Climbing towards 35,000 ft withFD ONA/T ONThe left CMD ONThe engines began to idle at about 30,000 ft with the relevant text warning being issued.The only way I could recover power was to hit the speed switch to instruct the computer to ignore the FMC LEGS power requirement.What could have gone wrong?Cliff

>Climbing towards 35,000 ft with>FD ON>A/T ON>The left CMD ON>>The engines began to idle at about 30,000 ft with the relevant>text warning being issued.>>The only way I could recover power was to hit the speed switch>to instruct the computer to ignore the FMC LEGS power>requirement.>>What could have gone wrong?>>Cliff>>Hi Cliff,I got what you said but i need more information before we find the solution.What are the details set on the MCP ? and what about the data in the FMC ; like altitude set .....etc..There are a lot of factors which may cause the A/T to behave in that way.-NavneetFS 2004 Version 9.1AMD Athlon 64 3000+ATI Radeon 9600 128MB - Anti-Aliasing 6x1GB DDR400 Kingston RAMWestern Digital 30 GB - Seagate 120 GB (7200 rpm)Sony DVDRW - 16XLG Flatron 775FT 17' MonitorCreative SBLive! X-Gamer 5.1Creative Inspire 5.1 5200Windows XP Pro SP2 v.2180Microsoft Sidewinder Precision Pro 2Logitech Cordless Optical Mousehttp://www.precisionmanuals.com/images/forum/747400.jpg-|http://www.precisionmanuals.com|-

Writing from memory the altitude I'd set into the box was 35,000 ft and the altitude on the Legs page was 33,000 ft. And I think that possibly, while in the early stages of the climb, I might have hit "Climb Change" to hasten the climb.It may not be relevant but the following also happened: after recovering from the engine idle problem I later left the aircraft to continue part of it's longish flight(Boeing Field to Los Angeles) while I went for a walk with our Retriever. Before leaving I'd reduced to, and reached, an altitude of 10,000 ft.On my return I found that the Autopilot was no longer operating and we were in an uncontrolled, steep climb at 22,000 ft with the speed dropping severely.(Of course!)That's the second thing I find unable to explain. I should mention that, during a chat with a retired Senior Training Captain, I asked whether he found it boring during the hours of a long flight. He remarked that they were constantly checking and one of the checks was to make sure that the autopilot hadn't tripped out.Should I to assume therefore that this can happen on our Sim Flights?Regards,Cliff

Cliff-It sounds to me as though you have some type of spiking in the signal from your controls (yoke/joystick) that is being interpreted by the AFDS as you trying to take control of the airplane....In the actual airplane, applying a specific amount of pressure on the flight controls will cause the autopilot to disconnect and return control of the airplane to you. (It assumes that you are overpowering it for a reason....)Our airplane does the same, but if you have signal spiking coming from your joystick- it can cause the a/p to disconnect because it thinks you are pushing the stick around.....Your earlier comment about the engines going to idle during the climb sounds like an AFDS issue.... I'm going to bet that you instructed it to slow the airplane.... albeit accidentally.... I've done this a few times when testing things in the FMC- if you don't carefully monitor the speeds you have programmed into the fixes while in VNAV- it IS possible to have the airplane slow down unexpectedly.....Situational awareness is key....

Possible spiking is an interesting suggestion which I'll discuss with my computer guru when next we're together.Is there a way to check the validity of the idea Robert?Thanks for the idea, the explanations and for the many hours of enjoyment I've had.Before retiring I worked for an international company renowned for the quality of it's service and products. This is almost the first time that I've again experienced the same level of those two ingredients anywhere else. You and your team deserve to succeed.Well done.Regards,Cliff

Cliff,It is higly likely that :(a) You had the AT overrride option checked in PMDG menu(:( Your joystick throttle was left at the rear stop (idle position) or some intermediate low thrust position© Your USB port started for any reason bombarding Windows with info. Since AT override was checked, your command(s) regarding throttle position had a priority over the AT system (AT overrride remember ?) -- ofcourse these were not exactly your commands :)It won't happen after the forthcoming service update. The logic is changed and pilot throttle control with AT active is only allowed when the announced AT state is HOLD.Till then as Rob suggested : scan your instruments.Best,Vangelis===================================== E. M. Vaos Precision Manuals Development Group www.precisionmanuals.com=====================================

Thanks for this information Angelis. You are correct about the AT overide being checked: I've now unchecked it.It'll be most interesting to compare the aircraft after the upgrade.I've lately run into another problem that had never reared it's head before with either your 737 or 747After touchdown (using full Auotoland settings) the throttle remains at the landing speed and consequently I can't stop despite disconnecting the Autopilot.Hopefully this problem will also disappear after the upgrade.Regards,Cliff