Development of a Scoring Algorithm for Flight Crew Intervention Credit in System Safety Assessments

摘要

According to current regulations for type certification of large commercial aircraft, certification credit may be taken for correct and appropriate action for both quantitative and qualitative assessments provided that some general criteria are fulfilled. According to the same regulations, quantitative assessments of the probabilities of flight crew errors are not considered feasible. As a consequence, the system designer is allowed to take 100% credit for correct flight crew action in response to a failure. Earlier research has indicated that this leads to an overestimation of flight crew performance. The overall goal of this research effort was the development of a method that would allow certification credit for good human factors design practice in certification regulation. This method consists of a scoring algorithm that combines key flight deck design characteristics into an overall level of certification credit for flight crew intervention in the case of system failures. The method is easy to apply, provided that the system failure modes are associated flight deck annunciations are known. As expected, application of the method to a number of example cases shows that it differentiates between system failures and between aircraft types. The method also produces higher average scores for more modern cockpits. Although every possible effort was spent in making this a valid, practicable, and acceptable method, it is still the result of a research project. Further development is recommended.