Flight Controls

Question 1

Answer 1

Question 2

Flight Controls Description and Operation

Answer 2

The CH-47F Flight Control system uses two Flight Control Hydraulic Systems, two digital automatic flight control systems (DAFCS), first and second stage mixing units secondary controls that add features, and the linkage and connecting rods that connect and transmits control movements from the cockpit controls to the rotor heads

Question 3

The Flight Control System is divided into seven main sections

Answer 3

(1) Cockpit Controls

(2) Closet Controls

(3) First and Second-Stage Mixing Controls

(4) Forward Upper Controls

(5) Tunnel Controls

(6) Aft Fuselage Controls

(7) Aft Upper Controls

Question 4

The purpose of the flight control system is to

Answer 4

transmit control movements from the cockpit to the swashplates.

Question 5

Control inputs from the cockpit are transmitted through ________ _________ to the rotary wing assemblies.

Answer 5

Control inputs from the cockpit are transmitted through mechanical linkage to the rotary wing assemblies.

Question 6

_______ _______ assist in the mechanical linkage movements, and without ______ ________ the flight controls can not be moved.

Answer 6

Hydraulic actuators assist in the mechanical linkage movements, and without hydraulic pressure the flight controls can not be moved.

Question 7

The forward tilt of the forward transmission is __ degrees while the aft transmission is __ degrees.

Answer 7

The forward tilt of the forward transmission is 9 degrees while the aft transmission is 4 degrees.

Question 8

The preset forward tilt of these two transmissions provides a forward propulsive force to aid in _______ ________.

Answer 8

The preset forward tilt of these two transmissions provides a forward propulsive force to aid in ground taxiing.

Question 9

Programmed cyclic tilt of the rotor discs (forward and aft) is provided by the _________ _________ ________ (___J system which are electrical actuators attached to the swashplates.

Answer 9

Programmed cyclic tilt of the rotor discs (forward and aft) is provided by the Longitudinal Cyclic Trim (LCT) system which are electrical actuators attached to the swashplates.

Question 10

Answer 10

Question 11

As airspeed increases ________ ________ increases to minimize fuselage pitch and attitude changes.

This directs the propulsive force more forward at higher airspeeds; reduces _______ _______, stress on the _______ _______ ______, fuselage ______ __ ______, allowing for a higher velocity, not to exceed airspeed limits.

Answer 11

As airspeed increases forward tilt increases to minimize fuselage pitch and attitude changes.

This directs the propulsive force more forward at higher airspeeds; reduces blade flapping, stress on the aft vertical shaft, fuselage angle of attack, allowing for a higher velocity, not to exceed airspeed limits.

Question 12

Four control axis are identified by the helicopter response to the control input:

Answer 12

(1) Thrust

(2) Pitch

(3) Roll

(4) Yaw

Question 13

When the thrust control is raised, the ______ ______ _______ of all six rotor blades increases, causing the aircraft to ascend.

Answer 13

When the thrust control is raised, the collective pitch angle of all six rotor blades increases, causing the aircraft to ascend.

Question 14

Longitudinal control of tandem helicopters is accomplished through _______ _______ ______ (___).

Answer 14

Longitudinal control of tandem helicopters is accomplished through differential collective pitch (DCP).

Question 15

____ varies the amount of thrust produced by the forward and aft rotors systems, creating pitch attitude changes of the fuselage in the pitch axis.

Answer 15

DCP varies the amount of thrust produced by the forward and aft rotors systems, creating pitch attitude changes of the fuselage in the pitch axis.

Question 16

Forward cyclic input _______ ______ (collective pitch) in the forward rotor system and _______ ______ in the aft rotor system an equal amount, causing the aircraft to pitch nose down and increase airspeed.

Answer 16

Forward cyclic input decreases thrust (collective pitch) in the forward rotor system and increases thrust in the aft rotor system an equal amount, causing the aircraft to pitch nose down and increase airspeed.

Question 17

Aft cyclic input ______ the thrust in the forward rotor system and ______ thrust in the aft rotor system causing the aircraft to pitch nose up, decrease airspeed and move aft.

Answer 17

Aft cyclic input increases the thrust in the forward rotor system and decreases thrust in the aft rotor system causing the aircraft to pitch nose up, decrease airspeed and move aft.