Ground Unit 1

Question 1

Define Camber

Answer 1

The curvature of an airfoil

Question 2

Chord Line

Answer 2

An imaginary line drawn from the leading edge to the trailing edge of the cross section of an airfoil.

Question 3

Angle Of Attack

Answer 3

The angle between the cord line of the wing and the relative wind (which is parallel to the flight path)

Question 4

Angle of Incidence

Answer 4

The angle formed from the cord line of the wing and the longitudinal axis of the airplane . This is based in airplane design and can not be changed by the pilot.

Question 5

Center of Pressure

Answer 5

The point along the chord line at which all the aerodynamic forces are considered to be concentrated

Question 6

Dihedral

Answer 6

The angle at which the wings are slanted upward from the root of the wing to the tip

Question 7

Relative wind

Answer 7

The direction of airflow produced by an object passing through the wind . Is normally parallel and opposite the direction of flight for an airplane.

Question 8

Washout

Answer 8

a wing design in which the wing is twisted such that the angle of incidence is less at the wingtip than at the root. This allows the ailerons to remain effective after the wing root begins to stall.

Question 9

How do a monocoque fuselage and a truss type fuselage differ?

Answer 9

In a truss fuselage the skin is supported by complex framework of complex structural members that bear the load on the fuselage.

The Momocoque type fuselage has little to no internal bracing other than bulkheads and the outer skin bears the main weight of the fuselage.

Question 10

What are the two types of wings?

Answer 10

Cantilever- Requires no external bracing and is supported by spars ribs and stringers.

SemiCantilever- Which is supported externally by struts externally and spars and ribs internally

Question 11

Describe the structural components of the wing.

Answer 11

Spar- is the main structural component of the wing. It is attached to many ribs which shape the camber

Question 12

Brenoulli’s Principle

Answer 12

The internal pressure of a fluid (Liquid or Gas) decreases at a points where the speed of the fluid increases.

Question 13

How does angle of attach relate to stalls?

Answer 13

A wing stalls at the same angle of attack no matter what the wing load or airspeed is.

Question 14

How does a spin develop?

Answer 14

A spin developes when one wing is more stalled than the other wing. This can happen at any airspeed or any angle of attack.

Question 15

How does a stall develop?

Answer 15

Any time the critical angle of attack is exceeded.

Question 16

When does frost form? What implication will this have on the performance of the wing?

Answer 16

When the temperature of a surface is below the dew point. The frost on the wing will cause an earlier point of separation from the wing and will decrease lift and increase friction and drag

Question 17

What is ground effect?

Answer 17

Ground effect results from the interference of the ground surface with the airflow patterns about an airplane.

Question 18

What will ground effect do?

Answer 18

The vertical component of the airflow about the wing is constricted thus altering the upwash, downwash, and wingtip vortices.

Question 19

What will ground effect actually do to the airplane?

Answer 19

The wing will require a lower angle of attack (in ground effect) to produce the same lift coefficent

Question 20

When will a plane enter ground effect?

Answer 20

Ground effect begins when the airplane is within one wingspan of the ground. It is most recognized when the plane is within 1/2 the wingspan to the ground.

Question 21

What can ground effect cause the airplane to do?

Answer 21

Ground effect can cause the airplane to float on landing. Ground effect can also cause the airplane to become airborn with insufficent airspeed to stay in flight above the area of ground effect.

Question 22

What determines the longitudinal stability of an airplane?

Answer 22

The location of the center of gravity (CG) to the center of lift

Question 23

How will an inherantely stable airplane handle a disrupt in longitudinal or positional stability

Answer 23

An inherantly stable airframe will return to its initial position after the upset.

Question 24

What is the problem when the CG of the airplane is to far AFT of CG limits?

Answer 24

The plane will be unable to recover from stalls or spins and be less stable at all airspeeds.

Question 25

When is the torque effect of an airframe greatest? ( 3 things)

Answer 25

At high angles of attack, low airspeeds, and high power.

Question 26

What is P-factor?

Answer 26

Asymmetric propeller loading- causes the airplane to yaw to the left when at high angles of attack because the descending right blade of the prop as a higher angle of attack and thus creates more thrust.

Question 27

What is load factor?

Answer 27

Load factor refers to the additional weight carried by the wings due to the airplanes weight plus the centrifugal force.

Question 28

What determines the amount of load that can be imposed on the airframe?

Answer 28

Varies directly to the airspeed and the excess lift available

Question 29

What will load factor do to the stall speed?

Answer 29

As the load factor increases the stall speed will increase.

Question 30

What is the relationship between load factor and bank angle?

Answer 30

As bank angle increases the load factor increases because the airplane has to carry the airplanes weight and centrifugal force from the turn.

Question 31

What is the purpose of wing flaps?

Answer 31

Extending the flaps increses the wing camber and angle of attack. This increases the wing lift and induced drag .

Question 32

On approach what will flaps allow the pilot to do?

Answer 32

Flaps will allow the pilot an increased rate of descent without increasing the airspeed of the plane.

Question 33

What control surface allows for manipulation of the airplane about the vertical axis?

Answer 33

The rudder allows the plane to YAW around the vertical axis.

Question 34

What are the four forces that act on an airplane in flight

Answer 34

Thrust- produced by the prop Lift- produced by the wings Drag- Induced and parasite Weight- mass x gravity

Question 35

When are the forces on an airplane at equlibrium?

Answer 35

In unaccelerated flight

Question 36

In straight and level flight what is the relationship between lift weight thrust and drag?

Answer 36

Lift equals weight and thrust equals drag.

Question 37

In order to develop a spin what condition must the aircraft be placed?

Answer 37

In order for the spin to develop the wing must be COMPLETELY stalled first.

Question 38

In a spin which wing is stalled?

Answer 38

BOTH

Question 39

How will frost affect takeoff performance.

Answer 39

Frost will not affet the camber of the wing but will affect the flow of the air over the camber of the wing. The ice will disrupt the smooth airflow which results in earlier separation and increased drag.

Question 40

What is the main hazard frost imposes to the aviator?

Answer 40

Frost spoils the smooth airflow of over the wing therefore decreasing the lift capabilities... **Frost DOES NOT change the aerodynamic shape of the wing.

Question 41

How does frost affect the lifting capability?

Answer 41

Frost will prevent the airplane from becoming airborne at the normal takeoff speed.

Question 42

What is ground effect?

Answer 42

The interference of the surface of the earth with the airflow patterns about an airplane.

Question 43

What must the pilot have in mind as a result of ground effect?

Answer 43

Induced drag will decrease, therefore any excess speed at flare will cause excessive floating.

Question 44

What will ground effect cause on takeoff?

Answer 44

The plane will lift off at a speed that is not sufficient airspeed

Question 45

How do you calculate load factor?

Answer 45

Load Factor = ( Total load supported by the wings / Total weight of the airplane )

Question 46

What is Drag? | What are the two types of Drag?

Answer 46

Drag is the rearward directed force resulting from the forward movement of the airplane through the air. It acts parallel to and in the same direction as the relative wind. Induced Drag Parasite Drag

Question 47

What is induced Drag?

Answer 47

Unavoidable byproduct of lift. Drag= 1/ ((velocity)^(1/2)) When the wing is creating lift there is increased pressure on the underside of the wing and decreased pressure on the upper camber of the wing. At the wing tip these pressures tend to equalize in a lateral flow of air from the underside (High Pressure) to the upper side (Low Pressure) creating a wingtip vortex. These vortecies shift the lift component rearward and create drag. Induced drag is greatest at low speed and high angle of attack

Question 48

What is Parasite Drag?

Answer 48

The drag of the airplane passing through the air. P.Drag = (Velocity)^(1/2) 1. Skin Friction 2. Form Drag- caused by the frontal surface of the airplane presented of the airstream. 3. Interferance Drag- Interferance of the air passing through adjacent parts of the airplane. 4. Frost- Increases friction of the airframe passing through the air causing an increased separation.

Question 49

What is L/D max?

Answer 49

The airspeed at which the airframe gets the maximum amount of lift with min amount of drag. It is the point of lowest Induced (Decreases as airspeed increases) and paracite drag ( increases as airspeed increases)

Question 50

What is Adverse Yaw?

Answer 50

When applying the aileron to bank the plane the lowered aileron (On the raised wing) produces more lift and drag than the raised aileron (on the lowered wing)