Aerodynamics Flashcards
An increased load factor will cause the airplane to stall at a ______ ______
Higher Airspeed
The upper limit of the green arc represents
The maximum structural cruising speed
What does Vno mean?
“No” go there. Maximum structural cruising speed. Beginning of the yellow arc, or caution range. Theoretically, a brand-new aircraft can withstand the FAA’s 50 fps gust at this speed. Unfortunately, the pilot has no way of measuring gust intensity.
What does CG mean?
Center of Gravity
What does Vy mean?
Best rate-of-climb speed. Delivers the greatest gain in altitude in the shortest time. Flaps and gear up. Decreases as weight is reduced, and decreases with altitude. Lift-to-drag ratio is usually at its maximum at this speed, so it can also be used as a good ballpark figure for best glide speed or maximum-endurance speed for holding.
What does Vx mean?
Best angle-of-climb speed. Delivers the greatest gain of altitude in the shortest possible horizontal distance. The speed given in the flight manual is good only at sea level, at max gross weight and with flaps in takeoff position. VX increases with altitude (about ½ knot per 1,000 feet) and usually decreases with a reduction of weight. It will take more time to gain altitude at VX because of the slower speed, but the goal is to gain the most altitude in the shortest horizontal distance.
What does Vfe mean?
Maximum flap-extended speed. Top of white arc. The highest speed permissible with wing flaps in a prescribed extended position. Many aircraft allow the use of approach flaps at speeds higher than VFE. Positive load for Normal category airplanes is usually reduced from 3.8 Gs to 2 Gs with the flaps down, and negative load is reduced from minus 1.52 Gs to zero. The purpose of flaps during landing is to enable steeper approaches without increasing the airspeed.
What does Vle mean?
Maximum landing gear extended speed. Maximum speed at which an airplane can be safely flown with the landing gear extended.
What does Va mean?
Design maneuvering speed. The highest safe airspeed for abrupt control deflection or for operation in turbulence or severe gusts. It does not allow for multiple large control inputs. If only one speed is published it is usually determined at max landing weight. This speed decreases as weight decreases.
Formula for determining VA at less than max landing weight: VA2 equals VA multiplied by current weight divided by max landing weight.
What does Vso mean?
Stall speed in landing configuration. Lower limit of white arc. Stalling speed or the minimum steady flight speed at which the airplane is controllable in landing configuration: engines at idle, props in low pitch, usually full wing flaps, cowl flaps closed, CG at maximum forward limit (i.e., most unfavorable CG) and max gross landing weight. Maximum allowable VSO for single-engine aircraft and many light twins is 61 knots (remember, “stuff out”).
Additional weight carried by the wings divided by the weight of the aircraft
Load Factor
The location of the CG with respect to the center of lift determines the ______ stability of an airplane
Longitudinal
The angle of attack at which an airplane wing stalls will remain ______ ______ regardless of gross weight.
The same
The amount of excess load that can be imposed on the wing of an airplane depends upon the ______ of the airplane
Speed
The upper limit of the yellow arch is the maximum speed at which the airplane can be operated in _____ _____
Smooth air
When not changing speed or direction, you are in ______
Unaccelerated Flight
when Thrust = Drag & Lift = Weight during unaccelerated flight it’s in
Equilibrium
Air traveling faster over curved upper surface causes _____ _____ on the top surface
Lower Pressure
Line created from the trailing edge of the wing to the leading ledge
Chord Line
Angle between chord line and relative wind
Angle of Attack
As you go to higher altitudes the air gets _____ or ___ _____ because air molecules are spaced _____ which is what airplanes have to move faster at higher altitudes
Thinner or Less Dense / Further apart
Stall speed is the same at ______ altitudes
any
A spin to the right or left what wing is stalled
both
Flaps increase ______ but mostly increase _____
lift / drag
What are the purpose of Flaps
increase descent angle without increase in airspeed
Vertical Axis controls
yaw controlled by the rudders
Longitudinal Axis controls
roll controlled by the ailerons
Horizontal Axis controls
pitch controlled by the elevators
Longitudinal stability means
pitch stability
Longitudinal stability is determined by
the location of center of gravity in relation to the center of lift
what happens if you load the airplane to the most AFT CG limit
it will be less stable at all speeds
When you change the angle of attack that changes the
center of pressure which affects the aerodynamic balance and controllability of the airplane
What force makes a airplane turn
horizontal component of lift
To correct for adverse yaw
use rudder
What force makes an airplane turn
the horizontal component of lift
An increase in load factor will cause the airplane to stall at
higher airspeeds
The amount of excess load put on a wing of an airplane depends on the
speed of the airplane
At high angles of attack P-factor causes
left yaw
When is torque effect the greatest
High power, low airspeeds and high angles of attack
In severe turbulence you want to _____ your speed to ______ or slightly below
Reduce / Maneuvering (Va)
In severe turbulence, maintain _____ _____ _____ and allow _______________
level flight attitude and allow minor variations in airspeed and altitude
White ARC on airspeed indicator represents
flap operating range
Lower limit of White ARC represents
power-off stalling speed with flaps and landing gear in the landing position
Lower limit of Green ARC represents
Power-off stalling speed with flaps/landing gear retracted or in a specified configuration
Upper limit of green arc represents
Maximum Structural Cruising Speed (Vno)
Vne
Never Exceed Speed - Maximum speed flown in calm air
Red line of airspeed indicator represents
Never Exceed Speed (Vne)
Wingtip Vortices are at greatest strength when the aircraft is
Heavy / Clean (flaps up) / Slow
Wingtip Vortices _____ behind an airplane
Sink
The condition that requires maximum caution when avoiding wake turbulence on landing is a
light quartering tailwind
When landing behind a large aircraft, the pilot should avoid wake turbulence by
fly above landing aircraft flightpath and land beyond where the larger aircraft’s nose wheel touched the ground
When departing behind a large aircraft, the pilot should avoid wake turbulence by maneuvering the aircraft
above and upwind from the heavy aircraft
How does the wake turbulence vortex circulate around each wingtip
outward, upward, and around each tip
________ caused by interference of Earth’s surface with airplane airflow patterns
Ground Effect
Ground effect ______ lift and _____ drag
increased / decreases
One problem of ground effect
in takeoff airplane may become airborne before reaching takeoff speed
What is ground effect
The result of the interference of the surface of the earth with the airflow patterns about an airplane
What does Vr mean?
Rotation speed. Recommended speed to start applying back pressure on the yoke, rotating the nose so, ideally, the aircraft lifts off the ground at VLOF.
What does Vne mean?
Never-exceed speed — “red line.” Applies only to piston-powered airplanes. This speed is never more than 90 percent of VDF. G loads imposed by any turbulence can easily overstress an aircraft at this speed.
What does Vg mean?
Best glide speed. This speed decreases as weight decreases.
What does Vc mean?
Design cruising speed. Speed at which the aircraft was designed to cruise. The completed aircraft may actually cruise slower or faster than VC. It is the highest speed at which the structure must withstand the FAA’s hypothetical “standard 50 fps gust.”
The amount of excess load that can be imposed on the wing of an airplane depends upon the….
Speed of the airplane
What determines the longitudinal stability of an airplane
The location of the CG with respect to the center of lift
Which color on the airspeed indicator identifies the power off stalling speed in a specified configuration?
the lower limit of the green arc
During an approach to a stall, an increased load factor will cause the airplane to
Stall at a higher airspeed
