Performance and Limitations Flashcards
Define: Angle of Incidence
The angle formed by the longitudinal axis of the airplane and the chord line of the wing.
The angle at which the wing is attached to the fuselage.
Define: Relative Wind
The direction of the airflow with respect to the wing.
Define: Bernoulli’s Principle
The pressure of a fluid decreases as the speed of the fluid increases.
Ex: Lower pressure on top of the wing where the speed is increased.
Define: Torque Effect
The propeller is moving in one direction so an equal force is trying to rotate the airplane in the opposite direction.
Define: Centrifugal Force
The “equal and opposite reaction” of the airplane to change in direction.
Define: Load Factor
The actual load supported by the wings divided by the airplane’s total weight.
Also expressed as ratio of a given load to the pull of gravity.
Ex: 3g’s = weight of the airplane is 1 and the load factor is 3x that load.
Why is the Load Factor important?
It is dangerous to overload the aircraft structure.
An increased load factor increases stalling speed.
What is the Maximum Safe Load Factor? (Limit LF)
+3.8 to -1.52
Define: Maneuvering Speed
The maximum speed at which abrupt control movement can be applied.
What are the effects on maneuvering speed with an increase or decrease in weight?
Va speed increases with an increase in weight and decreases with a decrease in weight.
What causes a stall?
Excessive Angle of Attack
What causes a spin?
Exceeding the Critical AOA while uncoordinated.
When are spins most likely to occur?
Engine failure on takeoff/climbout Cross controlled base to final Engine failure on approach to land Go-around with full nose-up trim Go-around with improper flap retraction
Define: Empty Weight
All fixed items in and on the aircraft
Also includes:
-unusable fuel/oil
-hydraulic fluid
Define: Gross Weight
The maximum allowable weight of both the airframe and its contents
Define: Useful Load
The weight of:
- Pilot and passengers
- Baggage
- Usable fuel
- Drainable oil
What effects does a forward CG have?
Higher stalling speed
Slower cruise speed
More stable
Greater elevator pressure required
What effects does an aft CG have?
Lower stall speed
Higher cruise speed
Less stable
What factors affect the performance of an aircraft during takeoff and landing?
Air density Surface wind Surface Slope of the runway Weight of the aircraft
What factors affect density altitude?
Altitude
Temperature
Humidity
How to recover from a spin?
P - power idle
A - ailerons neutral
R - rudder opposite direction
E - elevator pitch down (release back pressure)
Procedure for engine failure?
C - Carb heat ON
A - Airspeed to best glide speed
B - Best place to land
C - Checklist
What causes adverse yaw?
Right Turn Left aileron down -AOA increases, increasing lift and drag Right aileron up -AOA decreases, decreasing lift and drag Prop moves to the lift because of the faster right wing, creating an undesired veering (adverse yaw)
Define: Ground Effect
Reduction of induced drag near the surface. Earth’s surface alters the airflow pattern around the aircraft. Improved aircraft performance*
