When engines are running and bleeds configured for takeoff, N1 target values must correspond to thrust chart data within?

• A. Yes, within +/-1%
• B. No, there is no requirement
• C. Only at sea level
• D. Only during high altitude operations

Answer: (A)

When bleeds are configured for takeoff, the N1 target values are taken from the published thrust charts and are used to set the expected engine thrust for the given weight, altitude, temperature, and bleed configuration. The N1 shown as the target should match the chart value within a small tolerance to accommodate minor variations in engine performance, sensor readings, and airframe/engine differences. A tolerance of plus or minus one percent is standard because it keeps the engines producing the intended thrust without being too strict, which could lead to unnecessary adjustments or performance shortfalls. This requirement applies across the operating envelope, not just at sea level or at high altitude.