What are the three sections of the transmission?

• A. Gearbox, RGB, AGB
• B. Upper case, RGB, AGB
• C. Upper case, lower case, AGB
• D. Mast, RGB, AGB

Answer: (B)

The correct answer identifies the three main components of the helicopter's transmission system, which are pivotal in delivering power from the engine to the rotors. In the context of the TH-73, the terms "Upper case," "RGB" (Reduction Gearbox), and "AGB" (Accessory Gearbox) accurately represent sections of the transmission.

The upper case refers to the main section that houses the primary components of the transmission and is critical for maintaining the structural integrity of these systems. The RGB serves to reduce the high rotational speeds from the engine to appropriate speeds for rotor operation, which is essential for efficient power transmission. The AGB transfers power to various accessories such as the hydraulic pumps and generators, playing a vital role in the overall functionality of the helicopter.

This combination is essential for the effective operation of the helicopter's flight systems, making it crucial to understand these components and their interactions. Understanding the roles of each section allows for better insight into how they collaboratively ensure the helicopter's performance and reliability in flight.