Prototype helicopters at the Bristol Aeroplane Company have been produced and servicing schedules have been made up detailing the maintenance work and inspection that has to be carried out after the following periods : (a) between flights, (b) daily, and (c) after 30, 60, 120 and 240 hours flying.

At the time these schedules were made it was not fully realised that the work would not be carried out exactly in this way.

We now learn that the airline operators are dividing their 30, 60, 120 and 240 hour inspection and maintenance schedules into small parts. One of these parts is added to the routine daily inspection, and so, by the time 240 hours of flying have been completed the whole of the interim schedules have also been completed, without withdrawing the helicopter from service. This system can only be operated providing that all work in the schedules can be split into tasks of less than, say, three hours each; there must, of course, be exceptions as obviously the overhauling of an engine takes longer than three hours.