Commercial Pilot License (CPL) 2026 – 400 Free Practice Questions to Pass the Exam

The use of two spark plugs per cylinder in the ignition system serves primarily for redundancy and improved safety. This design ensures that if one spark plug were to fail or malfunction, the other can still provide the necessary ignition for the fuel-air mixture in the cylinder. This dual arrangement enhances reliability in engine operation, particularly important in aviation where engine reliability is critical for safety. By having an additional spark plug, the likelihood of engine failure due to spark plug issues is minimized, which is essential for maintaining safe flight operations.

While increasing fuel efficiency, reducing wear on the engine, and higher power output are important aspects of engine performance, they are not the primary reasons for the presence of two spark plugs. Fuel efficiency may be affected by proper ignition; however, the main goal is to ensure that the engine operates safely and effectively under various conditions. The presence of dual spark plugs contributes more to the redundancy and reliability of the system rather than directly influencing efficiency or power output.