Aerodynamics

Question 1

Absolute altitude

Answer 1

The altitude above ground level (AGL)

Question 2

True Altitude

Answer 2

Average altitude above sea level or MSL

Question 3

Indicated altitude

Answer 3

Altitude on an altimeter that has been calibrated to sea level performance

Question 4

Pressure altitude

Answer 4

Altitude on an altimeter that has been set to reference sea level conditions

Question 5

Describe why an airfoil stalls and recovery procedures

Answer 5

An airfoil stalls when the critical AOA is exceeded. There are two types of stalls:power off and power on

To recover 
Max-smoothly add power
Relax-relax our of critical angle of attack
Roll-roll our of asymmetric attitude
DO NOT RAISE FLAPS

Question 6

Describe Bernoulli’s Law

Answer 6

Total pressure equals static pressure plus dynamic pressure

As velocity increases dynamic pressure causing a drop in static pressure, assuming density remains constant

Question 7

What is Density altitude?

Answer 7

Pressure altitude corrected for nonstandard temperature

Most important factor in aircraft performance

As density altitude increases performance decreases due to less air molecules for propellers to generate thrust and lift from

Question 8

Describe the effect of temperature on performance

Answer 8

Higher temperatures make the aircraft fly higher and equal a lower altimeter setting

Lower temperature makes the aircraft fly lower and equals a higher altimeter setting

Cold weather corrections must be applied when temperature is 0 def C or less (table found in FIH)

Question 9

Describe the effects of the Fowler flaps

Answer 9

Fowler flaps move aft and down producing significant modifications in camber and wing surface area. Deflection increases the chord and wing area and if AOA is not changed the coefficient Of lift will increase with flaps extended

Question 10

Understand fin stalls and recovery procedures

Answer 10

Fin stalls are produced from very violent uncomfortable maneuvers

High AOA, low airspeed and high rudder deflection

To recover smoothly reduce rudder deflection and recenter the ball. DO NOT ABRUPTLY APPLY FULL OPPOSITE RUDDER

Question 11

Define Parasitic and Induced Drag

Answer 11

Parasitic drag increases with Velocity, consists of

• interference drag (surface abnormalities)
• profile drag (skin friction)

Induced drag is a function of AOA

Question 12

Critical field length

Answer 12

Is the distance an aircraft can accelerate, experience engine failure (Vcef) and either continue the takeoff or abort in the same distance

Question 13

Critical Engine Failure speed

Answer 13

Is the speed at which an aircraft can accelerate, experience engine failure, and either continue the takeoff or abort the takeoff

Question 14

Refusal speed

Answer 14

Maximum speed an aircraft can accelerate on 4 engines and then stop within runway available

If Vref > Vr then use Vr
If Vref < Vr then you have split markers, use accel time check

Question 15

Vmca Minimum aircraft control speed

Answer 15

Minimum speed to maintain directional control

Question 16

MFLMETO

Minimum field length for Max effort Takeoff

Answer 16

Runway required to accelerate to Vr (decision speed) experience engine failure and either stop or continue to 1.05 Vmu4 (engine unstick speed)
DOES NOT GUARANTEE Vmca3

Question 17

What are two instances one would fly below Vmca?

Answer 17

HAAR and max effort takeoffs

Question 18

What is service ceiling?

Answer 18

Altitude at which MCP is 100 ft/min

Question 19

Describe best rate of climb and best angle of climb

Answer 19

Rate of climb- best climb performance over time

Angle of climb-used for obstacle clearance, most altitude gained over shortest distance

Question 20

Does a heavier aircraft descend faster than a lighter aircraft?

Answer 20

No. Lighter aircraft descend faster and are more maneuverable

Question 21

Understand the implications of low altitude threat reactions

Answer 21

At 0G maneuver you will lose 32ft/ s which is egregious at low altitudes

Negative G bunt maneuver recovery will not be instantaneous, account for lag at low altitudes

Wings are not level with airfoil, therefore at 10deg bank angle one must climb 10 feet for 10 more deg AoB to satisfy ground clearance

Question 22

Discuss Load limits

Answer 22

Load limits assumed that Weight and fuel weights are within limitations

Load limits also assume smooth application of force on flight controls

If not, these may occur
Torsion moments-twisting of a body by the exertion of forces (aileron roll)
Bending moment- transverse deflection of a body perpendicular to its longitudinal axis (wing relieving fuel can help this)
Shearing moment-abrupt forces applied to a surface may cause damage by deformation of a plane from slippage

Question 23

What maneuvers are prohibted?

Answer 23

Spins, nose high attitudes, hard rudder deflections, steel dives

Question 24

Describe basic aerodynamic forces

Answer 24

Lift = 1/2(to)Cl(V^2)S

Drag=1/2(ro)Cd(V^2)S

To increase lift, increase Cl through AOA or S at constant density and velocity

AOA increases with wing tilt relative to the wind

Question 25

What is center of pressure?

Answer 25

Center of pressure is where the resultant aerodynamic forces act

Question 26

What is the chord line?

Answer 26

A straight line from Leading edge to trailing edge

Question 27

If Fluid is air then force is….

Answer 27

An aerodynamic Force