston-bound plane slid into the ravine Saturday and caught fire. The captain was one of five who remained hospitalized Monday.

Captain in hospital

Capt. David Butler was in serious condition at a Denver hospital Monday. He and his first officer, Chad Levang , are both based in Houston. Levang and at least one other Continental crew member were among those treated for injuries and released.

Sumwalt said investigators could clearly hear the crew's conversation before the crash in the cockpit flight recording, but he did not divulge details. The voice and data recorders have been taken to Washington for further analysis.

Investigators spent most of Monday gathering and documenting physical evidence from the plane, which remains on its belly in the snow. Sumwalt said it was vital to the investigation that all physical evidence — such as runway debris, skid marks, landing gear and cockpit settings — be recorded before the aircraft is removed.

"Our goal is to be very methodical," Sumwalt said. "To do it right, once the airplane is moved, we can't go back and say how was this switch set?"

The Continental flight skidded off course in the first 2,500 feet of the airport's 12,000-foot runway at 6:18 p.m. Saturday, Sumwalt and Denver airport officials said.

Experts said that meant problems likely began before the jet ever attained the speed necessary to leave the ground. The plane lost one engine and all of its landing gear as it careened into a ravine about 2,000 feet off the 34 Right runway — one of several extra-long runways constructed at the Denver International Airport to help compensate for the complexities of high altitude takeoffs.

Several factors studied

Sumwalt said the first officer estimated the plane was traveling at 98 to 103 mph when it began to veer off the center line of the runway. The plane achieved a top speed of about 137 mph before it crashed, he said.

The accident was the worst there in more than a decade, city airport officials confirmed.

Sumwalt said investigators were continuing to look at windy weather conditions in Denver, possible mechanical failures and the possibility of pilot error, among other factors that could have caused the crash.

The night of the accident was clear, windy and cold, according to the National Weather Service, which monitors Denver airport conditions.

Northwest winds were recorded at 21 mph — gusting up to about 32 mph just a few minutes after the crash. That is above normal wind speeds for Denver, but far from a record.

Federal Aviation Administration records revealed five reported problems with the Continental Airlines plane, which was manufactured by Boeing in 1994.

An engine malfunction back in 1995 forced an emergency landing. The plane was diverted to Denver and the engine ultimately was replaced, records show.

In 2005, a one-inch crack through a rivet where the frame joins the plane's cabin floor was discovered. The cracked area was cut out and repaired, the FAA documents show.

Eight days later, another inspection found corrosion in the frame in an aft baggage bin. That also was repaired.

In addition to examining problems with the plane, the NTSB will review injuries that occurred during its evacuation, investigators said.

Some passengers were injured as they used inflatable slides or climbed out along the wings into the snow, according to reports from witnesses. The passengers included three children under 2, who were riding without seat belts or tickets as lap children.

Final report may take a year

Former NTSB Chairman Jim Hall said Monday that the agency could take as long as a year to issue a final report.

"There also is a very strong possibility they might have a hearing on this accident," said Hall. "It sounds like there are a number of significant safety issues."

Continental spokeswoman Julie King said Monday that a majority of the passengers that were aboard have gone home or to their "chosen location."

"Our passenger and family assistance center is fully activated in Denver, and we continue to focus on assisting customers and crew members that were aboard the flight to accommodate their individual needs," she said.

Continental is working to recover the personal items of those on the flight, she added, while fully cooperating with the NTSB on its investigation.

Chronicle reporter Jennifer Latson contributed to this report.

lise.olsen@chron.com

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