Performance & Limitations

Question 1

4 Dynamic Forces

Answer 1

Lift- Upward Acting Force

Gravity (weight)- Downward Acting Force

Thrust- Forward

Drag- Backward

Question 2

Sum of opposing forces is equal

Answer 2

Steady-state, straight and level unaccelerated flight

Question 3

Airfoil

Answer 3

Air moving over surface = lift

Wings, horizontal & vertical tail surfaces, propellers

Question 4

Angle of Incidence

Answer 4

Angle formed by Longitudinal Axis & Chord of wing, fixed and cannot be changed

Question 5

Relative Wind

Answer 5

Direction of airflow with respect to wing

Wing forward & downward- relative wind backward & upward

Flight path and relative wind always parallel but travel in opposite directions

Question 6

Angle of attack

Answer 6

Angle wing chord line & direction of relative wind

Question 7

Bernoullis Principle

Answer 7

Pressure of fluid decreases at points where the speed of fluid increases

High speed flow - low pressure
Low speed - high pressure

Pressure decrease of pressure above wing and increase below produces lift

Question 8

Factors affecting lift and drag

Answer 8

1. Wings (Pilot can change with flaps)
2. Airfoil shape (upper curvature of airfoil increased, lift increased- lowering aileron/flap)
3. Angle of Attack (increased also increased lift and drag)
4. Air Velocity (air passing over wing increased lift and drag)
5. Air Density (pressure, temp, and humidity defect density which effects lift & drag- increase, increase, decrease, decrease)

Question 9

Torque Effect

Answer 9

Newton’s third law of physics- every action there is equal and opposite reaction

Internal engine parts + propeller turn one direction = equal force trying to rotate plane other direction

Question 10

Torque Effect 4 Factors

Answer 10

1. Reaction of Engine & Propeller- propeller to right is making plane roll and bank left
2. gyroscopic effect of Propeller- if axis of propeller tilted resulting force exerted 90 degrees ahead in direction of rotation
3. Corkscrewing effect of propeller- high speed rotation results in corkscrewing of slip stream moving rearward. Pushes tail to right and yaws plane to left.
4. P-factor- high angle of attack downward bite of propeller greater than bite of upward moving blade. Plane yaws left

Question 11

Centrifugal Force

Answer 11

Equal & Opposite reaction of plane changing direction, acting equal and opposite to horizontal component of lift

Question 12

Load factor

Answer 12

Actual load supported by wings divided by total weight of plane

Plane can be overloaded and increases stall speed

Question 13

Maximum load factor

Answer 13

Load factor Max during bank angle after 45-50 degrees

Turbulence could cause increase in angle of attack

Speed- flying below maneuvering plane can stall before load factor excessive, faster can be exceeded by controls or strong turbulence

Question 14

Maximum Safe (Limit) Load Factors
Normal Airplane

Answer 14

+3.8 to -1.52

Question 15

Maneuvering Speed

Answer 15

Max speed at which limit load can be imposed without causing structural damage (by gusts or full deflection of control surfaces)

Maneuvering speed increase with increased weight, decreases decreased

Question 16

LOC-I

Answer 16

Loss of control inflight
Significant deviation of aircraft from intended path

LOC-I accidents occur from uncoordinated flight, equipment malfunctions, pilot complacency, distraction, poor risk management

Question 17

Stall causation

Answer 17

Increased angle of attack, airflow separated from upper surface of wing

Question 18

Spin

Answer 18

Descent in helical path which flying aoa greater than critical aoa. Aggravated stall in slip or skid.

Question 19

Scenarios spin likely

Answer 19

Engine failure on take off (increased back pressure/uncoordinated turn)

Slipping or skidding turn from base to final (uncoordinated turn at low speed)

Engine failure on approach to landing (increased back pressure to stretch glide)

Go around with full nose up trim

Go around with improper flap retraction (retracts flaps rapidly causing rapid sink rate and instinctual back pressure)

Question 20

Spin Recovery

Answer 20

PARE
Power Idle
Ailerons Neutral
Rudder Opposite
Elevator FWD

Then neutralize rudder & begin applying back pressure to return to level

Question 21

Adverse Yaw

Answer 21

Turning left-
Down aileron on right producing more lift & drag while left aileron has less lift & drag.
This added drag attempts to pull airplanes nose in direction of raised wing. (Adverse yaw)

Question 22

Ground effect

Answer 22

Airflow around wing restricted by ground surface reducing wings upwash, downwash, and wingtip vortices

Reduced drag on landing and take off:

Excess speed during landing = significant float

Deficiency of speed during take off = marginal climb performance of inability to fly

Question 23

Empty Weight

Answer 23

Weight of airframe, engines, all permanently installed aircraft, unusable fuel

Question 24

Gross Weight

Answer 24

Maximum allowable weight (airplane + contents)

Question 25

Useful Load

Answer 25

Weight of Pilot, copilot, passengers, baggage, usable fuel, drain able oil

Question 26

Arm

Answer 26

Horizontal distance in inches from reference datum line to center of gravity of item

Question 27

Moment

Answer 27

Weight of an item multiplied by its arm, expressed in pounds-inches

Question 28

Center of gravity

Answer 28

Point at which aircraft would balance if it were possible to suspend it at that point Inches from datum

Question 29

Datum

Answer 29

Imaginary vertical plane or line from which measurements of arm are taken, established by manufacturer

Question 30

Center of Gravity Equations

Answer 30

Weight x Arm = Moment Moment/Arm = Weight Total Moment / Total Weight = Arm (CG)

Question 31

Weight Shift

Answer 31

Shifting weight around aircraft, weight remains same BUT total moment change in relation and proportion to direction and distance the weight moved Weight forward, moment decreased Weight aft, moment increases

Question 32

Weight Shift Equation

Answer 32

Weight Shifted divided by total weight Equals Change in CG divided by distance weight is shifted

Question 33

FWD Center of gravity

Answer 33

Higher Stall Speed -increased wing loading Slower cruise speed- increased drag, greater aoa to maintain altitude More stable- farther fwd from center of pressure, increases longitudinal stability Greater back elevator pressure required- longer take off roll, higher approach speeds & problems with landing flare

Question 34

Rearward center of gravity

Answer 34

Lower stall speed- less wing loading Higher cruise speed- reduced drag, smaller aoa required to maintain alt Less stable- stall & spin recovery more difficult, COG closer to COP

Question 35

Standard weights

Answer 35

Crew & pax 190 each Av gas 6 lb/gal Jet A 6.75 lb/gal Oil 7.5 lb/gal Water 8.35 lb/gal

Question 36

New avionics installed, weight and balance record required?

Answer 36

A& P mechanic or tech’s responsibility to know weight and location of changes and to compute the CG and record new empty weight and empty weight center of gravity EQCG in aircraft weight and balance record

Question 37

Wind & Aircraft Performance

Answer 37

Takeoff- headwind allows ac to reach lift off speed at lower ground speed, shortening take off distance and increasing aoa Landing- headwind lowers ground speed and steepens approach angle, reducing landing distance Cruise- headwind decreases performance by reducing ground speeds, tailwind increases

Question 38

TO/Landing Performance - Weight

Answer 38

Take off- increased weight: Higher liftoff speed Slow acceleration Increased drag & ground friction Longer take off distance Landing: Increased landing distance

Question 39

TO/Landing Performance- Density Altitude

Answer 39

Increased: TO Distance (greater TAS required) True airspeed on approach and landing Landing roll distance Reduced rate of climb

Question 40

Density Altitude

Answer 40

Pressure altitude corrected for nonstandard temperature Vertical distance above sea level in the standard atmosphere at which a given density is found

Question 41

Aircraft performance - Air Density

Answer 41

Density effects- Lift produced by wings Power output of engine Propeller efficiency Drag forces

Question 42

Factors affecting air density

Answer 42

Altitude (higher, less dense, density altitude increases) Temp (warmer, less dense) Humidity (more humid, less)

Question 43

Best glide speed vs min sink rate

Answer 43

Best glide is greatest distance for loss of altitude Best sink maximizes time remains in flight, lowest rate for losing altitude

Question 44

Pressure Altitude

Answer 44

Altitude indicated when altimeter adjusted to 29.92 altitude above standard datum plane