Performance Limitations Flashcards
What are the four forces of flight?
Lift
Weight
Thrust
Drag
What are the primary flight controls?
- Aileron
- Elevator/ Stabilator
- Rudder
What are the secondary flight controls?
- Flaps
- Leading edge devices
- Spoilers
- Trim systems
How is lift created?
- Newtons 3rd law- Airfoils create a downward acceleration of air known as a downwash.
- Bernoulli’s principle- As velocity of a fluid or gas increases, the pressure decreases. This creates low pressure above the wing and high pressure below it, The pressure difference pulls the wing upwards.
Types of drag?
A. Parasite drag- Increases as speed is increases.
1a. Form drag- Anything that sticks out from the aircraft.
2a. Skin friction- Caused by air slowing down as it moves across the surface of the aircraft.
3a. Interference drag- Intersecting airstreams between the fuselage and the wing.
B. Induced Drag- Byproduct of lift, decreases with an increases in airspeed.
What is camber? How can we change it?
- Curvature of the wing
- Can be changed by extending/ retracting flaps or leading edge devices.
What is the angle of incidence?
Angle between the chord line and longitudinal axis.
What is the CG?
CG is the point where the aircraft is balanced or the place where the entire weight is concentrated.
Effects of forward CG?
- Lower cruise speed
- Higher stall speed
- More stable
- Favorable stall recovery
- Difficulty in rotating and rounding out during landing. Also, difficulty in steering can result.
Effects of Aft CG?
- High cruise speed
- Lower stall speed
- Less stable
- Adverse stall recovery
- Shorter arm between CG and control surfaces on the tail makes them less effective.
Forward CG
A nose heavy condition that results in the pilot having to use more back pressure to maintain a level flight attitude.
Aft CG
Less tail down force is required when flying with an aft CG. Less overall drag resulting in faster cruise speed.
What causes a wing to stall?
Anytime the critical AOA is exceeded.
How does temp. change the takeoff distance? Weight? Air density?
1.High temp= less dense air
2. Less dense air exerts less force on airfoils making them less efficient and also deprives the engine of power. Leading to longer take off rolls and decreased climb performance.
3. High weight also leads to longer take off rolls and increased landing distance because it takes more engine power to accelerate a heavy aircraft.
What are the types of airspeed?
- IAS- Indicated airspeed
- CAS- Calibrated airspeed
- TAS- True airspeed
- GS- Ground speed
What are the types of altitude?
- Indicated
- Pressure
- Density
- True
- Absolute
What factors affect air density?
- Heat- warm air expands making it less dense.
- Height- air at higher altitudes is less dense.
- Humidity- A parcel of humid air is less dense because water molecules take up more room and spread out the air molecules.
What is the weight of one gallon 100LL?
6 pounds
What are V-speeds?
- VS0- Stalling speed in the landing configuration
- VS1- Stalling speed in a specified configuring
- Vy- Best rate of climb
- Vx- Best angle of climb
- Vfe- Flaps extended speed
- VA- Design maneuvering speed.
- VNO- Maximum structural cruising speed.
- VNE- Never exceed speed.
Torque
A clockwise spinning prop causes airplane to roll left about the longitudinal axis.
Gyropscopic Precession
A principle of gyroscopes that states when a force is applied to a spinning object, the maximum reaction occurs approximately 90 degrees later in the direction of rotation.
Asymmetrical Thrust
A tendency for an aircraft to yaw to the left due to the descending propeller blade on the right producing more thrust than the ascending blade on the left.
Spiraling Slipstream
Propeller wash strikes the aircraft of the left side of the vertical stabilizer causing left yawing tendency.
Lateral Stability
Resistance to roll
Longitudinal stability
Resistance to pitch
Directional stability
Resistance to yaw
