Principles of Flight Flashcards
What is the name for the initial tendency of an aircraft to develop forces that further remove the aircraft from its original position when disturbed from a condition of steady flight?
Negative static stability
During the entry to a right turn, the nose of the aircraft swings to the left before it follows into the right turn. What kind of turn entry is this and how is it corrected?
This is a slipping turn, which is corrected by more right rudder pressure as the turn is initiated.
What is the name for the initial tendency of an aircraft to develop forces that return the aircraft from its original position when disturbed from a condition of steady flight?
Positive static stability
What kind of oscillations are the result of negative dynamic stability and positive static stability in an aircraft?
divergent oscillations
What kind of oscillations are the result of positive dynamic stability and positive static stability in an aircraft?
convergent oscillations
What is it called when the aircraft experiences airspeed increases and decreases as it works to maintain a constant angle of attack for a given trim?
Phugoid Oscillations
What happens to the vertical component of lift and the sink rate as the angle of bank is increased?
The vertical component of lift decreases and sink rate increases.
What is the purpose of wing dihedral angle?
To increase lateral stability.
During flight with zero angle of attack what can be said about the pressure along the upper surface of the wing?
It is less than atmospheric pressure.
Which is the critical engine on most light multi engine planes with clockwise rotating propellers?
The left engine, because the resultant thrust (due to p-factor) of the running right engine acts with a much greater arm and creates stronger yaw to the left.
If the center of gravity of an aircraft is moved from the aft limit to beyond the forward limit, how will it affect the cruising and stalling speed? Why?
The cruising speed will decrease in the stalling speed will increase. The tail has to generate more downward force to balance the heavier nose and the wings must fly at a higher angle of attack to produce more lift to counteract that force.
Why do you roll level before recovering from a nose low unusual attitude?
To minimize the increased load factor to just what is needed to raise the nose. Also, to avoid tightening a spiral dive.
Why don’t you roll level before recovering from a nose high unusual attitude?
The additional horizontal component of lift helps reduce negative forces on the airframe in the pushover.
How is stall speed related to load factor?
Stall speed increases in proportion to the load factor.
What kind of oscillations are the result of neutral dynamic stability and positive static stability in an aircraft?
continuous oscillations
What kind of a turn produces more centrifugal force than banking force?
A skidding turn.
Which wing drops when a cross controlled stall or skidding turn becomes a spin? Why?
The inside wing drops because it is more stalled due to being at a higher angle of attack, blanketed by the fuselage and subject to spanwise flow that further reduces lift.
Which wing drops when a slipping turn progresses to a stall? Why?
In a slipping turn, the outside wing is at a higher angle of attack somewhat blanketed by the fuselage, so it stalls first.
Explain a slipping turn.
In a slipping turn, not enough rudder is used to counter the adverse yaw created by the lowered elevator and as a result the rate of turn is less than required for the angle of bank. The ball is on the inside of the turn because the centriputal force is greater than the centrifugal force.
What is a coordinated turn?
A coordinated turn is one in which the rate of turn is matched to the bank angle, which causes the nose of the aircraft to be directly into the relative wind throughout the turn.
How does the inclinometer in a turn coordinator work?
In a coordinated turn, the centripital force (horizontal component of lift) and the centrifugal force are equal which holds the ball balanced in the middle opposite the lift vector. In a slipping turn, the centripital force is greater than the centrifugal force, which pulls the ball to the inside of the turn. In a skidding turn, the centrifugal force is greater than the centripital force, which pulls the ball to the outside of the turn.
What are the forces of flight?
Lift, weight, thrust and drag.
What is lift?
Lift is the force that acts upward, perpendicular to the relative wind as a result of airflow passing over the wing.
What is drag?
Drag is the force that opposes thust. It is generated by the resistance of the aircraft and its parts moving through the air.
