What is the typical engine start sequence for a narrowbody and what checks are performed before starting?

• A. Ignition is not used during start.
• B. Select power source (ground power or APU), perform start sequence, engage ignition, monitor N2 spool, and verify no warnings; ensure parking brake is set and area is clear.
• C. Start by moving the engine start switch to the start position without selecting a power source.
• D. Engine start sequence is optional if a GPU is available.

Answer: (B)

Starting a narrowbody engine on the ground follows a practical sequence: first provide a reliable power source (external ground power or APU) to run the starter and supply electrical/bleed air as needed. With power available, initiate the start sequence and then engage the ignition to light the fuel-air mixture. As the engine spools up, monitor the N2 speed to ensure smooth acceleration toward idle and watch for any abnormal indications. Check for warnings or cautions and confirm there are none before advancing. Finally, ensure the parking brake is set and the area is clear of personnel and obstacles to prevent hazards during the start.

The other options miss essential parts of the procedure or state conditions that aren’t accurate, such as starting without power, skipping ignition, or implying a GPU makes the start optional.