B1900C Autopilot Question

[GAJ52 54]

There appears to be two Altitude autopilot modes ALT and ALT SEL, I was flying at 7000 ft with ALT SEL selected and the autopilt engaged, I then selected ALT to maintain 7000 while re-selecting a higher altitude for a later climb. The aircraft very slowly at about 50 to 100 fpm continued to descend. The QNH remained the same so it wasn't pressure related.I have the latest service update, has anyone else found this problemGlen

[Guest tmetzinger]

>There appears to be two Altitude autopilot modes ALT and ALT>SEL, I was flying at 7000 ft with ALT SEL selected and the>autopilt engaged, I then selected ALT to maintain 7000 while>re-selecting a higher altitude for a later climb. The>aircraft very slowly at about 50 to 100 fpm continued to>descend. The QNH remained the same so it wasn't pressure>related.>>I have the latest service update, has anyone else found this>problem>>GlenPressing ALT will hold your current altitude and should reset the altitude alerter to the current altitude.ALT SEL _OR_ changing the altitude in the altitude alerter initiates a climb/descent to the selected altitude at 100FPM.This is NOT like the 737 where ALT HOLD is completly independent of MCP altitude.Remember that the Express line uses the default FS9 autopilot and it's somewhat screwy logic.

[strider 0]

While we are on the subject of the AP, after reading the above reply (which was going to be my first question!) I'm still unclear on what the AP "CLIMB" and "DSC" buttons do. A short addition to the manual, regarding the AP, might be useful when you do an update of it. Thank you. Vic

[Guest tmetzinger]

Climb and DSC set the VS to 1000 fpm, either up or down, depending.

[strider 0]

Thanks, Tim. Vic