Saturday, 20th of December, 2008
– United States of America
Continental Airlines Flight 1404, a domestic scheduled passenger flight from Denver International Airport (DEN/KDEN), Colorado, to Houston-George Bush Intercontinental Airport (IAH/KIAH), Texas, operated with a Boeing 737-524, registration N18611, departed the left side of runway 34R during takeoff at Denver International Airport (DEN/KDEN), Colorado, USA.
The airplane was destroyed. The five crew members and 110 passengers survived. (115 survivors)
The crash of Flight 1404 is the fifth loss of a Boeing 737-500
Continental Airlines flight 1404, a Boeing 737-500, departed the left side of runway 34R during takeoff from Denver International Airport (DEN). The scheduled, domestic passenger flight was enroute to Houston-George Bush Intercontinental Airport, TX (IAH). There were 37 injuries among the passengers and crew, and no fatalities. The airplane was substantially damaged and experienced a post-crash fire. The weather observation in effect at the time of the accident was reported to be winds at 290 and 24 knots with gusts to 32 knots, visibility of 10 miles, a few clouds at 4000 feet and scattered clouds at 10,000 feet. The temperature was reported as -4 degrees Celsius.
The flight pushed back at 18:01. Ice and snow were visible on the ramp, so the captain started both engines and turned the engine and wing anti-ice systems on. The flight was cleared to taxi to 3W and the captain began to taxi the airplane. Approaching 3W, the first officer contacted ground control and received a clearance to taxi to runway 34R via taxiway F.
As the airplane approached runway 34R, the flight crew performed the before takeoff checklist and contacted the tower. The tower instructed flight 1404 to position and hold on the runway. The runway appeared to be clear of snow and ice, so the captain decided to de-select the engine and wing anti-ice systems but he left the engine igniters on. The captain positioned the airplane on the runway and the flight crew waited for two or three minutes. The runway lights and all of the airplane’s lights were on and runway visibility was excellent.
The tower contacted the flight crew, informed them that winds were 270 degrees at 27 knots and cleared them for takeoff. The controller’s wind report surprised the flight crew because it was higher than the wind reported in ATIS Sierra. The captain recalled saying something to the first officer like, “Roger, crosswind.” The first officer recalled the captain saying, “Winds are 270 at 27. You ready?”
The captain was the flying pilot and he began a reduced-power takeoff. He first pushed the thrust levers up to achieve 40 percent N1, then increased power to 70 percent N1. He noticed a difference in the thrust being generated by the two engines, but the two engines matched as he increased N1 to 90 percent. After verifying this, he pressed the TOGA button and called out, “check power.” The first officer responded that thrust was set at 90.9% N1. The captain applied a left control wheel correction, applied forward pressure to the yoke, and used variable right rudder to keep the airplane aligned with the runway centerline. He recalled that it felt at first like a “normal crosswind takeoff.”
The captain recalled that as the airplane was getting up to speed it suddenly yawed to the left, as if hit by a “massive gust of wind,” or as if the tires had hit a patch of ice and lost traction. He recalled using full right rudder but seeing the airplane continue to veer left. The first officer recalled that as airspeed was increasing from 87 to 90 knots he looked up and saw the airplane drifting left of the runway centerline. He thought the captain was correcting back to the right, but the airplane suddenly yawed 30 to 45 degrees to the left. It appeared to the first officer as if there was “zero directional control.” He recalled feeling the rudder pedals with his feet and he believed the captain was applying full right rudder.
The captain recalled facing the edge lights on the left side of the runway. He believed the airplane was going to exit the left side of the runway and, as a last resort, he reached down with his left hand and grabbed the tiller for a second or two. He attempted to steer the airplane back onto the runway using the tiller, but this did not work so he put his left hand back on the yoke.
The captain recalled using right control wheel to keep the wings level as the airplane departed the left side of the runway. He said that he did this because he thought the ground next to the runway sloped down and he feared that the aft end of the fuselage would slide down that incline and cause the airplane to “tumble on its side.” After the airplane had completely exited the runway, the captain said “reject” and tried to deploy the thrust reversers. He recalled that he was unable to deploy the reversers because the ride was very rough.
The airplane was subjected to two violent impacts before it came to a stop. It was totally dark inside the cockpit. Neither the captain nor the first officer recalled hearing any engine sounds. Both were stunned and in pain and they felt incapable of doing anything for one or two minutes. They did not order an evacuation or perform the evacuation checklist.
After recovering from the initial shock of the crash, the first officer opened a cockpit window to his right and threw out an escape rope, but he saw fire along the right side of the airplane and decided not to exit that way. He got out of his seat so he could exit through the cabin instead. As the first officer stood up, a deadheading crewmember knocked on the cockpit door and the first officer opened it. About this time, the captain was trying to get out of his seat as well, but a dislodged flight crew bag was blocking his path. The first officer moved the bag and he and the deadheading crewmember helped the captain out of the cockpit. The deadheading crewmember told the first officer that all of the passengers had been evacuated and then the captain, first officer and deadheading crewmember exited the airplane via the L1 slide.
“The National Transportation Safety Board determines that the probable cause of this accident was the captain’s cessation of right rudder input, which was needed to maintain directional control of the airplane, about 4 seconds before the excursion, when the airplane encountered a strong and gusty crosswind that exceeded the captain’s training and experience.
Contributing to the accident were the following factors: 1) an air traffic control system that did not require or facilitate the dissemination of key, available wind information to the air traffic controllers and pilots; and 2) inadequate crosswind training in the airline industry due to deficient simulator wind gust modeling.”
– NTSB Final Report: