SIFT Army Aviation Information Practice Test

What is a common feature of helicopters with multiple rotor systems?

1. They utilize a single transmission for both rotors.

2. They have independent throttle controls for each rotor.

3. They can have either coaxial rotors or tandem configurations.

4. They do not have any redundancy in control systems.

The correct answer is: They can have either coaxial rotors or tandem configurations.

In helicopters equipped with multiple rotor systems, a common feature is indeed that they can have either coaxial rotors or tandem configurations. Coaxial rotor systems consist of two rotors mounted one above the other on the same axis, allowing more efficient use of space and improved lift capabilities. Tandem rotor helicopters, on the other hand, feature two rotors mounted in line with each other, which helps balance torque and provides stability during flight. The design of these rotor systems maximizes aerodynamic efficiency and allows for better lift-to-drag ratios, which is critical for the performance of helicopters, particularly in challenging conditions. This characteristic is foundational to the advantages offered by dual rotor configurations in terms of payload capacity, stability, and maneuverability. The other options describe features that are not commonly associated with all helicopters that utilize multiple rotor systems. For example, while some helicopters with multiple rotors may use independent throttle controls, this is not a universal characteristic across all models. Similarly, most helicopters utilize separate transmissions for each rotor to ensure effective control and performance. Lastly, redundancy in control systems is crucial for safety in aviation, and most helicopters, including those with multiple rotor systems, typically incorporate redundancy to enhance reliability.