Incident Lockheed L-1011 TriStar 1 N707DA,
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ASN Wikibase Occurrence # 223903
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Date:Tuesday 12 April 1977
Type:Silhouette image of generic L101 model; specific model in this crash may look slightly different    
Lockheed L-1011 TriStar 1
Owner/operator:Delta Air Lines
Registration: N707DA
MSN: 1077
Fatalities:Fatalities: 0 / Occupants: 52
Aircraft damage: Minor
Location:Near San Diego International Airport - KSAN -   United States of America
Phase: Take off
Nature:Passenger - Scheduled
Departure airport:San Diego International Airport, CA (SAN/KSAN)
Destination airport:Los Angeles International Airport (LAX)
Confidence Rating: Information is only available from news, social media or unofficial sources
During takeoff, the Lockheed L-1011's left elevator became stuck in a fully upwards position, leading to the aircraft pitching up aggressively and causing the aircraft to lose speed and nearly stall. The pitching force, unable to be overcome by fully pushing the control column down, was counteracted by reducing the thrust on the L-1011's wing engines but not the tail engine. The differential thrust pitched down the nose of the airliner and allowed the pilots to land the aircraft.

- Probable Cause :
"The pressurization and depressurization of the L-1011 during flight cycles caused water to be pushed inside a bearing, heavily corroding it and causing the malfunction"

Water from rain, fog and mist had dripped down a structure in the tail onto a bearing. As the plane had repeatedly ascended and descended during many flights, changes in pressure had sucked the water into the bearing. The bearing corroded and broke. When the Captain maneuvered his flight controls just before takeoff, the elevator, linked to the broken bearing, jammed.

Within hours, Lockheed contacted airlines all over the world currently flying the L-1011, warning them to check the bearing. (Several were found full of water and beginning to corrode.) Within days, the FAA issued an Emergency Airworthiness Directive making the check mandatory in the United States. On June 5, 1977, even after making the check, a British Airways L-1011 experienced a similar, though less severe, control problem. Taking off from Ailcante, Spain, the British plane, loaded with 160 passengers and headed for London, managed to divert to Barcelona and land safely. The FAA then ordered a visual check of the elevator before ANY L-1011’s next takeoff. Lockheed has since devised a deflector to drain water away from the bearing.

NTSB (Photos)

Revision history:

12-Apr-2019 17:05 Captain Adam Added
26-Mar-2023 15:20 SANMJN Updated [Location, Damage, Narrative]
26-Mar-2023 15:21 harro Updated [Damage]

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