It's basically a crude, low polygon aircraft (7572 mesh triangles/8 draw calls), no LODs and a pilot painted on the glass. The.air file seems quite truncated too.
The aircraft is out of balance when in motion on the ground. When it moves forward from the parking spot the nose gear raises and then lowers itself into the concrete, repeating this each time the brakes are applied.
This is the attitude on leaving the parking spot:

The aircraft did complete my IFR circuit, but again the braking on landing was pretty horrific:

This may not be the cause of the problems being experienced, but you might just want to check that your frame rate is in excess of 24fps (CTRL ZZ)). If the frame rate is very low, it can exacerbate faults to the extent that the aircraft just won't perform properly, or sometimes just crash.
I could spend some time trying to smooth the imbalance out, but if the object of the exercise is to learn how to set up AI aircraft, I would be inclined to pick an aircraft that we know works fine. Have a search through the MAIW Download Hangar and perhaps try something different in your flight plan.
John