If engine start bleed pressure reads 41 psi, is this within tolerance?

• A. Only with GMN
• B. Yes
• C. No
• D. Only at altitude

Answer: (C)

Engine start bleed pressure must stay within a narrow range, because the start air has to be strong enough to assist starting without over-pressurizing the system. A reading of 41 psi is outside the allowable upper limit of that range, so it’s not considered within tolerance. The tolerance is a fixed spec for normal operation, not something that only applies in GMN scenarios or at altitude. When you see a value like 41 psi, you’d verify the gauge accuracy, inspect the bleed air regulator and valves for proper operation, and recheck or consult maintenance to bring the reading back into the specified range.