Which statement is true about Engine Start 1 & 2 crank limits when comparing ground and flight operations?

Which statement is true about Engine Start 1 & 2 crank limits when comparing ground and flight operations?

• A. Ground limit is 90 sec ON; Flight limit is 120 sec ON
• B. Ground limit is 120 sec ON; Flight limit is 90 sec ON
• C. Ground limit and Flight limit are the same
• D. Ground limit is 60 sec ON; Flight limit is 120 sec ON

Answer: (A)

Starting limits reflect how the engine is cooled and how the system protects its components during a crank. On the ground, there’s little airflow cooling the engine, so a prolonged start can overheat the starter and cause heat damage. To prevent that, the ground crank limit is set at 90 seconds. In flight, ram air from the airstream provides cooling, allowing a longer continuous crank during a start attempt, so the flight limit is extended to 120 seconds. That combination—90 seconds on the ground, 120 seconds in the air—best matches the engine’s protection and cooling realities, making the statement with those limits the correct one.

Starting limits reflect how the engine is cooled and how the system protects its components during a crank. On the ground, there’s little airflow cooling the engine, so a prolonged start can overheat the starter and cause heat damage. To prevent that, the ground crank limit is set at 90 seconds. In flight, ram air from the airstream provides cooling, allowing a longer continuous crank during a start attempt, so the flight limit is extended to 120 seconds. That combination—90 seconds on the ground, 120 seconds in the air—best matches the engine’s protection and cooling realities, making the statement with those limits the correct one.