What is the standard engine start sequence for a modern narrowbody engine?

• A. Confirm power source (APU/ground power), initiate start, monitor parameters, verify stable idle before advancing thrust.
• B. Power the engine directly from the battery and go to full thrust immediately.
• C. Start without external power and wait five minutes.
• D. Enable automatic start during taxi in.

Answer: (A)

Starting a modern narrowbody engine is a controlled, multi-step process that relies on providing electrical and pneumatic power from the ground or APU to drive the start system, then carefully monitoring the engine until it light-offs and reaches a stable idle. First, external power (APU or ground power) supplies the aircraft systems and, if required, bleed air to the pneumatic starter. With the start control engaged and ignition armed, fuel is introduced and the starter spins the N2 spool. Light-off occurs as the combustor ignites, and the engine becomes self-sustaining once the fuel-air mixture is stable and the oil pressure rises. After light-off, you monitor the parameters—ITT or EGT within limits, stable N1/N2 speeds, and adequate oil pressure—and confirm the engine is operating at a normal idle before gradually advancing to higher power as needed. This approach avoids unsafe light-off, prevents compressor stall or surges, and ensures a clean transition to a safe takeoff thrust. The other options skip essential steps or propose unsafe or nonstandard methods, so they don’t reflect proper procedure.