Performance and Limitations

Question 2

What is aerodynamics?

Answer 2

The study of how air flows around an aircraft and produces forces that enable flight (PHAK Ch. 3).

Question 3

What are the four forces of flight?

Answer 3

Lift (perpendicular to relative wind), weight (vertically downward through CG), thrust (forward from engine/prop), and drag (opposes thrust).

Question 4

In steady, unaccelerated flight, how do the four forces relate?

Answer 4

Lift equals weight and thrust equals drag.

Question 5

What is relative wind?

Answer 5

Airflow opposite the aircraft’s flight path; it changes with climbs, descents, and turns and is rarely horizontal.

Question 6

What is angle of attack (AOA)?

Answer 6

The angle between the wing chord line and relative wind; primary factor determining lift and stall.

Question 7

What happens as AOA increases?

Answer 7

Lift increases until reaching the critical angle; exceeding it causes a stall regardless of airspeed, weight, altitude, or attitude.

Question 8

Can airspeed alone indicate a stall?

Answer 8

No; airspeed is only an indirect indicator of AOA and can be misleading during maneuvering.

Question 9

What factors influence lift?

Answer 9

Air density, airspeed, wing area, and coefficient of lift; AOA is the only factor directly controlled by the pilot.

Question 10

What is induced drag?

Answer 10

Drag caused by lift; increases with higher AOA, greatest during takeoff, climb, and slow flight.

Question 11

What is parasite drag?

Answer 11

Drag from air resistance (form, skin friction, interference); increases with airspeed.

Question 12

What is L/D max?

Answer 12

The point of minimum total drag, corresponding to best glide speed.

Question 13

What is stability in aircraft?

Answer 13

The tendency to return to equilibrium after a disturbance; includes static (initial) and dynamic (over time) stability.

Question 14

How does CG affect stability?

Answer 14

Forward CG increases stability but stall speed and control forces; aft CG decreases stability and increases spin difficulty.

Question 15

What is load factor?

Answer 15

Ratio of lift to weight; increases with bank angle and increases stall speed.

Question 16

What is an accelerated stall?

Answer 16

A stall occurring at higher airspeeds due to increased load factor, such as in steep turns.

Question 17

How do stalls occur?

Answer 17

When airflow separates from the wing due to excessive AOA; can happen in any attitude regardless of airspeed, power, or weight.

Question 18

How do you recover from a stall?

Answer 18

Reduce AOA first, then add power as needed.

Question 19

What is a spin?

Answer 19

An aggravated stall with autorotation; requires both a stall and yaw, with one wing more deeply stalled.

Question 20

What are the phases of a spin?

Answer 20

Entry (stall with yaw), incipient (rotation starts), developed (rotation and descent stabilize), recovery (controls applied to stop rotation).

Question 21

What is the PARE method for spin recovery?

Answer 21

Power idle, Ailerons neutral, Rudder full opposite rotation, Elevator forward; rudder neutralized once rotation stops.

Question 22

What are left-turning tendencies?

Answer 22

Torque (roll opposite prop), P-factor (yaw due to asymmetric thrust), spiraling slipstream (prop wash on tail), gyroscopic precession; most noticeable at high power, low airspeed.

Question 23

What factors affect aircraft performance?

Answer 23

Weight, balance, density altitude, runway conditions, wind, aircraft configuration, and pilot technique (PHAK Ch. 10).

Question 24

How does increased weight affect performance?

Answer 24

Increases stall speed, takeoff and landing distances, reduces climb rate and service ceiling.

Question 25

How does CG affect performance?

Answer 25

Forward CG increases stability but increases takeoff/landing distance; aft CG improves cruise efficiency but decreases stability and spin recovery.

Question 26

What is density altitude?

Answer 26

Pressure altitude corrected for nonstandard temperature; “high, hot, and humid” reduces engine power, prop efficiency, and wing lift.

Question 27

What factors increase takeoff distance?

Answer 27

High density altitude, increased weight, tailwind, uphill slope, soft/contaminated runway, unleaned mixture.

Question 28

How do headwinds and tailwinds affect takeoff?

Answer 28

Headwinds decrease takeoff distance; tailwinds increase takeoff distance and reduce climb performance.

Question 29

What is rate of climb?

Answer 29

Vertical speed in ft/min; depends on excess power (engine power minus level flight power required).

Question 30

What is angle of climb?

Answer 30

Steepness of climb; depends on excess thrust (thrust minus drag).

Question 31

What is Vx?

Answer 31

Best angle of climb speed; maximizes altitude per distance, used for obstacle clearance; Vx increases with altitude.

Question 32

What is Vy?

Answer 32

Best rate of climb speed; maximizes altitude per time; Vy decreases with altitude.

Question 33

How do wind, weight, and configuration affect climb?

Answer 33

Headwinds improve obstacle clearance; tailwinds reduce climb path; heavier weight and extended flaps/gear reduce climb performance.

Question 34

What is cruise performance?

Answer 34

Optimized by proper power, mixture, and altitude; higher altitudes improve true airspeed but reduce available climb.

Question 35

What is range vs endurance?

Answer 35

Range = max distance on given fuel; endurance = max time airborne. Max range at L/D max; max endurance at minimum power required.

Question 36

What factors affect landing distance?

Answer 36

High density altitude, increased weight, tailwind, downhill slope, contaminated runway; proper approach speed and flaps reduce distance.

Question 37

What are common performance errors?

Answer 37

Failing to calculate density altitude, underestimating tailwind, overloading aircraft, not leaning mixture at high DA, assuming sea-level performance at high-elevation airports.

Question 38

What is calculated vs actual performance?

Answer 38

Calculated = ideal performance from POH charts; actual = real-world performance, usually worse due to environment, pilot technique, and aircraft condition.

Question 39

How do atmospheric conditions affect performance?

Answer 39

Air density affects engine power, lift, and prop efficiency; reduced density increases takeoff distance and reduces climb.

Question 40

What factors determine air density?

Answer 40

Temperature, pressure, humidity.

Question 41

How does high density altitude affect performance?

Answer 41

Reduces engine power, propeller efficiency, wing lift; increases takeoff distance, reduces climb, increases true airspeed for given IAS.

Question 42

How does wind affect performance?

Answer 42

Headwinds reduce takeoff/landing distance; tailwinds increase distance; gusts complicate control.

Question 43

What is atmospheric stability?

Answer 43

Stable = smooth flight, poor vertical mixing; unstable = turbulence, strong updrafts/downdrafts, convective activity.

Question 44

How does pilot technique affect performance?

Answer 44

Poor airspeed control, mixture management, or configuration significantly degrades real-world performance; FAA charts assume perfect technique.

Question 45

Key takeoff technique tips?

Answer 45

Proper lineup, full power application, directional control, correct rotation airspeed; over-rotation increases drag and slows climb.

Question 46

Key climb technique tips?

Answer 46

Maintain Vx for obstacles, Vy for rate; adjust speed for altitude; retract flaps/gear promptly.

Question 47

Key landing technique tips?

Answer 47

Stabilized approach, correct airspeed, proper flare; excessive speed increases rollout.

Question 48

What human factors affect technique?

Answer 48

Fatigue, stress, distractions; poor technique compounds environmental challenges.

Question 49

How does aircraft configuration affect performance?

Answer 49

Flaps, gear, mixture, trim, and power settings directly affect takeoff, climb, and landing; improper configuration reduces performance.

Question 50

Flap effects?

Answer 50

Increase lift at low speed; improper selection increases drag, reduces climb gradient.

Question 51

Gear effects?

Answer 51

Extended gear increases drag; retract promptly after takeoff.

Question 52

Mixture effects?

Answer 52

Lean for max power at high DA; full-rich reduces acceleration and climb.

Question 53

Trim effects?

Answer 53

Proper trim reduces control forces; mis-trim increases pilot workload.

Question 54

Common configuration mistakes?

Answer 54

Leaving flaps/gear down, unleaned mixture, incorrect trim or power settings.

Question 55

How does the airport environment affect performance?

Answer 55

Runway length, slope, surface, obstacles, terrain, wind, and density altitude all directly affect takeoff, climb, approach, and landing.

Question 56

Runway length/slope/surface effects?

Answer 56

Short or uphill runways increase takeoff distance; soft/contaminated surfaces reduce acceleration; downhill reduces takeoff but increases landing distance.

Question 57

Obstacle and terrain effects?

Answer 57

Require 50-ft clearance and Vx planning; terrain-aware climb planning needed.

Question 58

Wind and density altitude effects?

Answer 58

Headwinds improve takeoff/climb; tailwinds reduce climb; high density altitude reduces power, lift, prop efficiency.

Question 59

Why is weight and balance critical?

Answer 59

Directly affects stability, control, and performance; improper weight or CG can increase stall/spin risk and reduce climb.

Question 60

W& B Legal requirements?

Answer 60

FAR 91.103 and 91.9 require pilots to operate within approved limits.

Question 61

How does CG affect performance?

Answer 61

Forward CG = more stable, higher stall speed; aft CG = less stable, easier spins.

Question 62

How does fuel arm affect CG?

Answer 62

Fuel location shifts CG; as fuel burns, CG changes, must remain within limits throughout flight.

Question 63

How do cargo/passenger loads affect CG?

Answer 63

Improper distribution can make aircraft nose- or tail-heavy, reducing control and increasing stall/spin risk.

Question 64

Effects of overweight or misbalanced aircraft?

Answer 64

Longer takeoff/landing, reduced climb, higher stall speed, reduced maneuverability; FAA cites weight/CG errors as leading accident cause.

Question 65

Phases of a spin?

Answer 65

Entry phase: Aircraft stalls with yaw present Incipient phase: Rotation begins but is not fully stabilized Developed phase: Rotation, airspeed, and descent rate stabilize Recovery phase: Correct control inputs stop rotation and break the stall

Question 66

Forward CG characterisics?

Answer 66

A forward CG increases longitudinal stability, makes the aircraft nose-heavy, increases stall speed, requires higher control forces (especially for pitch), increases takeoff and landing distances, reduces climb performance, and can make flare and rotation during takeoff more difficult

Question 67

Aft CG Characteristics?

Answer 67

An aft CG decreases longitudinal stability, makes the aircraft tail-heavy, reduces pitch control authority, lowers stall speed but increases stall/spin susceptibility, can result in flatter spins, delays spin recovery, improves cruise efficiency, and generally makes the aircraft more sensitive to control inputs

Question 68

Forward CG versus Aft CG?

Answer 68

forward CG = safer; aft CG = more efficient but riskier.