Text-only reference. Published from the recorded official FAA General Chapter 14 PDF. Diagrams, photographs, and figure artwork are not reproduced here; use the official FAA PDF for those materials.
14-30 On March 20, 2001, a Lufthansa Airbus A320 almost crashed shortly after takeoff because of reversed wiring in the captain's sidestick flight control. Quick action by the co-pilot, whose sidestick was not faulty, prevented a crash. The investigation has focused on maintenance on the captain's controls carried out by Lufthansa Technik just before the flight. During the previous flight, a problem with one of the two elevator/aileron computers (ELAC) had occurred. An electrical pin in the connector was found to be damaged and was replaced. It has been confirmed that two pairs of pins inside the connector had accidentally been crossed during the repair. This changed the polarity in the sidestick and the respective control channels “bypassing” the control unit, which might have sensed the error and would have triggered a warning. Clues might have been seen on the electronic centralized aircraft monitor (ECAM) screen during the flight control checks, but often pilots only check for a deflection indication, not the direction. Before the aircraft left the hangar, a flight control check was performed by the mechanic, but only using the first officer’s sidestick.
Incident Cause Lock pin Alaska Airlines Flight 261, a McDonnell Douglas MD-83 aircraft, experienced a fatal accident on January 31, 2000, in the Pacific Ocean. The two pilots, three cabin crewmembers, and 83 passengers on board were killed and the aircraft was destroyed. The subsequent investigation by the National Transportation Safety Board (NTSB) determined that inadequate maintenance led to excessive wear and catastrophic failure of a critical flight control system during flight. The probable cause was stated to be “a loss of airplane pitch control resulting from the in-flight failure of the horizontal stabilizer trim system jackscrew assembly’s acme nut threads. The thread failure was caused by excessive wear resulting from Alaska Airlines’ insufficient lubrication of the jackscrew assembly.” Accident Cause crashed due to reversed wiring of the flight controls.
crashed due to insufficient lubrication of the jackscrew assembly. MAINTENANCE JOB CARD WORKNO A26 AD-NOTE 1 OF 2 -400 1 OF 1 97471 FZE 1 ZONE 221-222 SOLID STATE FLIGHT DATA RECORDER (IF APPLICABLE) MS 31-31-00-007-002-500 (AMM 31-31-01)F1 SSFDR DATA COPY NOTE: THIS IS A DUPLICATE INSPECTION! PERFORMANCE AND INSPECTION MUST BE DONE BY TWO PERSONS. PERFORMANCE = B1 INSPECTION = B1 Make a copy of the FDR data with the portable interface (PI) unit A General (1) This taskwork the hand-hold portable interface (PI) unit to make a copy of the data from the flight data recorder (FDR) when the FDR is in the airplane (a) The PI puts the data on a removable PC card (PCMCIA).
(b) The data on the PC card can then be analyzed by the applicable airline personnel. 1 0.00 0.00 SSFOR - PORTABLE INTERFACE UNIT JOB 4A D-4 FRAWB41 18.11.02 263 PAC UZ0030 explains the steps of each maintenance task. Federal Aviation Administration (FAA) There are a number of human factors resources within the FAA. The most direct link for aviation maintenance human factors is the FAA Human Factors website at hf.faa.gov. It offers document access and services, including most of the FAA maintenance human factors documents dating back to the 1988 start of FAA’s maintenance human factors research and development program. New documents include videos, PowerPoint presentations, and other media.
FAA’s Maintenance Fatigue Section The FAA has sponsored a multi-disciplinary subject matter expert work group involving industry, labor, research, and government to investigate the issues associated with maintenance fatigue, and the practical science-based methods that can be used to manage fatigue risk. For more information, visit the website at www.mxfatigue.com. 14-31 TECHNICAL CAUSES HUMAN CAUSES 1903 Present 100 90 80 70 60 50 40 30 20 10 0 Accidents Time Accidents in Aviation FAA Safety Team The FAA Safety Team has a dedicated website that provides up-to-date information safety concerns, upcoming seminars, featured courses and resources. For more information, visit the website at www.faasafety.gov.
Other Resources System Safety Services The mission of System Safety Services is to assist clients in developing the best possible safety system to meet their needs. They have an experienced and professional team of individuals with years of experience in aviation and human factors. The website provides a lot of information on human factors including articles, upcoming events, presentations, safety videos, training aids and workshops. For more information, visit their website at www.system-safety.com. Human Factors & Ergonomics Society (HFES) The Human Factors and Ergonomics Society (HFES) is the only organization in the United States dedicated specifically to the human factors profession. The HFES was formed in 1957 and typically maintains about 5,000 members. For more information, visit their website at www.hfes.org.
International Ergonomics Association (IEA) The International Ergonomics Association (IEA) is a federation of over 40 ergonomics and human factors societies located all over the world. All members of the HFES are automatically also members of the IEA. The main contact point within the IEA is through the office of their Secretary General. For more information, visit their website at iea.cc.