Under normal operation, which hydraulic system(s) power the main rotor servo actuators?

• A. No.1 hydraulic system
• B. No.2 hydraulic system
• C. No.1 and No.2 hydraulic systems
• D. 28VDC

Answer: (C)

The main rotor servo actuators of the TH-73A are powered under normal operation by both the No.1 and No.2 hydraulic systems. This dual system configuration is designed for redundancy and enhanced reliability. In the event of a failure in one hydraulic system, the other can still provide adequate pressure and flow to ensure proper operation of the main rotor actuators.

This design ultimately enhances flight safety by creating a backup mechanism. The simultaneous use of both hydraulic systems allows for a more consistent performance under various flight conditions and reduces the risk of loss of control should one system encounter an issue. Hence, using both the No.1 and No.2 hydraulic systems is crucial for maintaining safe and effective helicopter operation.