Path > visibility : On the diagram the rotating blade pitch control is indicated by the letter . ?

Question 38-1 : D a b c

What is a typical characteristic of a fully articulated rotor system ?

Question 38-2 : The blades are free to flap drag and feather independently of one another the rotor head has flapping hinges only the blades have hinges for all movements the rotor head only has elastomeric hinges for all movements of the blades

Which of the following statements with respect to the rotor brake is correct ?

Question 38-3 : The rotor brake is nearly always implemented as a disc brake the rotor brake is nearly always implemented as a drum brake the rotor brake always slows down the drive shaft between the engine s and the main gear box a hydraulically actuated rotor brake is connected to the same hydraulic system as the flight controls in order to ensure the necessary reliability

A rotor is fully articulated when ?

Question 38-4 : The blades each have the possibility to flap drag and feather separately the rotor head has hinges for flapping as well as dragging the blades have been mounted flexibly with regard to flapping and dragging the rotor has more than two blades that have separate flapping and feathering hinges

The chord length of the blades of a ducted tail rotor fenestron is ?

Question 38-5 : Smaller than that of a classic tail rotor the same as that of a classic tail rotor greater than that of a classic tail rotor depends on the type of material used

An elastomeric bearing flapping hinge in the rotor head ?

Question 38-6 : Contributes to a reduced maintenance effort allows larger blade flapping angles allows for larger forward speeds is utilised to absorb the loads on the rotor blades arising from vertical gusts

What are elastomeric bearing hinges in a rotor head ?

Question 38-7 : Flexible sections accomplishing the functions of flapping dragging and feathering hinges self lubricating hinges bending plastic parts rubber flapping and dragging hinges

Intermediate or angle gearboxes are used to ?

Question 38-8 : Change the direction and sometimes the speed of the tail rotor drive change the direction of the tail rotor drive only change the speed of the tail rotor drive only mount the tail rotor

To engage the main rotor drive prior to flight on a helicopter fitted with a ?

Question 38-9 : Smoothly accelerate the engine with rotor brake selected off accelerate the engine above rotor speed decelerate the engine then accelerate again until engine and rotor speeds are matched de select the free wheel and engage drive accelerate the engine until engine and rotor speed are equal then engage the clutch using either a mechanical lever or an electrical switch

The tail rotor gearbox changes direction of drive ?

Question 38-10 : Through 90° reduces rotational speed and provides facilities for tail rotor control through minus 90° and increases rotational speed and increases rotational speed and provides facilities for tail rotor control maintaining a constant speed

The purpose of a clutch in a helicopter transmission system is to ?

Question 38-11 : Permit the engine to be started with a low inertial loading permit the rotor to rotate freely during autorotation prevent the rotor turning in the wind when parked on the ground disengage the tail rotor drive in the event of a malfunction

Rotational drive from the gearbox to the rotorhead is transmitted by the ?

Question 38-12 : Main drive shaft scissors swashplate assembly pitch change arms

Intermediate or angle gearboxes are used to ?

Question 38-13 : Change the direction and speed of the tail rotor drive change the direction only of the tail rotor drive change the speed only of the tail rotor drive allow the incorporation of autopilot inputs into the tail rotor

In a free turbine helicopter installation ?

Question 38-14 : There is no need for a clutch between the engine and the transmission a free wheel is required between the compressor and the turbine the main rotor drive and the compressor are on a common shaft there must be a clutch between the engine and transmission

Helicopters which utilise a ''v' belt to transmit the drive from the engine to ?

Question 38-15 : A manual clutch an automatic system to ensure belt tension remains constant irrespective of temperature a means by which the engineer can set the belt tension an automatic clutch

Freewheel units between engine and main rotor gearbox are in most cases ?

Question 38-16 : The main rotor gearbox lubrication system the engine lubrication system an independent lubrication system driven by the main rotor gearbox an independent system driven by either the engine or an electrically driven pump

For a free power turbine engine ?

Question 38-17 : The turbine driving the main rotor transmission is mechanically independent from the gas generator the compressor driving the main transmission is mechanically independent from the power turbine the gas generator is free to run at a constant speed while the power turbine changes speed in response to changes in drag on the main rotor blades pilot control of the engine is limited to the selection of off ground idle and flight leaving the engine to automatically respond to rotor demands

Clutches are located in the drive between the engine and the main transmission ?

Question 38-18 : Helicopters with piston or direct drive gas turbine engines all helicopters helicopters fitted with piston engines only helicopters with free power turbine engines only

A tail rotor drive shaft running between two engines should be ?

Question 38-19 : Protected by a firewall mounted to allow for expansion mounted on its own bearing hangers the first being directly behind the main rotor gearbox protected by the engine fire extinguishing system

What is the purpose of the freewheel unit in the rotor drive system ?

Question 38-20 : To disconnect the failed engine from the main and tail rotor drive to enable the rotor to rotate freely for autorotation to be able to start the engine s without starting to turn the rotor to be able to disconnect the main rotor from the drive system when the engine fails

Does the freewheel unit is necessary for helicopter with free turbine engine ?

Question 38-21 : No not with new generation engines but only for multi engined helicopters no

A snatch engagement of a freewheel unit ?

Question 38-22 : May result in the shearing of the engine drive shaft is normal engagement is absorbed by flexible couplings on the engine drive shaft will cause the freewheel to ratchet until the pilot recovers the situation

A mercury clutch ?

Question 38-23 : Utilises the weight of the mercury to provide the centrifugal force to act on the clutch shoes is not used in helicopters due to the danger of mercury contamination of aluminium uses the liquid mercury as a hydraulic fluid is not used in helicopters due to the high weight of mercury

The input and output speeds of an intermediate gearbox ?

Question 38-24 : Differ to counter the effects of vibration differ to establish the speed for the tail rotor are the same are variable to provide varying thrust from the tail rotor to counteract torque loads from the main rotor system

Tail rotors rotate ?

Question 38-25 : At a greater speed than the main rotor and at a different speed than the drive shaft and intermediate gearbox at the same speed as the shafts and gear boxes at a greater speed than the main rotor and the tail rotor drive shafts at a lower speed than the main rotor

Why are one or more flexible couplings usually incorporated in the tail rotor ?

Question 38-26 : To absorb the angular differences arising from bending of the tail to absorb quick power changes to prevent vibrations to prevent torsion of the shafts

Metal tail rotor drive shafts are normally manufactured from ?

Question 38-27 : Aluminium or steel tubing aluminium tubing only steel bar titanium and steel tubing

On the diagram the flapping hinge is indicated by number ?

Question 38-28 : 1 2 3 4

When using a strobe type tracking and balancing system on a fully articulated ?

Question 38-29 : The blade damper on the subject blade is not functioning correctly the blade rigging is out of adjustment the pitch change rod is not correctly adjusted the blade trim tabs are not correctly adjusted

What indication will be available to the pilot of wear in either tail rotor ?

Question 38-30 : Vibration through the tail rotor/yaw pedals stiffness in the tail rotor controls instability in pitch control loud noise from the tail rotor

On the diagram the lead/lag hinge is indicated by number . 2429 ?

Question 38-31 : 2 1 3 4

On the diagram the pitch hinge is indicated by number . 2429 ?

Question 38-32 : 3 2 1 4

To ensure the centre of pressure of a rotor blade acts through the centre of ?

Question 38-33 : A weight is placed along the length of the blade forward of the main spar the aerofoil is designed to ensure the centre of pressure is in the correct location weights are located at the tip of the blade which are adjusted at manufacture to ensure the centre of gravity is in the correct location trim tabs are fitted to the tailing edge of the blade to adjust the centre of pressure

The rotor blades that are most sensitive to humidity are those made of ?

Question 38-34 : Wood metal composite materials plastic

The purpose of the blade tip cap is .1 to reduce induced drag.2 to increase ?

Question 38-35 : 1 2 3 1 2 2 3 1 3

The purpose of the aluminium mesh which is manufactured within the skin of some ?

Question 38-36 : To provide protection against lightning strikes to form the shape of the blade and to allow the lay up of the fibre glass skin to provide a superior bond between the skin and the foam core providing a strong rigid section to transfer flight loads to the skin

The purpose of a main rotor blade tracking check is to ensure ?

Question 38-37 : That all blades have the same tip path plane the correct coning angle that the neutral control settings are correct that the pitch angle for all blades is absolutely equal

The most difficult material from which to manufacture a homogeneous series of ?

Question 38-38 : Wood metal composite materials plastic

The main spar of a main rotor blade is at approximately ?

Question 38-39 : 25% of the chord 35% of the chord 40% of the chord 50% of the chord

Modern tail rotor blades are usually manufactured from ?

Question 38-40 : Composite materials metal wood carbon fibre