Some trivial things to check: Are you 100% sure you are in the APP mode? Is it possible there is a 500 ft showing in the MCP altitude window?Michael J.WinXP-Home SP2,AMD64 3500+,Abit AV8,Radeon X800Pro,36GB Raptor,1GB PC3200,Audigy 2

Michael,Roger the APP mode. I abandon (automatically) the MCP altitude as soon as I intercept the glideslope.Thanks,Gus White

Are you certainly it really is no longer following the G/S? What do you see that gives you this idea? What does it show on the pilot's flight display at this time? AT 400 RA the AFDS applies BIAS TRIM for landing so the nose will raise at this point and you will HEAR the trim doing it's thing. Leave it and watch what happens..[h4]Randy J. Smith[/h4]

Randy,At about 500 feet the aircraft is released from the APP G/S and begins to climb back to the altitude assigned by ATC "until established on the localizer." I noticed some letters popped up on the display - "GWS P" - I think. At any rate, at that point in my landing approach I must disengage the AP and land manually, which is not a problem as long as I have visual.Thanks,Gus White

>Randy,>>At about 500 feet the aircraft is released from the APP G/S>and begins to climb back to the altitude assigned by ATC>"until established on the localizer." I noticed some letters>popped up on the display - "GWS P" - I think. At any rate, at>that point in my landing approach I must disengage the AP and>land manually, which is not a problem as long as I have>visual.>>Thanks,>Gus WhiteIs it possible that you are touching the controls or possibly have noise coming from your controller which the Autopilot is interpreting as an input in pitch or roll, and disconnecting the approach? Might want to check calibration of your control device.

I had a similar problem and I couldn't for the life of me work out what was going wrong. However, I think I know what I may have been doing wrong. When I set up the autopilot for intercepting the glideslope, I also left the ALT hold button on to bring me down to the altitude given to me by ATC - 2,500ft. I seem to remember reading that the APP light will go out at some point when on the glideslope and I'm sure this was happening. What I think was happening was that when the light went out the ALT hold kicked back in sending the plane back up to 2,500ft. I think I need to either switch off the ALT hold , amend it to decision height, or to ground level height. I haven't tried this yet (I was at work when the idea came to me) but I'm going to try it out.

Makes sense, Victor. I'm going to give it a try tonight, but I don't understand why the APP light would go off and it would default back to the ALT hold altitude. I'm wondering if I have something in the FD or FMC that is creating this problem.This really isn't an issue unless you need the G/S all the way to the ground, then it becomes critical.Thanks,Gus

I tried my idea and it went a bit pear shaped! Not sure if mucking up my IFR route made it go wrong or not. Back to the drawing board!! :-walksmile

>Makes sense, Victor. I'm going to give it a try tonight, but>I don't understand why the APP light would go off and it would>default back to the ALT hold altitude. I'm wondering if I have>something in the FD or FMC that is creating this problem.>>This really isn't an issue unless you need the G/S all the way>to the ground, then it becomes critical.>>Thanks,>Gus The APP light is suppose to go out at G/S capture. The reason it goes back to ALT HOLD is most likely because you activated a CLIMB in Control Wheel Steering (CWS) and CWS captured the MISSED APPROACH ALTITUDE set on your MCP's altitude window and leveled off like it is suppose to ;-)[h4]Randy J. Smith[/h4]

The APP light is suppose to go out at G/S capture.>> The reason it goes back to ALT HOLD is most likely because>you activated a CLIMB in Control Wheel Steering (CWS) and CWS>captured the MISSED APPROACH ALTITUDE set on your MCP's>altitude window and leveled off like it is suppose to ;-)Randy's right - if you see CWS P in the flight mode annunciator, the sim thinks you grabbed the yoke.Do us a favor - be sure not to touch anything or (if you're using a USB yoke), disconnect it once you captured the localizer.

Timothy,I do see the CWS P in the flight mode annunciator. Is there a setting to change this situation. I tried landing without touching the stick (it is a USB Logitech joystick), but eventually had to turn off the AP and grab the stick to land. I did not disconnect the stick -- does the USB device create a problem? I have a MS Sidewider force feedback I can try.Thanks for your help,Gus

You need to recalibrate your joystick or if you have a registered version of FSUIPC, use it to filter.

George,I'll try the recalibration, and I do have a registered version of FSUIPC, so I can give that a try as well.Thanks,Gus

>Timothy,>>I do see the CWS P in the flight mode annunciator. Is there a>setting to change this situation. I tried landing without>touching the stick (it is a USB Logitech joystick), but>eventually had to turn off the AP and grab the stick to land.>I did not disconnect the stick -- does the USB device create a>problem? I have a MS Sidewider force feedback I can try.>>Thanks for your help,>Gus You need to disable force feed back because it's movements are causing reverions to CWS modes.[h4]Randy J. Smith[/h4]

Thanks everyone! Calibrating the joystick fixed the G/S problem. :-)Gus