This was really strange it never happen in my flightsim history and i don't know if it's NGX related.I was park at PHNL gate before engine start and the aircraft start to move alone without any input once up to the nearby hills it stop and descent form the hill then i was back to normal and able to use my input.The only way i could stop it was pause and use slew but in normal it was going only in one direction i start to use pedals and yoke to see of any change but nothing.It can be only onetime or a noise from hardware even if controls where uncheck in FSX, i just want to write as found really strange phenomen.

Apply handbrake. Gears in neutral!

The brake melt

It sounds like you to Need to have the parking brake set before you open your flight. If you areusing a presaved flight, try saving the flight whith the park brake set. If not, try setting the park brake in your your current flight while parked at the gate. Exit the flight. Open the flight again and see if the brakes are set now. Hope this helps.Jason Chandler

Runaway tug

My guess would be wayward joystick logic.