By how much does the FADEC automatically increase N1 when N1 speed differences exceed the threshold?

By how much does the FADEC automatically increase N1 when N1 speed differences exceed the threshold?

• A. 15%
• B. 5%
• C. 10%
• D. 20%

Answer: (A)

When two engines are supposed to produce similar thrust, the FADEC watches the N1 speeds and looks for differences that are bigger than a safe threshold. If the gap is too large, the system corrects by forcing the slower engine to speed up by a fixed amount, quickly bringing the two N1 values back toward each other. In this setup, that corrective increment is 15%, so the FADEC raises the N1 of the lagging engine by 15% to restore balance and reduce the risk of asymmetric thrust. This quick, predefined adjustment helps maintain safety and smooth operation without requiring pilot input.

When two engines are supposed to produce similar thrust, the FADEC watches the N1 speeds and looks for differences that are bigger than a safe threshold. If the gap is too large, the system corrects by forcing the slower engine to speed up by a fixed amount, quickly bringing the two N1 values back toward each other. In this setup, that corrective increment is 15%, so the FADEC raises the N1 of the lagging engine by 15% to restore balance and reduce the risk of asymmetric thrust. This quick, predefined adjustment helps maintain safety and smooth operation without requiring pilot input.