Hi There, Subject 744After takeoff and within one minute of the clime the autopilot keeps disengaging, and the engine noise increases to quite a high pitch, this noise continues until the decent reaches 7000 ft.On levelling out, still the autopilot disengages, also on the approach once again disengage, that

Sounds to me like you're missing something in the FMC. Do you get any FMC messages/warnings when you try to engage the AP? I don't know about the localizer and glide slope problems as "trouble" could be "anything", hehe.

Duncan,One of the things with complex airplanes like this is that the autopilots are very complicated. There have been some questions in the forum about A/P and FMC behavior, but so far I have found that the autopilot and the FMC behave very nicely if they are set up right. I am still experimenting with different scenarios.I would suggest you setup the FMC completely and correctly with a flight plan, then try again. If you have problems, capture screens showing the PFD messages (which show which mode the autopilot is in for Thrust, lateral Nav and vertical nav) and then we will be able to help you.- Neeraj.