Final answer:
The minimum distance back from the AIP that non-crushable objects must be depends on regulations and the requirements of the airfield. It is generally determined by the radius of the AIP and the clearance needed for safe aircraft operation.
Step-by-step explanation:
The minimum distance back from the AIP that non-crushable objects must be depends on the specific requirements and regulations of the airfield. However, in general, the minimum distance is determined by the radius of the Aircraft Imaginary Point (AIP) and the clearance required for the safe operation of aircraft. The AIP is a point on the ground directly below the center of gravity of the aircraft.
For example, let's consider a hypothetical scenario where the AIP has a radius of 100 feet. In this case, non-crushable objects should be located at a minimum distance of 100 feet away from the AIP to ensure that there is enough clearance for the aircraft to taxi, take off, and land safely.
It is important to note that these regulations may vary depending on factors such as the size of the aircraft, the type of airfield, and local aviation authorities' guidelines. Professionals, such as airfield engineering experts or regulatory bodies like the Federal Aviation Administration (FAA), are responsible for determining and enforcing these regulations.