What are the engine start limitations using external power for engine operations?

• A. 15 seconds on, 30 seconds off
• B. 25 seconds on, 30 seconds off
• C. 30 seconds on, 40 seconds off
• D. 25 seconds on, 30 minutes off

Answer: (B)

The correct answer reflects the procedure established to ensure the proper functioning and longevity of the engine during start attempts using external power. Using external power helps facilitate starting the engine without draining the aircraft's internal battery.

In this context, the limitation for external power engine starts is typically designed around the need to prevent overheating or damage to the starter and the associated electrical systems. By limiting the engine start attempt to 25 seconds on, followed by a 30 seconds off period, the procedure allows for adequate cooling and recovery time for the system before another start attempt is made. This is particularly important in training and operational environments where the engine must be reliable and ready for immediate use after a start attempt.

Understanding this limitation helps students not only to follow NATOPS guidelines but also to appreciate the operational safety measures that safeguard the aircraft and its components during engine start procedures.