Health monitoring of helicopters - A framework for decision making based on health information

摘要

Health monitoring systems (HUMS) have been introduced in offshore helicopters to improve the safety risk. Failures have been detected, but the systems' ability to reliably predict failures is dominated by alerts which do not represent actual failure states. This generates a situation of frustration among those operating HUMS, as well as senior management, users of helicopters and authorities. In the present paper we will show that one of the fundamental sources for theunsatisfactory situation is the lack of a consistent framework for the decision making process in the presence of uncertainty. The existing concept implicitly assumes deterministic relationships. The significant degree of uncertainty is not properly addressed, leaving the decision-makers with a responsibility, but without guidelines and open to hindsight, post-outcome criticism. We are proposing a framework based on decision influence diagrams, which allows for consistent decision making in the presence of uncertainty inherent in the monitored failure mechanisms. This framework could form a basis for a consistent and documented definition of the decision process and a platform for unified dialogue between involved parties.