Straight and Level Flashcards
Straight and level means…
S&L: Being kept laterally level in a state of balance whilst maintaining a constant height.
Forces need to be equilibrium, lift = weight and thrust = drag.
Weight and Lift
Weight: Sum of the mass, fuels, gadgets, aeroplane and us.
Lift: Bernoulli theorised that in steady streamlined airflow, the total sum of the static and dynamic pressure will remain constant. (TP = SP + DP).
ISA
ISA = International standard atmosphere. 15 degrees and 1013 HPA 14.7 PSI (tire pressure), those are the averages in atmosphere. Hecta pascals
dYNAMIC AND STATIC PRESSURE
Static pressure: Non-moving part.
Dynamic Pressure: The moving component of air.
Ventry Tube: Increase in dynamic pressure.
As airspeed increase, both static and dynamic decrease.
Air going over wing, equals fast speed low pressure. More curvature (camber).
Air going under wing high pressure slow speed.
Lift formula
Lift Formula: LIFT = Coefficient of lift ½ p V^2 S
Cl = AoA and Camber
P = Air density aka row.
Denser air better lift, etc.
V = Velocity, indicator of speed.
S = Wing surface area.
Mean camber line: Average between the wings.
Centre of pressure: Sum of lift and drag.
L = ?
L = Aoa x AirSpeed
AoA must increase if airspeed decrease. Pilots lift formula.
Drag
Types of Drag: Induced and parasite drag.
Induced: Can’t create lift without drag. Pressures want to equalise.
Air on top is moving inwards opposite at the bottom of wing.
Vortices: Greatest at the end of the wings.
Biggest factor of induced is AOA.
As AOA increased local airflow goes up further and further.
Wake Turbulence: Flying through those vortices creates turbulent airflow.
Ground Effect: 1.3x stall speed.
Power
Thrust curve and drag curve are the same. To stay level.
Force = mass x acceleration.
Power + Attitude = Performance.
Attitude: Nose relative to the horizon.
Fast Power = 5000rpm
Slowing Down = 4500rpm – Attitude = 3-4 fingers depending – Performance = 80
PAST: power, attitude, speed, and trim.
Entering is PAST.
CHAT: Change, hold, adjust and trim.
Maintaining: ALAP, attitude, look out, attitude, performance.
Stability
Stability: The inbuilt tendency of an object once disturbed to return to its original condition, but not necessarily position.
Nuetral Stability: Changes position and holds it.
Unstable: Knock the ball off and it continues to go away forever and ever. Doesn’t come back to its original position.
Stable: Comes back to original position. Might not return to its original direction/position.
Longitudinal Stability: Stability of the aircraft regarding its lift and weight.
Tail Down Force: Negative angle of incident. Creates lift in downwards direction. L = Weight + TDF.
Lateral Stability: Pendulosity. Dihedral.
Directional Stability: Stability about the normal axis (z-axis).
Alcohol
Rule For Alcohol:
8 hours before last drink or 0.02 BAL.
Parasite Drags
Parasite: All these drags. More prevalent at higher airspeeds.
Form Drag: caused by the separation of the boundary layer from a surface and the wake created by that separation.
Cooling Drag: cooling the engine of a propeller
Interference Drag: generated by the mixing of airflow streamlines between airframe components such as the wing and the fuselage
