There is no chance to build a back-taxi routes in MSFS.
For example, runway has only one taxiway connected in the middle of the runway.
For take-off the AI aircraft need to go to runway, get taxiing on runway to the end, make a U-turn and take-off.
All possible routes can be builded but in fact, in the sim, AI stops on the holdshort point “forever” with no any chance for take-off.
AI debug status is “Taxi” but no any moves.
The same for landing - staying on the holdshort the AI aircraft blocks exit from the runway for all arriving AI or user aircraft.
Building few HOLDSHORT points to freeing some space for taxiing has no any effect.
How to build the back-taxi route?
So, I did some more testing and finally built the working taxiing path except one " BUT ".
First of all, one trick which can make airport testing simpler and faster.
Start your airport and switch on AI control Checklist, AI control ATC, AI control aircraft.
You will have an immediate start, pushback and taxiing for take-off using the same algorithm as AI aircraft.
In my case, my copilot stopped taxiing few taxipath segments before HOLDSHORT. Hmm… Why?
I took the aircraft control (AI control aircraft - OFF) and kept taxiing.
Once I stopped on the HOLDSHORT, I switch AI control aircraft back.
AI immediately contact tower, got clearance for take off and continued taxiing.
The working path (at least for me) looks like that:
And U-turn:
It was quite fun to see how AI increased the speed on the runway for taxiing.
Made good U-turn and take-off.
Then I repeated the same “AI control aircraft” scenery for landing and it was just perfect!
Landing, ATC, taxiing, turns, parking - everything with no any issues.
So, now we narrow the issue with the HOLDSHORT.
What prevent AI aircraft to approach the HOLDSHORT point? Why couple path segments blocks the taxiing?
P.S. I built three HOLDSHORTS to make AI aircraft wait outside of taxiing path. Later on will mark them “NO DRAW” and put the painted HOLDSHORT line on the place.