APU (Auxiliary Power Unit)
🛩️ What is an APU in an Aircraft?
-The APU (Auxiliary Power Unit) is a small engine usually located at the tail of the aircraft. It’s not used to fly the plane, but it’s super important when the aircraft is on the ground!
👀 What Does the APU Do?
⚡ Gives Electricity
It powers the cabin lights, cockpit displays, and other systems when the main engines are off.
🌬️ Blows Compressed Air
It helps start the main engines and run the air conditioning while on the ground.
🛠️ Works Like a Mini Jet Engine
It takes in air, burns fuel, creates energy, and sends hot air out the exhaust.
📸 What’s in the Picture?
🔹 Top part shows where the APU is placed — in the back of the plane, in a fire-protected area.
🔹 Bottom part shows its parts:
-Air intake (takes air in)
-Igniter (starts it up)
-Compressor & Power section (creates energy)
- Exhaust (hot air out)
- Generator & Gearbox (gives electricity)
💡 So, even when the engines are off, the APU keeps the plane “alive” — powering everything from lights to AC.
It’s small, but it does a BIG job! 💪
