What is the minimum start pressure required for engine systems?

• A. 28 psi
• B. 30 psi
• C. 32 psi
• D. 34 psi

Answer: (C)

Starting an engine with the air-start system requires enough pressure to drive the starter and spin the engine to a speed where it can light off and sustain itself. The minimum pressure value in this context is the lowest pressure at which that starter can reliably deliver the needed torque to overcome engine friction and any start-up losses. For this aircraft’s engine systems, that threshold is 32 psi. Pressures below that, like 28 psi or 30 psi, aren’t sufficient for a reliable start, while a higher pressure such as 34 psi would still work but isn’t the minimum. So 32 psi represents the required lower limit to ensure a successful start.