What is the name of the component that controls the APU start and operation?

What is the name of the component that controls the APU start and operation?

• A. APU Start Switch
• B. Electronic control box (ECB)
• C. APU Control Unit
• D. Control Module

Answer: (B)

The Electronic Control Box (ECB) is the brain of the APU, handling start sequencing, ignition, fuel valve control, and the transition to running. It receives the start command from the APU Start Switch and continuously monitors critical parameters such as N2 speed, EGT, and oil pressure, auto‑shutting the APU down or preventing a start if anything unsafe is detected. This supervisory role—coordinating start, speed ramp, and fault protection—is why the ECB is the correct name for the component that controls APU start and operation. The APU Start Switch is just the manual command, while the other terms aren’t the standard designation for the APU’s controlling unit in Airbus documentation.

The Electronic Control Box (ECB) is the brain of the APU, handling start sequencing, ignition, fuel valve control, and the transition to running. It receives the start command from the APU Start Switch and continuously monitors critical parameters such as N2 speed, EGT, and oil pressure, auto‑shutting the APU down or preventing a start if anything unsafe is detected. This supervisory role—coordinating start, speed ramp, and fault protection—is why the ECB is the correct name for the component that controls APU start and operation. The APU Start Switch is just the manual command, while the other terms aren’t the standard designation for the APU’s controlling unit in Airbus documentation.