Final answer:
The APU air intake is located on the lower section of the fuselage, while the APU exhaust is typically found at the rear of the aircraft. These placements ensure efficient operation and safety by avoiding debris and directing hot gases away from the plane's structure.
Step-by-step explanation:
The APU (Auxiliary Power Unit) air intake and the APU exhaust are critical components of an aircraft's auxiliary systems. The air intake is typically located on the lower section of the fuselage and is responsible for providing clean, uninterrupted air flow to the APU for its operation. On the other hand, the APU exhaust is generally found at the rear of the aircraft, sometimes at an upward angle, and is designed to safely expel the hot exhaust gases produced during the APU's operation.
The exact placement of these components can vary based on the aircraft's design, but the general principle is that the air intake must be positioned in such a way that it avoids ingesting ground debris and exhaust gases from the APU or the main engines. Meanwhile, the exhaust must be positioned to keep the hot gases away from any sensitive aircraft structures and to minimize the risk of fire.