Autopilot - unable to preselect.

eker

msfs2020
AP disengaged.
Hitting hdg select button - AP instantly engages, bypassing activate button (flight controls moves). Disengage - AP goes to default rol mode.
I normally preselect modes on ground, and when airborne I hit engage button. Now the engage button seems to have no function - except disengage.
.
Edit:
The same goes for vs preselect. Preselect vs on ground (example 700 ft/min) the AP instantly engage. Disengage and preselect is lost. What is worse, the trim starts to move, and you must remember to adjust trim again.

I have checked key bindings for conflict.

thanks
øystein.

Bert Pieke

This early version of the KAP140 autopilot indeed engages the autopilot when you select any mode.. It does not support FD (Flight Director) operation.. You will need to adjust to its quirky operation.. I am also finding it difficult to get used to.

eker

Thanks.
The engage button on KAP140 is really a troublemaker. Do not touch....
My new procedure:
Only select desired alt on ground. Scroll knob.
Lining up on runway - Set bug on rwy heading.
After TO - hit AP hdg button. AP instantly engage.
AP pitch mode is now set to actual pitch or vs . I am not sure which- but now you can adjust vs with up/down buttons.

Bert Pieke

@eker said in Autopilot - unable to preselect.:

Thanks.
The engage button on KAP140 is really a troublemaker. Do not touch....
My new procedure:
Only select desired alt on ground. Scroll knob.
Lining up on runway - Set bug on rwy heading.
After TO - hit AP hdg button. AP instantly engage.
AP pitch mode is now set to actual pitch or vs . I am not sure which- but now you can adjust vs with up/down buttons.

Kind of... For me, it starts in PIT mode which is not what the RW unit does.. It starts up in VS mode. That matters because only VS mode can be adjusted via the up/down buttons..

MiRexer

Here's the workflow I've come up with. Set altitude for the autopilot on the ground. After takeoff get the plane trimmed for a normal climb then engage the autopilot and heading mode. It's now in pitch and Alt Arm mode and I can use the CWS button on the yoke to adjust the pitch attitude. Once it captures the target altitude then I can change the target altitude and hit alt to put it in VS and Alt Arm mode and use the up down to set the climb/descent rate.

I have sometimes been able to get it back into a pitch mode but I haven't yet figured out the magic combination to do so.

Here's the KAP140 manual - it does talk about a CWS button in it: https://www.bendixking.com/content/dam/bendixking/en/documents/document-lists/downloads-and-manuals/006-18034-0000-KAP-140-Pilots-Guide.pdf

Bert Pieke

A better way, I believe, is to get rid of Pitch mode entirely (as in the real unit).

A brute force hack is adding this to an interior model xml file, in an Update section:

(A:AUTOPILOT ATTITUDE HOLD, bool) if{ (>K:AP_PANEL_VS_SET) }

Hopefully Nick @Black-Square has a better way..