N2 Sync can be activated within what percent?

N2 Sync can be activated within what percent?

• A. 1.0%
• B. 1.5%
• C. 2.0%
• D. 2.5%

Answer: (D)

N2 Sync is about keeping the two engine high‑pressure spools running at the same speed. When you activate it, the engine control automatically trims the engines so their N2 readings come into close agreement, reducing differences that can cause asymmetric thrust, yaw, or vibration. For the CRJ‑550’s engine system, the synchronization is designed to work and be maintained when the N2 difference between the engines is within about 2.5 percent. That means once the two N2 speeds are within roughly two and a half percent of each other, the system can hold them in that aligned state, improving smoothness and stability. That’s why 2.5 percent is the correct specification. Tighter tolerances would be harder to guarantee in routine operations, and a looser tolerance isn’t the intended activation criterion.

N2 Sync is about keeping the two engine high‑pressure spools running at the same speed. When you activate it, the engine control automatically trims the engines so their N2 readings come into close agreement, reducing differences that can cause asymmetric thrust, yaw, or vibration.

For the CRJ‑550’s engine system, the synchronization is designed to work and be maintained when the N2 difference between the engines is within about 2.5 percent. That means once the two N2 speeds are within roughly two and a half percent of each other, the system can hold them in that aligned state, improving smoothness and stability.

That’s why 2.5 percent is the correct specification. Tighter tolerances would be harder to guarantee in routine operations, and a looser tolerance isn’t the intended activation criterion.