Interesting final report
on the Feb. 25, 2009 crash of Turkish Airlines Flight 1951, which identifies a combination of a malfunctioning radio altimeter and some human error in the crash of the Boeing 737-800 that killed nine. The report makes 11 total recommendations, including three that focus on the importance of data collection and reporting.
Investigators found that safety programs that rely so much on data collection and analysis are only as good as the data collected and analyzed, and the work done to date on the radio altimeter in question leaves a lot to be desired. Said the Dutch safety board:
Despite the fact that Boeing and the Federal Aviation Administration of the United States of America had been aware for many years that the radio altimeter system was causing many problems and was affecting the operation of other systems, this situation was not designated as a safety risk. Reports of problems with the radio altimeter system that could not be resolved by Boeing justified an effort to analyse the radio altimeter system and other related systems. Boeing and the Federal Aviation Administration of the United States of America could have recognised the fact that the problems caused by the radio altimeter system, especially the potential for activating the autothrottle retard flare mode, posed a safety risk.
Most of the problems regarding the radio altimeter system were not reported. If the manufacturer had received more reports, Boeing might have recognised the need for renewed analysis.
Investigators could not determine why the plane's altimeter malfunctioned. Read the full report here (.pdf)