Tuesday, July 21, 2009

The crash of Continental Flight 1404: Part 1, Post-crash conditions in the cabin

by B. N. Sullivan

On July 17, 2009 the U.S. National Transportation Safety Board (NTSB) made public a slew of documentation related to their investigation of the Continental Airlines Flight 1404 disaster at Denver International Airport (DEN) late last year. The investigation is still underway, and no conclusions regarding probable cause have yet been presented, but the newly released materials provide a lot of new information about the accident.

N18611The accident happened on December 20, 2008 when the Boeing 737-500 aircraft (registration N18611) veered off the left side of runway 34R at DEN during its takeoff roll. The aircraft was destroyed by the runway excursion and post-crash fire. All on board survived, although 37 among the five crew and 110 passengers were hospitalized for injuries, some serious.

A number of news reports both inside and outside the aviation community have opined about the meaning embedded in the technical information newly released by the NTSB. I will leave it to the pilots and engineers who are qualified to do so to pore through and interpret the information that emerged from the Flight Data Recorder readouts and other systems information. I will leave it to the meteorologists to draw conclusions about the wintry weather and wind gusts on that evening. Otherwise, I will wait for the NTSB's final report to determine probable cause.

I would, however, like to bring forth what I think is important information arising from the NTSB's interviews of several individuals who were on the accident flight. That information has to do with the post-crash evacuation and related survivability issues. Curiously, this information has (so far) been overlooked in press reports about the newly released documents, but I judge it to be of great interest to the crew members who are the primary audience of Aircrew Buzz.

Among the documents related to the investigation of the Continental Flight 1404 accident, one of the lengthiest is a 91-page report summarizing the NTSB's interviews with 17 individuals [link below]. Among the interviewees were the two pilots who were operating the accident flight, and two other Continental pilots who were on board as passengers, dead-heading back to their base. Their statements give the clearest picture to date of the situation inside the aircraft immediately post-crash, and what happened during the subsequent evacuation.

From the interview summaries we learn that both pilots on the flight deck were injured, the captain seriously. We learn that both were stunned by the accident, and were unable to do anything operationally in the first couple of minutes after the aircraft came to a rest. Neither initiated the evacuation of the aircraft.

The captain was interviewed four days after the accident while still hospitalized with injuries that included spinal fractures. He stated that he "was either knocked out or dazed" immediately after the crash, and did not recall how he got out of the airplane.

Both pilots recalled that the flight deck was completely dark. The first officer said that he "could hear things going on in the cabin and he thought that he needed to make a PA" but he did not. His next thoughts, he said, were about getting himself and the captain out of the aircraft.

The first officer "confirmed that the cockpit door was closed for the entire evacuation" and that by the time he opened the door, everyone was off the aircraft except the dead-heading crew and a flight attendant.

Meanwhile, back in the passenger cabin, the damage inside the aircraft was considerable, and the situation was worsened by a fire that was quickly consuming the right side of the aircraft.

The dead-heading captain (DHC) was seated in 1B, right at the bulkhead in first class. As soon as the aircraft came to a stop, he unbuckled his seat belt and although injured, assisted with the evacuation that was already underway. He gave a description of the conditions inside the cabin.

The DHC said the panels in the middle of the row "had swung down and were still swinging." He tried to keep them out of the way as people went by because he knew "they would get hurt because they swung so fast." Although people were bumping him as they passed by in the aisle, he finally got the panels up and locked into place. He then went toward the back and got three more panels locked up.

Later in his interview the DHC clarified that the overhead panels in the center aisle had fallen.
He said they hinge on the aircraft right in the aisle and they were down and swinging back and forth. He pushed it back and that was how he got hit. He said he was 6’ 3” and was holding it back and people holding babies hit him a couple of times. He jumped on the other side and pushed the panel up, got hit by another passenger and fortunately locked it back in place. He said the panels did not malfunction but just came undone.
As the fire grew more intense, the DHC could see a breach in the cabin just aft of the exit row. He saw the emergency lights on but could not see past the breach because it was dark in the back. He saw flames from the first class windows to the over-wing exit. He said he did not feel any heat initially.

The DHC then looked toward the cockpit. He saw "the forward flight attendant was standing on one leg holding herself up. The cockpit door was closed."

After assisting with the evacuation of passengers, he and the dead-heading first officer (DHFO) went to the cockpit door and it opened. The captain "was out of his seat between the pedestal and cockpit door and was in excruciating pain." The DHC said he could see that "both pilots were very injured" and that "they looked dazed from the impact." The two dead-heading pilots got the flight deck crew out of the cockpit and helped them through the L1 door.

The fire was on the right side of the aircraft. All on board evacuated through the doors on the left side of the aircraft.

All slides deployed properly, however since the landing gear had been sheared off, the door sills were not very far above the ground level. In that position, the DHFO remarked, the slides were more like a “padded walkway” than slides.

The DHFO also commented that the gray-colored slides might have been easier to see if they were bright yellow or fluorescent orange. He also said "two exits are better than one and a bigger one is better than a smaller one."

Next: Part 2, Evacuation details

Here is the link to the NTSB Interview Summaries related to the crash of CO 1404 at Denver (91-page 'PDF' file).

Here is the link to the NTSB Docket listing all of the public documents related to this accident.

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RELATED: Click here to view all posts about Continental Flt 1404 on Aircrew Buzz.