2011 IEEE 13th International Symposium on High-Assurance Systems Engineering (2011)
Boca Raton, Florida USA
Nov. 10, 2011 to Nov. 12, 2011
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/HASE.2011.45
Turkish Airlines Flight 1951 crashed short of its destination runway at Schiphol Airport, Amsterdam, Netherlands on February 25, 2009. Nine people lost their lives, 177 were injured, and the aircraft was a complete loss. There was an equipment failure in the left radio altimeter that caused the auto-throttle system to go into retard flare mode in anticipation of immediate landing when the aircraft was still near 2000 ft above terrain, There were indications and warnings of this condition to the crew but they were ignored. The throttle retardation was also temporarily masked by the aircraft being directed to intercept the localizer from above, a highly unusual procedure. The investigation found numerous instances of low altitude readings on the accident aircraft as well as on others. Also, the accident aircraft had experienced two instances of throttle retardation on recent flights. Poor reporting practices led the manufacturer and the certifying authorities to underestimate the prevalence of this failure pattern. It is concluded that in many instances actions and design decisions were based on the assumption further conditions will be within the normal envelope. This is a dangerous assumption that must be avoided if we want to maintain the fine safety record of commercial aviation.
aircraft safety, radio altimeter, failure reporting, human factors
H. Hecht, "So Much to Learn from One Accident Crash of 737 on 25 February 2009," 2011 IEEE 13th International Symposium on High-Assurance Systems Engineering(HASE), Boca Raton, Florida USA, 2011, pp. 348-351.