How is the main transmission mounted in a helicopter?

• A. On a single support beam
• B. By four vertical load struts
• C. With horizontal braces
• D. Using flexible mounts

Answer: (B)

The main transmission in a helicopter is typically mounted by four vertical load struts. This configuration is crucial because it provides the necessary structural integrity and stability required to support the heavy and complex components of the helicopter's rotor system. The vertical load struts help distribute the forces that arise during flight maneuvers and engine operation, ensuring that the transmission remains securely attached to the airframe while minimizing vibrations that could affect performance or induce wear over time.

The use of four vertical load struts creates a robust support system that can handle dynamic loads and provide effective alignment for the rotor shafts. This design allows for both strength and rigidity, which are essential for maintaining the helicopter's performance and safety. Proper mounting of the main transmission is vital to ensure smooth operation and prevent mechanical failure.

In contrast, other mounting methods like a single support beam, horizontal braces, or flexible mounts would not offer the same level of support and stability needed for the challenges faced during helicopter flight. Each of these alternatives could lead to inadequate load distribution or insufficient damping of vibrations, which are critical aspects of helicopter design and operation.