Question

Explain the general concept behind rotary aircraft structure and construction methods.
And describe the airworthiness requirements applicable to the design and construction of a typical rotary aircraft fuselage and system such as phlone, fule storage and symmetry

Answer 1

A rotary aircraft also called as helicopter has many weight-controlled horizontal rotors to advance lift. If only one main rotor is utilised, it is required to use a medium to oppose torque. If many rotors are used, torque is removed by rotating each main rotor in reverse directions.

The main rotor and rotor head are indistinguishable in flight mechanics but vary in engineering or design. The drive-train, power plant,  hydraulic flight control, transmission, and other systems all work in cohesion. The rotor head is completely asserting and is rotated by torque through the engines and the drive train through main gearbox. The flight modulator and hydraulic servos transfer motion to the rotor blades. The basic parts of the head are the hub and swashplate. The hub is single, made of titanium and rests over the rotor mast. Connecting parts are the blade fold components, sleeve and spindles, vibration absorbers. The swashplate has a rotating disc, stable portion with a scissors and sleeve distinguished by a bearing. The swashplate is allowed to slip on the main rotor vertical driveshaft and installs over the main transmission. The entire system can tilt in a random direction based on the movement of the flight controls.  

The foremost landing gear system has left and right one-wheel landing gear system. Each main landing gear assembly is consists of a wheel, tire, shock strut, axle, drag beam and wheel brake. The left main landing gear assembly also consists of a weight-on-wheels identifying switch. The landing gear assists the helicopter when on the runway and shields the helicopter from shock while descending.

The main rotor pylon (phlone) is connected to the upper cabin and transformation section. The front part is constructed of a removable platform, sliding control, and air inlet fairings. The middle part includes the environmental control system ingress, left and right oil cooler ingress, auxiliary power system. The rear section consists of the fire bottle ingress and rear fairing. The tail rotor pylon is a foldable part at the rear part of the helicopter. The pylon is sustained to the tail cone part. It bears the horizontal stabilator, intermediate gearbox and tail gearbox.