Chapter 2 Aerodynamics Flashcards
What causes an airplane (except a T-tail) to pitch nose down when power is reduced and controls are not adjusted?
The downwash on the elevators from the propeller slipstream is reduced and elevator effectiveness is reduced.
The critical angle of attack at which the wing stalls ___
Never changes, regardless of airplane weight
As the airplane become airborne and flies out of ground effect, the wing’s downwash…
Increases
At a relatively slow speed ( such as during takeoff), the wing’s engineered curve isn’t capable of curving or deflecting enough air in which direction to produce the necessary lift for flight?
Downward
A good reason to use maximum endurance speed is..
to minimize fuel consumption, e.g., while waiting for the weather to clear
Wings are expressly built to plow through air molecules separating them either above or below while offering little resistance in the ___ direction
Horizontal
Since high pressure always moves toward low pressure, the wing ( which just happens to be in the way) is pushed ___ in the process.
Upward
The minimum forward speed of the airplane is called the ____ speed
Stall
The most important rule to remember int he event of a power failure after becoming airborne is to
Immediately establish the proper gliding attitude and airspeed
Once the airplane is no longer stalled it should be put back in the desired attitude while making sure you don’t ___ again
Stall
When operating in ground effect what happens to induced drag?
Induced drag decreases; therefore, any excess speed at the point of flare may cause considerable floating
Increasing the airplane’s weight will not affect the ___ of attack at which the airplane stalls
Angle
Drag is the airplane’s natural response to an object’s movement through the ___
Air
With respect to the certification of aircraft, which are categories of aircraft?
Normal, Utility, Acrobatic
Wind deflected downward by the airfoil creates a/an ___ movement of the wing.
Upward
When induced and parasite drag curves are added together, they produce the ___ curve
Total Drag
If an airplane stalls, the first step in recovering is to decrease the angle of attack by moving the elevator control ___ or releasing ___ on the elevator control
forward, back pressure
As the angle of attack exceeds approximately 18 degrees the air molecules flowing over the wing don’t negotiate the turn very well. When this happens, they spin off or burble into the free air, no longer providing a uniform, high-velocity, laminar airflow over the wing. The wing ___
Stalls
An important principle to understand when dealing with angle of attack is that the nose (therefore the wing) can be pointed on an incline that’s ___ the actual climb path.
Different from
Wingtip vortex action increases with an increase in
Angle of attack
What’s the reason for putting flaps on airplanes
To create the lift necessary to maintain flight at slower airspeeds
When the control wheel (or stick) is turned to the right or left, the ailerons simultaneously move in ___.
different directions
Wing tip vortices rotate which way about the wingtip?
Outward, upward and inward
P-factor is more likely to cause the airplane to yaw to the left…
at high angles of attack
Because of the larger angle of attack and greater curvature, flaps provide you with ___ lift for a given airspeed
More
What is an important airspeed limitation that is not color coded on airspeed indicators?
Maneuvering speed
Induced drag is resistance to motion induced by the wing turning some of its ___ into ___
Lift, Drag
To prevent structural damage to the airplane during turbulence,
Maintain flight at or below the airplane’s design maneuvering speed.
The four forces acting on an airplane are
Lift, weight, thrust, drag
In what flight condition must an aircraft be placed in order to spin?
Stalled
Parasite drag is caused by …
friction of protruding airplane parts with the air
As the airplane speeds up, induced drag ___ while parasite drag
Decreases, Increases
The beginning of the white arc is known as the…
Power-off, full-flap stalling speed
Ground effect results from a/an ___ in induced drag
Decrease
The angle of attack at which an airplane wing stalls will ___
remain the same regardless of gross weight
Which V-speed represents maneuvering speed?
Va
You can determine an airplane’s best glide speed
by referring to the POH or the owner’s manual.
Recalling that effective lift always acts ___ to the relative wind, when the angle of attack increases, the total lift force tilts ___ slightly.
Perpendicular, rearward
High velocity airflow over the wing causes a slight decrease in pressure on the wing’s upper surface. In other words, the pressure on ___ the wing is now ___ than the pressure on bottom of the wing.
Top, less
Airplanes ___ about their lateral axix
Pitch
Upon encountering severe turbulence, which flight condition should the pilot attempt to maintain?
Level flight attitude
Induced drag is
the rearward pull of the total lifting force.
High pressure on the botoom of the wing causes air molecules to move sideways (toward the wingtip) in the direction of ___ pressure on top of the wing. This action is responsible for the creation of ___
Lower, wingtip vortices
The sum of the parasite and induced drag curves reveals a point on the total drag curve where drag is at a minimum. the speed associated with this point is
The airplane’s maximum power-off glide range
What is one purpose of wing flaps?
To enable the pilot to make steeper approaches to a landing without increasing the airspeed
Why is frost considered hazardous to flight?
Frost spoils the smooth flow of air over the wings, thereby decreasing lifting capability.
Frost on the airfoil ___ the airplane’s stalling speed
Increases
When are the four forces that act on an airplane in equilibrium?
During unaccelerated flight
The purpose of ailerons is to ___ the airplane in the direction you desire to turn
Bank
Relative wind is ___ which way the airplane’s nose is pointed.
Independent of
