Highspeed Wings and Surface Controls, and High Lift Devices

Question 1

The shape of the wing, when viewed from above looking down onto the wing, is called a

Answer 1

planform

Question 2

refers to the shape and layout of the fuselage and wing of a
fixed wing aircraft

Answer 2

Planform

Question 3

One of the earliest wing
planforms built.

Answer 3

Rectangular Wing

Question 4

are constant chord wings which
are the easiest to
manufacture, which is why
most of the early aircrafts
have such wing planforms.

Answer 4

Rectangular wings

Question 5

▪ Most aerodynamic efficient type of wing because of the ____________ spanwise lift distribution it generates in flight.

Answer 5

elliptical wing

Question 6

This spanwise lift distribution is ideal as it induces the lowest
possible drag compared with all other wing planforms.

Answer 6

Elliptical Wing

Question 7

It is the basis for efficiency for all wing planforms.

Answer 7

Elliptical Wing

Question 8

Difficult to manufacture.

Answer 8

Elliptical Wing

Question 9

Designed to modify the rectangular
wing planform where the chord
essentially varies along the span of
the wing to generate an elliptical
spanwise lift distribution.

Answer 9

Tapered Wing

Question 10

However, does not equal the efficiency provided by the elliptical wing which makes it a good compromise between efficiency and manufacturability.

Answer 10

Tapered Wing

Question 11

are low aspect ratio
wings that are used in all flight
regimes (subsonic, transonic, and
supersonic).

Answer 11

Delta wings

Question 12

Efficient for high speeds and exhibits
high drag at low speeds.

Answer 12

Delta Wing

Question 13

Offers large area for the shape which
improves maneuverability and wing
loading.

Answer 13

Delta Wing

Question 14

An example of a delta wing is an ________ employed in a
supersonic Concorde.

Answer 14

ogive wing

Question 15

___________ is highly efficient at very high speeds due to the
complex mathematical shape it exhibits to minimize aerodynamic
drag at supersonic speeds.

Answer 15

Ogive wing

Question 16

They are complex and difficult to manufacture.

Answer 16

Delta Wing

Question 17

▪ It reduces the aerodynamic drag as the
aircraft fly at high-subsonic and transonic
speeds.

Answer 17

Swept Wing

Question 18

By sweeping the wings backward, it can
reduce the _________ seen by the
airfoil which delays the onset of drag brought about by fluid compressibility near
the speed of sound.

Answer 18

effective airspeed

Question 19

Forward swept wing stalls the ________ first before the _______ which makes it undesirable for aircraft controllability.

Answer 19

wing tip; wing root

Question 20

It produces ___________ when put under load which puts greater stress on the _________.

Answer 20

wing twisting; wing root

Question 21

Designed to compensate for which regimes each planform are efficient.

Answer 21

Variable Sweep Wings

Question 22

– efficient for
high speeds such as supersonic and transonic flights.

Answer 22

Swept back wings

Question 23

– work best for low speeds like subsonic flights.

Answer 23

Unswept wings

Question 24

Mechanical complexity outweighs the compromise it offers.

Answer 24

Variable Sweep Wings

Question 25

Wing Planforms

Answer 25

Variable Sweep Wings Swept Wing Delta Wing Tapered Wing Elliptical Wing Rectangular Wing

Question 26

Surface Controls

Answer 26

AILERON- ROLL- LONGITUDINAL- LATERAL ELEVATOR/STABILATOR- PITCH-LATERAL-LONGITUDINAL RUDDER- YAW-VERTICAL-DIRECTIONAL

Question 27

They are mounted on the outer part of the wing trailing edge (or near the wing tips) and move opposite relative to each other.

Answer 27

Ailerons

Question 28

Controlled by yokes, control wheel or control stick

Answer 28

Ailerons

Question 29

Aileron deflected upward – Aileron deflected downward –

Answer 29

decrease in wing camber – decrease in lift. increase in wing camber – higher lift

Question 30

Since there is a different value of lift in each wing, the corresponding drag is also different.

Answer 30

Adverse Yaw

Question 31

The difference in drag creates a yawing action of the airplane from leaning towards the wing which produces greater drag.

Answer 31

Adverse Yaw

Question 32

Resolved using rudder application, but other forms of controlling the adverse yaw were engineered as a solution:

Answer 32

1. Differential Ailerons 2. Frise-type Ailerons 3. Coupled Ailerons and Rudder 4. Flaperons

Question 33

▪ Operated in such a way that one aileron is deflected at a larger angle corresponding to the control wheel input.

Answer 33

Differential Ailerons

Question 34

Usually done on the aileron deflected upwards where drag values are small.

Answer 34

Differential Ailerons

Question 35

▪ Operated by pivoting on an offset hinge

Answer 35

Frise-type Ailerons

Question 36

As the aileron is deflected upward, its leading edge is exposed to the airflow on the bottom surface to create drag.

Answer 36

Frise-type Ailerons

Question 37

▪ It operates by automatic rudder deflection for every control input done on the control wheel.

Answer 37

Coupled Ailerons and Rudder

Question 38

Control surfaces that combine the aspect of ailerons and flaps.

Answer 38

. Flaperons

Question 39

In addition to the rolling of the aircraft, flaperons can be __________ to function much the same as a dedicated set of flaps

Answer 39

lowered together

Question 40

A mechanical device called a "__________" is used to combine the pilot's input into the flaperons.

Answer 40

mixer

Question 41

▪ It controls pitch about the lateral axis. ▪ It functions to turn the nose of the aircraft up or down. ▪ Controlled by pulling or pushing the control wheel in a forward or backward position.

Answer 41

Elevators

Question 42

The following are configurations of elevator in aircraft design:

Answer 42

1. T-Tail Design 2. Stabilator 3. Canard

Question 43

Elevators employed for the ______________ designs is away from the effects of downwash from the propeller and airflow around the wing during flight conditions.

Answer 43

T-tail

Question 44

Functions just like an elevator but it is essentially a one-piece control surface rotated about a central hinge point.

Answer 44

Stabilator

Question 45

A movable horizontal surface that acts as an elevator.

Answer 45

Stabilator

Question 46

Pushing the control column forward – Pulling the control column aft –

Answer 46

trailing edge of stabilator rises – pitch down the trailing edge of stabilator lowers – pitch up

Question 47

▪ Utilize concepts of two lifting surfaces

Answer 47

Canard

Question 48

acts as a control surface near the nose of the aircraft design to create lift to pitch the nose up

Answer 48

canard

Question 49

designs produce a downward force to prevent the nose of the aircraft from rotating downward.

Answer 49

Aft-tail

Question 50

Rudders

Answer 50

Controls the movement about the vertical axis.

Question 51

It is hinged to a fixed vertical surface called the _____________ and is controlled by rudder pedals.

Answer 51

fin or vertical stabilizer

Question 52

_______________ effectiveness increase with speed, and therefore, large deflections at slow speeds, and small deflection at high speeds may be employed to obtain desired reactions.

Answer 52

Rudder

Question 53

Common configuration of the vertical surfaces is/are:

Answer 53

1. V-Tail

Question 54

▪ Combine the functions of elevators and rudders by employ

Answer 54

V-Tail

Question 55

▪ Usually called ruddervators since it acts as both elevators and rudders.

Answer 55

V-Tail

Question 56

are movable surfaces or, in some cases, stationary components that are designed to increase lift during some phases or conditions of flight.

Answer 56

High Lift Devices

Question 57

Three groups of high lift devices:

Answer 57

1. Trailing-Edge Flap 2. Leading Edge High Lift Devices or Leading-Edge Devices 3. Boundary Layer Control

Question 58

is a small auxiliary airfoil located near the rear of a main airfoil which can be deflected about a given line where it is hinged.

Answer 58

Trailing-Edge Flap

Question 59

Types of trailing edge flap:

Answer 59

i. Plain Flap ii. Split Flap iii. Slotted Flap iv. Fowler Flap

Question 60

iii. Slotted Flap

Answer 60

a. Single Slotted Flap b. Double Slotted Flap c. Triple Slotted Flap

Question 61

* Simplest and earliest type of high lift device. An airfoil shape which is hinged at the trailing edge of a wing, enabling it to rotate upward or downward.

Answer 61

Plain Flap

Question 62

Increases Lift through mechanically increasing the effective camber of the wing section.

Answer 62

Plain Flap

Question 63

Reduces the zero lift AOA without affecting the lift curve slope.

Answer 63

Plain Flap

Question 64

Only the bottom part of the airfoil is movable which leaves the upper geometry of the airfoil unchanged during flap deflection.

Answer 64

Split Flap

Question 65

Deflection results in a decrease in zero lift AOA which is similar to the plain flap. However, since the upper geometry was not altered during the deflection, it is not cambered as much as the lower part and the effects of separation is less marked so that performance at high incidence is improved.

Answer 65

Split Flap

Question 66

* A slotted flap opens a gap or slot between the flap and the main airfoil when it is deflected

Answer 66

Slotted Flap

Question 67

The ___________- is at higher pressure than the air at the upper surface, thus when the slot or gap is _______, the air beneath is blowing though the slot.

Answer 67

air beneath; opened

Question 68

* Similar to the single slotted flap, except that it employs two slots * Almost doubles the advantages offered of a single slotted flap.

Answer 68

Double Slotted Flap

Question 69

* Basically, an extension of a double slotted flap, which employs three slots. * Produce the highest increment of lift coefficient.

Answer 69

Triple Slotted Flap

Question 70

* Employs a special mechanism such that when it is deployed, not only it deflects downward but also translates or tracks to the trailing edge of the wing.

Answer 70

Fowler Flap

Question 71

are great instruments to increase the critical angle of attack and, therefore, delay the stall.

Answer 71

Leading edge devices

Question 72

Types of Leading-Edge Devices:

Answer 72

i. Fixed Slot ii. Leading-Edge Slat (Movable Slat) iii. Leading-Edge Flap (Droop-Snoot) iv. Leading-Edge Cuff v. Krueger Flap

Question 73

* It directs airfoil in the upper surface of the wing which in turn delays flow separation at higher AOA. * Does not alter the camber but still generates high values of maximum lift coefficient because the stall is delayed at higher AOA.

Answer 73

Fixed Slot