Unit 1: Airplanes & Aerodynamics Flashcards
What are the three flight controls, their movement, axes of rotation, and stability?
- Aileron : Roll : Longitudinal: Lateral
- Elevator/Stabilator : Pitch : Lateral : Longitudinal
- Rudder : Yaw : Vertical : Directional
What are the secondary flight controls?
Flaps: too make steeper approaches (increase angle of descent) to a landing without increasing the airspeed
Trim: help maintain constant pressure on flight controls
Spoilers: reduce lift and increase drag
What are the four aerodynamic forces?
Lift, Weight, Thrust, Drag
When are the four aerodynamic forces at equilibrium?
Unaccelerated Flight
Lift = Weight
Thrust = Drag
Bernoulli’s Principle
Internal pressure of a fluid decreases at points where the speed of the fluid increases
Aviation: Air traveling faster over the curved upper surface of an airfoil caused lower pressure on the top surface
AOA
Angle of Attack is the angle between the chord line and direction relative wind
Chord Line
Imaginary straight line from leading edge to trailing edge
What are the factors that affect AOA to cause an airplane to stall?
If i exceeds the critical AOA. The wing stall remains contact REGARDLESS of weight, airspeed, altitude, temp
What causes an airplane to spin
When one wing is less stalled than the other wing. It will descend in a corkscrew path.
Ground Effect
Interference of ground/water surface with the airflow patterns about an airplane
- less than one wingspan above the ground
What component makes an airplane turn
Horizontal component of lift
Inherently stable airplane
Returns to its OG position after being disturbed. Requires less effort to control.
What determines these longitudinal stability of an airplane
Location of CG with respect to center of lift/pressure
What happens if there is a change in the center of pressure in wing?
Affects the aerodynamic balance & control
What happens to airplanes when power is reduced and controls are not adjusted
The nose pitches down due to downwash/reduced effectiveness on elevators from reduced propeller slipstream. EXPECT TTAIL AIRPLANES
What happens when CG is located at or rear aft CG limit
Inability to recover from stall conditions, less stable at all airspeeds, increased likelihood of inadvertent stress
What are the 4 types of Left Turning Tendencies
- Torque Effect: Low airspeed, High AOA, High Power
- P-Factor: descending right side of propeller has a higher AOA as upward moving blade on the left
- High Speed Rotation: creates a corkscrew/spiraling rotation to the slipstream (highest on high propeller & low forward speed)
- Gyroscopic Precession: when force is applied to a spinning object, the max. Reaction occurs about 90 degrees later in the direction of rotation (which causes a pitching & yawing moment) - usually in a tail wheel plane
Load Factor
Additional weight carried by the wings due to weight plus the centrifugal force
- increase LF can cause stalling at higher airspeed
- LF increases when bank increases
Based on Figure 72. Velocity vs. G-Loads what does each letter represent.
A - J: Normal Stall Speed Vs
C - H: Maneuvering Speed Va
D - G: Maximum structural cruising speed Vno
E - F: Never Exceed Speed Vne
C - E: Positive Limit Load Factor
I - G & G - F: Negative Limit Load Factor
What happens during ground effect and getting out of it?
While in GF induced drag decreases, floating may occur or airplane becomes airborne before reaching sufficient speed.
While getting out of GF, induced drag increases and a decrease in performance
What happens when you advance the throttle in flight
Ground speed and AOA increases
How to determine LF
Weight x LF(that corresponds with bank angle)
The amount of excess load that can be imposed on the wing of an aircraft depends on ?
Airspeed
Which basic flight maneuver increases the load factor compared to straight and level?
Turns
During an approach to stall, an increased load factor will cause the aircraft to
Stall at a higher airspeed
Limit load factor
Ratio of max sustainable load to the gross weight of the airplane
