Where are most APUs located in modern jet transport aircraft?

Where are most APUs located in modern jet transport aircraft?

• A. In the tail cone of the fuselage.
• B. In the aft fuselage near the tail.
• C. In the nose gear bay.
• D. Under the cockpit floor.

Answer: (A)

APUs are normally located in the tail cone of the fuselage. This aft-location takes advantage of available space in the tail, keeps the APU’s exhaust away from the crew and forward cabin, and allows straightforward routing of bleed air, electrical, and other lines to the airplane’s systems. It also makes maintenance access easier and avoids encroaching on cargo or wing areas. Placing the APU in the nose gear bay or under the cockpit floor would create clearance and heat/exhaust issues, while a general aft fuselage location without the tail-cone designation wouldn’t optimize exhaust routing or access the way the tail cone does.

APUs are normally located in the tail cone of the fuselage. This aft-location takes advantage of available space in the tail, keeps the APU’s exhaust away from the crew and forward cabin, and allows straightforward routing of bleed air, electrical, and other lines to the airplane’s systems. It also makes maintenance access easier and avoids encroaching on cargo or wing areas. Placing the APU in the nose gear bay or under the cockpit floor would create clearance and heat/exhaust issues, while a general aft fuselage location without the tail-cone designation wouldn’t optimize exhaust routing or access the way the tail cone does.