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