With thrust levers in CRZ or CLB, the engines will sync to N1 or N2 when they are within _______.

The correct answer is 5%. This percentage refers to the threshold within which the thrust levers will synchronize the engine thrust values, specifically focusing on N1 or N2, which are the key parameters for engine performance. In cruise (CRZ) or climb (CLB) phases, maintaining balanced thrust between engines is critical for operational efficiency and safety.

When the thrust lever settings are within 5% of each other, the automated system can engage to ensure that both engines are producing similar thrust levels. This synchronization helps to optimize fuel efficiency and reduce engine strain, which can be particularly important during phases of flight where maintaining a steady climb or cruise is necessary.

If the engines are out of this defined range, the system will not engage, as it generally is designed to operate most efficiently when there is a close match in thrust output. This operational detail is vital for understanding aircraft performance management and ensuring smooth, safe flight operations.