Thanks Ingo, very good explanations – that’s what I love about this forum. I agree 100% with what you say about the FCOMs. They are good for what they are designed for and not if you want to dive deeper into the systems. I am a pilot-instructor/examinator/evaluator and as you understand no engineer. I try to read the maintenance manuals to learn more but don’t have your background. Ironically even the maintenance manuals can be too simplified at times. With your example the illustration you enclosed show a slightly different function than the maintenance manual's text which I quoted above – trust your illustrations.
As far as LEM's - question is concerned will the avoidance of APU pressure drop extend APU life? In some cases yes – depends on APU model ref Boeing Bulletins and Dag’s details above.
How long time should we use for our flows and starts?
The overall Boeing philosophy is to be safe and time efficient. As an example a pilot would do some 330 items from memory before start and only check about 10% by checklist to save time. The extreme oposite - a typical airforce SOP is often 100% read and do which takes much longer and probably be a bit safer?
Procedure designers must keep in mind that if an average sized airline with 30 to 40 737s who flies shorthaul use one extra minute on each leg then they will need an additional aircraft to serve their schedule. With this in mind Boeing have installed the lights which when they work should allow one pilot to monitor while the other continues the next start. I do agree that your method is better especially if you need to clear fluids after maintenance work which increases the probability of abnormal starts.
Last edited by 80/20; 22nd Nov 2004 at 20:09.