Hello Warren,
I have not been able to reproduce the problem with the aircraft, this is one of the few that start with the door open, using the B key will close the door before starting the aircraft. On using the B key to stop the engine the door will reopen, after the prop has stopped. You can override the operating using the H key manually, or if there is a trigger on the track set to operate the doors (trigger setting 1).
In the script I use a boolean setting: bool door_position = true; or false to define the state of the doors. Using the B key I did not redefine the state in that part of the script when the door closed, it seemed to work without it, but perhaps I need to re-look at that if it is causing a random malfunction. Check if you did have a track trigger wrongly set or you accidentally pressed the H key.
Ian