This paper deals with the problem of operating a large fleet of transport aircraft and managing the problems that arise from mechanical and avionic defects in the machines.

We, in BEA, for a long time made the common mistake of treating this mainly as a technical problem, requiring for its solution a thorough analysis of defect sources followed by engineering modification action. After pursuing this course for a number of years it became apparent that, although results were achieved, more important influences were nullifying the benefits. A wider analysis of the problem was, therefore, undertaken which made it clear that the primary problem was the management of ground operations at the London hub of BEA's system. At this point the effort of the three operating departments (Flight Operations, Engineering and Traffic) converged and had to be effectively integrated.