Overview

• Introduction
• Accident Report Results
• Accident Review Results

From the literature, comments from the experts we surveyed, news media, and other sources, we identified 34 aircraft accident reports that we thought might contain evidence related to the flight deck automation issues. We were able to obtain 20 of these reports from the US National Transportation Safety Board and other national and international agencies that conduct accident investigations. We reviewed these reports, looking for statements by the investigating board identifying one or more of the flight deck automation issues as contributing to the accident. We have since identified and reviewed 11 additional accident reports for a total of 31 reports reviewed.

The strength we assigned to the statements we identified as evidence in the reports was based on how close the investigating board's findings were to one of our issues and on the extent to which the problem they described contributed to the accident or incident (or at least how confident the board was that it contributed to it). We used the following table for assigning strengths to accident/incident evidence.

In the table, the phrase "equivalent to issue statement" means that the board's description of the problem they discovered in their investigation was approximately the same as the problem suggested by the issue statement of one of the flight deck automation issues. The phrase "similar to issue statement" means that their description did not quite match the issue statement but that their essential meaning seemed to be the same, or that it seemed to the analyst that the investigating board described a problem very similar to that suggested by the issue statement. The phrase "analyst unsure" means that the analyst thought that the board had implied one of the issues in the accident but the way the board worded its findings was ambiguous.

The investigating board's statement that a problem's contribution to the accident/incident was "probable" means that the board determined that it was a major contributing factor in the accident, while "possible" means that it was merely a contributing factor or possibly just one of the board's hypotheses. In the same column, "analyst unsure" means that the analyst could not determine from the description how significant the board found the problem to be, but that the board at least seemed to imply that it could have played a role.

For example, if we read that a board investigating an accident concluded that the flightcrew's lack of understanding of the flight level change mode of the aircraft's autoflight system contributed to the accident -- but was not its probable cause -- we would record evidence for issue105 with strength +4.

We did not look for or find contradictory evidence in accident reports. An accident or incident investigation is not an experiment and the fact that an investigating board finds that, for example, the pilots of an accident aircraft were thoroughly knowledgeable in the use of autoflight system and that lack of knowledge did not contribute to the accident is not evidence that all (or even most) pilots thoroughly understand the automation they use.

The following is a list of the aircraft accidents in which we found evidence related to the flight deck automation issues. The accidents are listed alphabetically by air carrier and include links to the bibliographic information and evidence found in the reports:

In addition to accident reports prepared by official investigating boards, we included several accident reviews in our study. These were reviews conducted by qualified individuals after the official investigations, which benefited from additional information and the perspective offered by the individual's field of technical expertise. Although we assigned lower strength ratings to evidence from such accident reviews, they were nevertheless a valuable supplement to evidence from the accident reports.

The following is a list of the accident reviews in which we found evidence related to the flight deck automation issues. The list includes links to the bibliographic information and evidence found in the reports: