A103 Aerodynamic Principles

Question 1

identify and define basic elements of an airfoil

Answer 1

leading edge, trailing edge, camber

Question 2

list the four forces acting on an airplane in flight

Answer 2

lift(most important), drag, thrust, weight

Question 3

weight

Answer 3

opposes lift, downward pull of gravity

Question 4

lift

Answer 4

upward force

Question 5

thrust

Answer 5

forward force(engine power) F=M*a

Question 6

drag

Answer 6

opposes thrust- backward or retarding force

Question 7

describe ground effect

Answer 7

phenomenon of less induced drag close to ground effected closer to ground. Takeoff/Landing, more noticeable on low wing aircraft

Question 8

explain aerodynamic stall**

Answer 8

when you exceed the critical angle of attack

Question 9

explain stall recovery

Answer 9

reduce critical angle of attack, smoothly apply max power, adjust power as needed, recover to lever flight, avoid secondary stall (Max relax roll)

Question 10

List the aerodynamic forces present at spin entry

Answer 10

stall and yaw, one wing is slightly stalled more than the other.

Question 11

describe the three axes of rotations

Answer 11

vertical, horizontal, and yaw

Question 12

Two types of drag

Answer 12

parasite drag, induced

Question 13

parasite drag

Answer 13

the faster you fly, you exponentially increase parasite drag

Question 14

three types of parasite drag

Answer 14

Form drag, interference, and skin friction

Question 15

form drag(physical)

Answer 15

from wake turbulent wake cause by airflow around a structure, also depends on size and shape of structure

Question 16

interference drag(not part of airplane)

Answer 16

cause by weapons or other additional stuff on airplane

Question 17

skin friction

Answer 17

roughness of airplane surfaces, rivet heads, or irregularities(bugs/dirt)

Question 18

induced drag

Answer 18

drag created by the production of lift, inversely proportional to square of speed

Question 19

total drag L/d max airspeed

Answer 19

parasite +induced

Question 20

stall recovery

Answer 20

throttle-idle
rudder-opposite to spin direction
Control stick-ease forward
rudder -neutral when rotation stops
flaps- cruise
control stick- pull to get of of dive

Question 21

total drag- L/d max airspeed

Answer 21

parasite +induced

Question 22

stall recovery check list

Answer 22

throttle-idle
rudder-opposite to spin direction
Control stick-ease forward
rudder -neutral when rotation stops
flaps- cruise
control stick- pull to get of of dive

Question 23

Longitudinal axis(roll axis)

Answer 23

ailerons

Question 24

latitudinal axis(pitch)

Answer 24

elevators

Question 25

yaw axis

Answer 25

yoke or stick

Question 26

explain how airplanes turn in flight

Answer 26

horizontal component of an airplane cause an airplane to turn. when vertical component of lift equals weight aircraft will neither gain nor lose altitude

Question 27

define adverse yaw

Answer 27

when rolling into a turn, outside wing produces more lift, induced drag s a product of creation of lift so total drag on that wing increases. Causes yaw toward he outside turn. Use rudder to compensate to correct adverse yaw

Question 28

define load factor

Answer 28

g forces, feel heavier in turn, pilot input or environment. Increases as angle of bank increases.

Question 29

load factor and stall speed

Answer 29

Increasing load factor will cause an airplane to stall at a higher speed

Question 30

list the four turning tendencies in propeller driven aircraft

Answer 30

torque, gyroscopic thrust(right turning tendencies), Pfactor, spiraling slipstream

Question 31

torque

Answer 31

propeller rotates clockwise, which tends to rotate airplane counterclockwise about the longitudinal axis

Question 32

identify and define maneuvering speed

Answer 32

Max airspeed you can use full, abrupt control movement without over stressing the airframe

Question 33

pfactor

Answer 33

uneven angles of attack between ascending and descending blades. unequal thrust cause yaw to the left

Question 34

spiraling slipstream

Answer 34

slipstream from propeller wraps around fuselage and hits the left vertical fin, cause tail to move right and nose yaw to the left.