Topic: Module 3 LOB 1
Rotorcraft Structures and Flight Controls
Rotary-wing aircraft possess unique capabilities enabling them to support diverse operations throughout the aviation spectrum. Rotorcraft are operated by numerous organizations, they are utilized by emergency medical transportation, aerial firefighting service companies, law enforcement, the military and many more. The main advantage of a rotorcraft is its ability to hover and make approaches to landing in confined spaces away from an airport. In order for rotorcraft to accomplish this, they must be engineered with durability and maneuverability in mind. A rotorcraft’s fuselage or structure must be strong and light weight while its flight controls agile and reliable. The type of rotor system designed is very important as well. There are two types commonly found on rotary-wing aircraft today. They are a fully articulated or semi-rigid under slung see saw type rotor system. Both have their own advantages and dis-advantages over the other. The fully articulated rotor system is complex by design, it has excellent control authority in the pitch and roll axis. It also typically has more than two rotor blades which reduces sound signature and increases control authority in the pitch and roll axis controlled by the cyclic due to its solidity ratio. The semi-rigid rotor system is a much simpler design thus, it cost significantly less to maintain but control authority in the pitch and roll axis is sluggish compared to the fully articulated rotor system due to its lower solidity ratio. Rotorcraft structures normally consist of three sections; the forward, intermediate, and tail boom sections. Each of these sections is composed of different materials used to strengthen the frame, eliminate excessive weight, and create flexibility in the structure where required. The forward section of a rotorcraft consist of the nose, cockpit, and cabin areas of the aircraft, most designs are
References: Accessed on 03 February 2012 from http://aviationglossary.com/monocoque-fuselage-design/ Accessed on 03 February 2012 from http://www.tpub.com/air/10-4.htm