With 280 passengers and 12 crew onboard, a Lockheed L-1011 TriStarwas being repaired for a scheduled flight from New York John F. Kennedy International Airport to SanFrancisco International Airport. With all preparations for the flight complete, push-back clearance was requested and given at 17.16 lt (local time), followed by taxi clearance to runway 31R. The copilot was the pilot flying (PF), and the captain was the pilot monitoring (PM)for the flight.
The aircraft wreckage after the fire was extinguished (Source; http://ww.crashdehabsheim.net © Unknown)
The aircraft reached the 14.572 feet long runway 13R after a short taxi, and at 17.40 lt the crew acknowledged their take-off clearance to ATC. The throttles were forwarded by the Captain, to the take-off position and the aircraft started its take-off run. The take-off was performed according to the current valid operating procedures from the airline. This meant that when the first officer was the PF the captain controlled the thrust levers until the landing gear was retracted. As the aircraft accelerated down the runway the standard call-outs were made;
At 17.40:58 the PM called out "V1"
At 17.41:03 the PM called out "VR
In response to the call-out, the PF rotated the aircraft. This was followed eight seconds later by the PF calling out "GETTIN' A STALL" when the stick shaker activated. At that time the captain assumed the role of PF. After a short exchange between the flight crew regarding the situation the captain decided to abort the take-off and pulled the throttles back to idle. The aircraft touched down hard (with a vertical speed of 14 feet/second, the design limit being 6 feet/second) after being airborne for only 6 seconds. The captain applied full reverse thrust and maximum braking, and the aircraft decelerated, however, less than expected by the captain. With approximately 1500 feet of runway remaining the aircraft still travelled down the runway at a speed of ~100 knots. The captain determined he would not be able to stop the aircraft and was under the impression the brakes were losing effectiveness, before crashing into the blast fence at the runways' end. The aircraft was turned off the runway onto the grass. Around that time the fire warning sounded, which was silenced by the flight engineer. The captain then instructed him to pull the appropriate fire handle and activate the fire extinguishers.
Aircraft tail section after recovery of the wreckage from the crash site. (Source; http://ww.crashdehabsheim.net © Bevin Shively)
When the aircraft left the runway the now landing gear collapsed backwards against the aircraft's lower fuselage. For a short distance (296 feet) the aircraft continued over the grass before coming to a stop. The engines were switched off, fire handles pulled and fire extinguishers activated. The evacuation alarm sounded and the Captain made a Public Address announcement "THIS IS THE CAPTAIN, EVACUATE THE AIRCRAFT). Evacuation of the aircraft was accomplished through the most forward door on the right and the two forward left doors. All occupants left the aircraft, the Captain being the last after he inspected the cabin if everybody had left the cabin. One passenger sustained serious injuries, nine passengers sustained minor injuries. The aircraft was destroyed by fire, although the fire brigade was on the scene of the accident within two minutes after the aircraft came to a stop, the estimated value of the aircraft was $12.000.000 to $13.000.000. During the investigation by the National Transporation Safety Board (NTSB), it became apparent that the right Angle of Attack (AOA) sensor had experienced 9 previous malfunctions. The intermittent malfunction was not detectable during pre-flight system tests by the pilots and didn't trigger a fault light. This permitted the sensor to cause a false warning when the air-ground sensor on the landing gear went into the air status on takeoff.
The wreckage after being removed from the crash site. (Source; http://ww.crashdehabsheim.net © Bevin Shively)
The probable causes for the accident were identified as;
Design deficiencies in the stall warning system that permitted a defect to go undetected,
The failure of TWA's maintenance system
Inadequate crew coordination between the captain and first officer that resulted in their inappropriate response to a false stall warning.
The full NTSB report (117 pages) with detailed information on the accident is available for your reference by clicking here.
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