When parking a vehicle with a manual transmission in close proximity to an aircraft, what gear should it be left in?

When parking a vehicle with a manual transmission in close proximity to an aircraft, it is recommended to leave the vehicle in reverse gear. This is because positioning the vehicle in reverse can help prevent it from rolling away. In the event that the parking brake fails or if the surface is sloped, having the vehicle in reverse provides an additional layer of security due to the way the gear engages with the transmission, effectively locking the wheels in place against the natural rolling motion.

While other gears like first or second gear can also prevent rollback, reverse is often flagged as the preferred choice due to its effectiveness in keeping the vehicle stationary in a backward-facing position, which can be particularly important near aircraft where safety is a priority. Neutral, on the other hand, does not provide any resistance, leaving the vehicle susceptible to rolling if the brake fails.