Autopilot default descending FPM.....

[vomacka]

When I use the autopilot to descend from 25,000FT, I have -1800FPM decent dialed in (VS window), but it always descends at -800 FPM. This happens in all the planes (including default). It seems to descend at a default rate of -800 FPM, instead of the -1800 FPM that is shown in the autopilot VS window.

 

Is there anyway to adjust this default setting from -800 to -1800 FPM? The autopilot works correctly on climb. (+1800)

 

Scott

CNJC-IPMS

 

P.S.

YES, I know I can adjust the "dial" on the autopilot, but I would like to change the default setting to -1800 instead to fix the problem.

[CptCaveman]

This is intended behaviour when you change your altitude setting on the FDC from level flight. You can control it manually.

 

 

Aircraft CFG file> autopilot section.

 

IIRC its the "default vertical speed" setting. Simply change it to zero and it will no longer dial in aything on altitude changes. Or change it to whatever value you like as your "default".

[mrzippy]

Are you manually turning the VS knob to set -1800 feet or does that come up automatically? Default setting in the [Autopilot] section should be 1800. To get it to descend at -1800 I usually click the VS knob once to -1900 then click back to -1800 and the AP does the rest.

[vomacka]

In all of my airliners (Including default) I have "default_vertical_speed=1800.000" set in the config "autopilot" section. It would seem that this setting is ignored during descent, and defaults to -800fpm. Let me try changing this value to 1900 and see what happens.

 

Scott

CNJC-IPMS

 

Just tried it and no change, still descends at -800fpm.

[mrzippy]

In all of my airliners (Including default) I have "default_vertical_speed=1800.000" set in the config "autopilot" section. It would seem that this setting is ignored during descent, and defaults to -800fpm. Let me try changing this value to 1900 and see what happens.

 

Scott

CNJC-IPMS

 

Don't change that value in the aircraft.cfg! Just click the VS knob on the AP in the cockpit to get it to happen.

[RickG]

I do the exact same thing as zippy does--very easy, and simple.

[dspaulding]

This is a bit off topic, but 800fpm is a good starting point for changing altitude. IRL most autopilots are very aggressive to achieve target rates. It is good practice to start with 1000fpm or less, wait three seconds, then dial desired rate. IRL you can easily float a flight attendant or pax with the sign off which could result in injury. That therefore leads to the chief pilots office, which is not good.

[mqytn]

Just wondering if you are using a FMC that is over riding the default autopilot?