Ch 3 Aerodynamics Flashcards
What increases the lift coefficient?
Increased angle of attack and wing shape
What is angle of attack?
The angle between the wing chord and the relative wind
What all contributes to total lift?
The product of the lift coefficient, the square of velocity, half of air density, and wing surface area.
Where is the center of lift?
Aft of the center of gravity, counteracted by the tail
What propels a glider forward without an engine?
Gravity (weight)
What determines what is the maximum glide ratio (best glide speed)?
The point at which the combined parasite and induced drag is at its lowest
What is aspect ratio?
Wing span divided by wing chord
What are winglets?
Wingtip devices that reduce induced drag.
What is wing washout?
Twisting of the wing to have higher AOA at the root than the tip
What is static stability?
The tendency of a plane to return to its original orientation.
What is dynamic stability?
The tendency of oscillations to dampen over time.
How does too aft of CG affect stability?
Decreases dynamic stability
How does too forward a CG affect stability?
Increased tendency to pitch down
What is dihedral?
The upward lateral angle of the wings. This adds lateral stability.
What is flutter?
Rapid oscillation of the wing due to excessive airspeed.
What is pilot induced oscillation?
Over correction of controls leading to increased oscillation and loss of control.
How do you recover from oscillations?
By easing flight control pressure sooner after positive response
Which instruments become disrupted during a slip?
The airspeed indicator becomes unreliable.
What is a forward slip?
Used to descend more rapidly along the same ground track.
What is a side slip?
Used to counteract a crosswind
Why does a stall occur?
Excessive angle of attack
What should a pilot do in gusty conditions?
Increase IAS by half the gust speed
Why do we maintain a constant glide speed?
To allow accurate landings. Changes in glide speed making judging accurate landings impossible.
What determines longitudinal stability?
CG relative to center of lift
