Jeppesen Oral- Chapter 1 ( Aircraft Structural Assembly & Rigging)

Question 1

What is the function of a vortex generator?

Answer 1

Delays separation of the boundary layer

Question 2

What are the three axes of an aircraft?

Answer 2

Longitudinal, lateral, vertical

Question 3

What are the three primary flight controls of an aircraft

Answer 3

Ailerons, rudder, elevator

Question 4

Name several secondary flight controls and what is their function?

Answer 4

Trime tabs, balance tabs, anti-servo tabs, servo-tabs, spring tabs

Designed to trim the aircraft for a particular speed and attitude

Question 5

Name several types of auxiliary flight controls and describe their general purpose?

Answer 5

High lift devices, slats, slots, flaps, speed breaks,

Question 6

What is a servo trim tab?

Answer 6

Axially control, controlled via cockpit action, creates aerodynamic force to assist in moving control surface

Question 7

What is a spring tab?

Answer 7

Axially control designed to aid movement of primary control surfaces at high speeds when control forces becomes high

Question 8

What is a balance trim tab?

Answer 8

Auxiliary control that creates aerodynamic force which assist in moving control surface.

Actuated via a control rod connected to fixed surface on the same side as horn tab

Question 9

What are the four common types of high lift devices?

Answer 9

Leading edge flaps, trailing edge flaps, slats, slots

Question 10

Describe some of the tools used to check control surface travel?

Answer 10

Universal propeller protractor or special control surface protractor

Question 11

Name three mechanical methods by which flight control systems may be actuated?

Answer 11

Cables, push-pull rods, torque tubes

Question 12

What is a fairlead?

Answer 12

Device to prevent a cable from rubbing on the aircraft structure

Question 13

What are the most likely places for a control cable to wear or break?

Answer 13

Where cables pass over pullers or through fairleads

Question 14

What information is required before a cable rigging chart can be used?

Answer 14

Ambient temperature and the cable size

Question 15

What is the function of a cable tension regulator?

Answer 15

Automatically adjusts the cable tension to compensate for expansion and contraction of aircraft structure

Question 16

Describe the function of a rotorcraft collective pitch.

Answer 16

Causes each rotor blade to change its pitch by the same amount

Question 17

Describe the function of a rotorcraft cyclic pitch control.

Answer 17

Tilts the main rotor disc by change the pitch angle of each rotor blade during its rotation

Question 18

What mechanism is most commonly used to compensate for the torque produced by the main rotor of a helicopter?

Answer 18

Tail rotor (anti-torque rotor)

Question 19

How is the amount of the thrust produced by the tail rotor controlled?

Answer 19

By moving the foot pedals

Question 20

Why should control surfaces be locked when an aircraft is parked?

Answer 20

To prevent damage from the wind

Question 21

Why is it especially important that the leading edge of a wing and the upper surface of the forward half of the wing be kept free of dents and any dirt or contamination?

Answer 21

The air flowing over this portion of the wing must be smooth to produce the maximum amount of lift. If the surface is rough or dirty, the airflow will be distorted and lift will be lost.

Question 22

What is meant by the angle of incidence of an airplane wing?

Answer 22

The acute angle that is formed between the chord line of an airfoil and the longitudinal axis of the aircraft on which it is mounted.

Question 23

What causes parasite drag on an airplane?

Answer 23

The friction of the air flowing over the surface.

Question 24

What is the function of lateral dihedral in the wings of an airplane?

Answer 24

Lateral dihedral gives the aircraft roll stability, or stability about the longitudinal axis.

Question 25

What is the purpose of a stall strip on an airplane wing?

Answer 25

Stall strips distort the air flowing over the top of the wing in the root areas at high angles of attack. They cause the root of the wing to stall out at a lower angle of attack than the portion of the wing ahead of the ailerons.

Question 26

What is the function of a servo tab on an aircraft control surface?

Answer 26

A servo tab produces an aerodynamic force on a control surface that aids the pilot in moving the surface.

Question 27

What causes dissymmetry of lift produced by the rotor of a helicopter?

Answer 27

The forward speed of the helicopter produces dissymmetry of lift. The rotor blade which is traveling forward as the helicopter is flying produces more lift than the blade that is traveling rearward.

Question 28

Why do single-rotor helicopters use an auxiliary rotor on their tail?

Answer 28

The thrust from the auxiliary rotor on the tail of the helicopter counteracts the torque produced by the main rotor.

Question 29

Why is it important that the leading edge of a supersonic airplane wing be kept free from dents and damage?

Answer 29

A sharp leading edge allows an oblique shock wave to attach to the airfoil in supersonic flight. If the leading edge is dented or blunt, a normal shock wave will form and slow the air immediately behind it to a subsonic velocity.

Question 30

Why are the control cables of large airplanes normally rquipped with automatic tension regulators?

Answer 30

The large amount of aluminum in the aircraft structure contracts so much as its temperature drops in flight that the control cables could become dangerously loose. The automatic tension regulators keep the cable tension constant as the dimensions of the aircraft change.

Question 31

Why is it important that the blades of a helicopter rotor system be in track?

Answer 31

If the blades are not in track, vertical vibration can develop.

Question 32

Why is it important that any repairs to the control surfaces of an airplane not change their original condition of balance about their hinge line?

Answer 32

A control surface that is out of static balance can flutter in certain flight conditions. Flutter normally tears the surface off the aircraft.