Chapter 1: Basic Aerodynamics Flashcards
(TP-Terms) The term “angle of attack” is defined as the angle
between the wing chord line and the relative wind
(TP-Terms) The angle between the chord line of an airfoil and the relative wind is know as the angle of
attack
(TP-Terms) The angle of attack is defined as the angle between the chord line of an airfoil and the
direction of the relative wind
(TP-Terms) The angle of attack at which an airfoil stalls will
remain the same regardless of gross weight(the indicated airspeed at which stall occurs will be determined by weight and load factor, but the stall angle of attack is the same: 18-20 degrees)
(TP-Terms) What is the effect of advancing the throttle in flight
Airspeed will remain relatively constant but the aircraft will climb.
(TP-Axis/Four Forces) What does Bernoulli’s principle state?
Air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface (which results in lift)
(TP-Axis/Four Forces) What is the relationship of lift, drag, thrust and weight?
Lift equals weight and thrust equals drag.
(TP-Axis/Four Forces) When are the four forces that act on an airplane in equilibrium?
During unaccelerated flight
(TP-Axis/Four Forces) The best speed to use for a glide is one that will result in the greatest glide distance for a given amount of
altitude.(the best glide speed corresponds to an angle of attack resulting in the least drag on the airplane and giving the best lift-drag ratio. (L/Dmax)
(TP-Axis/Four Forces) Climb performance depends upon the
reserve power or thrust.
(TP-Axis/Four Forces) The horizontal dashed line from point C to point E represents the
positive limit load factor.
(TP-Axis/Four Forces) The vertical dashed line from point E to point F is represented on the airspeed indicator by the
upper limit of the yellow arc.
(TP-Stability) An airplane said to be inherently stabil will
Require less effor to control
(TP-Stability) What determines the longitudinal stability of an airplane?
The location of the CG with respect to the center of lift
(CG aft of the center of lift will result in an undesirable pitch up moment during flight, an airplane with the center of gravity forward of the center of lift will pitch down when powder is reduced. This will increase the airspeed and the downward for of the elevators. The increased downward force on the elevators will bring the nose up, providing positive stability. The farther forward the CG airplane, the more stable.)
(TP-Stability)What causes the airplane (except a t-tail) to pitch nosedown when the power is reduced and the controls are not adjusted?
The CG shifts forward when thrust and drag are reduced.
(TP-Stability)The airplane has been loaded in such a manner the the CG is located aft of the CG limit. One undesirable flight characteristic a pilot might experience with this airplane would be.
difficulty recovering from a stalled position.
(TP-Stability)Loading an airplane to themes aft CG will cause the airplane to be
less stable at all speeds
(TP-Stability)Changes in the center of pressure of a wing affects the aircraft’s
aerodynamic balance and controllability
(TP-Turns/Loads/LF)How do you calculate how much weight an airplane’s structure can support?
Multiply aircraft weight (lbs) by the load factor (G’s).
(TP-Turns/Loads/LF)The amount of excess load that can be imposed on the wing of an airplane depends upon the
speed of the airplane
(TP-Turns/Loads/LF)Which basic flight maneuver increases the load factor on an airplane as compared to straight-and-level flight?
Turns
(TP-Turns/Loads/LF)What force makes an airplane turn?
The horizontal component of lift
(TP-Turns/Loads/LF)During an approach to a stall, an increased load factor will cause the airplane to
stall at a higher airspeed
(Stall speed increases in proportion to the square root of the load factor. Thus, with a load factor of 4, an aircraft will stall at a speed which is double the normal stall speed.)
(TP-Maneuvers) What are the four flight fundamentals involved in maneuvering an aircraft?
Straight and level flight, turns, climbs, and descents
(TP-Maneuvers) Flying the rectangular course, when would the aircraft be turned less than 90 degrees?
Corners 1 and 4
At corner 1, the airplane turns into a heading that is crabbed into the wind, which makes the turn less than 90 degrees. At corner 4 the airplane is crabbed into the wind when the turn is started, and then the turn will be less than 90 degrees.
(TP-Maneuvers) While practicing S turns, a consistently smaller half-circle is made on one side of the road than on the other, and this turn is not completed before crossing the road or reference line. This would most likely occur in a turn
4-5-6 because the bank is increased too rapidly during the early part of the turn.
(In the half of an S-turn labeled 4-5-6 the bank should begin shallow and increase in steepness as the airplane turns crosswind and becomes steepest at point 6 where the turn is downwind. If the turn at point 4 is started with too steep a bank angle, the bank will increase too rapidly, and the upwind half of the S will be smaller than the downwind half. The turn will not be completed by the time the airplane is over the reference line.
(TP-Maneuvers) If an emergency situation requires a downwind landing, pilots should expect a faster
groundspeed at touchdown, a longer ground roll, and the likelihood of overshooting the desired touchdown point.
(TP-Maneuvers) When executing an emergency approach to land in a single-engine airplane, it is important to maintain a constant glide speed because variations in glide speed.
nullify all attempts at accuracy in judgement of gliding distance and landing spot.
(TP-Stalls/Spins) As altitude increases, the indicated airspeed at which a given airplane stalls in a particular configuration will
remain the same regardless of altitude
(TP-Stalls/Spins) The direct cause of every stall is excessive
angle of attack
(TP-Stalls/Spins) In what flight condition must an aircraft be placed in order to spin?
Stalled
(TP-Stalls/Spins) During a spin to the left, which wing(s) is/are stalled?
Both wings are stalled (one more than the other)
(TP-Stalls/Spins) The angle of attack at which an airplane wing stalls will
Remain the same regardless of gross weight.
(The indicated airspeed at which a stall occurs will be determined by weight and load factor, but the stall angle of attack is always the same.)
(TP-Flaps) One of the main functions of flaps during an approach and landing is to
increase the angle of descent without increasing airspeed
(TP-Flaps) What is one purpose of wing flaps?
To enable the pilot of make steeper approaches to a landing without increasing the airspeed
(Flaps increase drag, allowing the pilot to make steeper approaches without increasing airspeed)
(TP-Ground Effect) Ground Effect is most likely to result in what problem?
Becoming airborne before reaching recommended take off speed
(TP-Ground Effect) What is ground effect?
The result of the interference of the surface of the Earth with the airflow patterns about an airplane
(TP-Ground Effect) Floating caused by the phenomenon of ground effect will be most realized during an approach to land when at
less than the length of the wingspan above the surface.
(TP-Ground Effect) What must a pilot be aware of as a result of ground effect?
induced drag decreases; therefore any excess speed at point of flare may cause considerable floating
(TP-Ground Effect) Which is a result of the phenomenon of ground effect?
The angle of attack generating lift is increased
(TP-Ground Effect) [Figure 46] The airspeed range to avoid while flying in ground effect is
40 MPH and above
An airplane leaving ground effect during take off will
experience an increase in induced drag and a decrease in performance
(An airplane leaving ground effect will:
- Require an increase in angle of attack to maintain the same lift coefficient
- Experience an increase in induced drag and thrust required
- Experience a decrease in stability and a nose-up change in moments
- Produce a reduction in static source pressure and an increase in indicated airspeed. )
(TP-Wake Turbulence) When landing behind a large aircraft, which procedure should be followed for vortex avoidance?
Stay above its final approach flightpath all the way to touchdown.
(TP-Wake Turbulence) How does the wake turbulence vote circulate around each wingtip?
Outward, upward, and around each tip
(TP-Wake Turbulence) When taking off or landing at an airport where heavy aircraft are operating, one should be particularly alert to the hazards of wingtip vortices because this turbulence tends to
sink into the flightpath of aircraft operating below the aircraft generating the turbulence
(TP-Wake Turbulence) Wingtip vortices are created only when an aircraft is
developing lift
(TP-Wake Turbulence) The greatest vortex strength occurs when generating aircraft is
heavy, clean, and slow
(TP-Wake Turbulence) Wingtip vortices created by large aircraft tend to
sink below the aircraft generating turbulence
(TP-Wake Turbulence) The wind condition that requires maximum caution when avoiding wake turbulence on landing is
light, quartering tailwind
(TP-Wake Turbulence) When landing behind a large aircraft, the pilot should avoid wake turbulence by staying
above the large aircrafts final approach path and landing beyond the large aircrafts touchdown point
(TP-Wake Turbulence) When departing behind a heavy aircraft, the pilot should avoid wake turbulence by maneuvering the aircraft
above and upwind from the heavy aircraft
(TP-Wake Turbulence) What wind condition prolongs the hazards of wake turbulence on a landing runway for the longest period of time?
Light quartering tailwind
(TP-Wake Turbulence) A go-around from a poor landing approach
is preferable to last minute attempt to prevent a bad landing
