Home > Preview
The flashcards below were created by user
Anonymous
on FreezingBlue Flashcards.

Minimum takeoff speed is ___ above the poweroff stall speed
20%

Minimum takeoff speed can be reduced by:
 Decreasing weight
 Increasing wing surface area
 Increasing C_{LMAX}

Weight is the greatest factor in ___ ____
takeoff distance

Increasing density altitude does what to aircraft performance?
 higher takeoff velocity
 reduces thrust available
 decreases acceleration
 increases takeoff distance

What causes a high density altitude?
 high airport elevation; hight temperature; increased humidity
 High, hot and humid are bad for takeoff performance

Max rate of climb:
 gaining the most altitude in a given amount of time
 Relies on excess power
 140 KIAS

Max angle of climb:
 Most altitude for distance traveled
 Relies on excess thrust
 Slower than max rate of climb
 Not flown in the T6

T or F: Max rate of climb is not changed by wind.
True

What does max endurance rely on?
 Power required curve  lowest amount of powered required
 At a speed that is less than L/D_{MAX}
 AOA that is higher than L/D_{MAX}

What does max range rely on?
 Minimum amount of fuel per unit of velocity
 At L/D_{MAX} velocity and AOA

How do weight, altitude and configuration affect cruise performance?
 Weight  more lift needed, more power to generate lift, higher fuel flow, max range/endurance decrease
 Altitude  higher altitude=lower temp more efficient, increase max range/endurance
 Configuration  Dirty airplane decreases max range/endurance

T or F: Winds have no effect on maximum endurance since maximum endurance is only concerned with time airborne
True

What is critical mach number?
 The Mach number that first produces evidence of local supersonic flow
 Mach number is the ratio of TAS to local speed of sound

Define best glide speed.
 The airspeed flown power off which provided max range
 Occurs at L/D_{MAX} but changes with wieght
 125 KIAS

What is glide range?
Glide ratio  11:1; 11,000' horizontally for every 1,000' of altitude loss

How does weight impact max glide range?
has no impact

What is the greatest factor that affects landing distance?
Weight

Torque
 Occurs due to Newton's third law; a force of equal magnitude, but opposite direction
 Rolls the plane in the opposite direction; counterclockwise

PFactor
 The yawing moment caused by one blade producing more thrust than the opposing blade
 Poweron descent higher AOA on ascending blade; nose yaws right
 Poweron climb Higher AOA on descending blade; nose yaws left

Slipstream swirl
 corkscrewing airflow that travels around the fuselage and strikes the vertical stabilizer on the left, pushing tail right, nose left.
 High airspeed, power settings

Gyroscopic precession
 Applied force to the edge of a spinning object parallel to the rotational axis, will result in a force that is created 90° ahead in the direction of rotation

Adverse yaw is created by what?
More drag being created on the down aileron than the up aileron, pulling the nose in the direction of the down aileron

Aircrafts turn performance is based on what?
Velocity and bank angle

Max turn rate and minimum turn radius are achieved by?
90° of bank and minimum velocity

In a level turn, as bank angle increases, G loading ____.
increases

Define limit load factor.
The greatest load factor and airplane can sustain without risk of permanent deformation or damage

What is ultimate load factor?
 The maximum load factor that an aircraft can withstand without structural failure
 150% of limit load factor

Symmetric G's are encountered only when
the elevator is deflected

Asymmetric loads are encountered only when ___
Ailerons or rudder are deflected in flight

Maneuvering speed
 the speed above which full or abrupt control movements in one axis can result in structural damage to the aircraft
 AKA: cornering velocity
 safely make the smallest radius turn
 227 KIAS

At 30° of bank, how many G's are required to maintain level flight?
1.15

At 45° of bank, how many G's are required to maintain level flight?
1.4

At 60° of bank, how many G's are required to maintain level flight?
2.0

At 80° of bank, how many G's are required to maintain level flight?
5.72

Static stability
The initial tendency of an object to move toward or away from its original equilibrium position

Dynamit stability
is the position and measure of displacement of an object after it has been disturbed with respect to time

Positive static stability
 The initial tendency of an object to return to its original equilibrium
 A ball, when displaced in the bottom of a bowl, will want to roll back to the bottom where it started

Negative static stability
 initial tendency of an object to move away from its original equilibrium.
 upside down bowl, ball will roll away from its original center point

Neutral static stability
 initial tendency of an object to accept the new position as a new equilibrium.
 A ball on a flat surface, when moved, does not move toward or away from its original position

Positive dynamic stability
damped oscillations eventually returning to equilibrium point

Negative dynamic stability
Undamped oscillations, object gets further from equilibrium with each oscillation

Neutral dynamic stability
oscillations never dampened, and remain constant in amplitude

Stability and maneuverability are ____ ____.
Inversely related

An airplane with the CG ahead of the AC will pitch ____ after the increase in AOA.
 down
 Positive contributor to longitudinal static stability

If the CG is aft of the AC, the airplane will tend to pitch ____ more away from equilibrium
 up
 Negative contributor to longitudinal static stability

Sideslip angle
Difference between the flight path and the longitudinal axis

Sideslip relative wind
Component of the relative wind that is parallel to the lateral axis

Are straight wings a positive or negative contributor to directional static stability?
Positive

What is the greatest positive contributor to directional static stability?
Vertical stabilizer

What is the greatest positive contributor to lateral static stability?
Wing dihedral

Wing sweep is a _____ contributor to lateral stability
positive

Vertical stabilizer is a _____ contributor to the lateral stability of an aircraft
positive

Crosscoupling
yaw will cause a roll and roll will cause a yaw

Directional divergence
 Crosscoupling
 An aircraft will continue to yaw and increase its sideslip angle in response to a small initial sideslip
 Negative directional static stability

Spiral divergence
 Crosscoupling
 Continue to yaw and roll in reaction to an initial sideslip, resulting in a tight descending spiral.
 Weak lateral stability (unable to correct back to wings level)

Dutch roll
 Crosscoupling
 Caused by a combination of strong lateral and weak directional stability
 The nose of an airplane experiencing a dutch roll scribes a figure eight in the air

Proverse roll
 Crosscoupling
 Tendency for an airplane to roll in the same direction as it is yawing

Adverse yaw
 Crosscoupling
 Tendency of the airplane to yaw away from the direction of aileron input

Phugoid oscillations
Long period oscillations of altitude and airspeed while maintaining a constant AOA

Pilot induced oscillations
 Short period oscillations in any three aircraft axes
 greatest hazard is pitch axes

Longitudinal static stability characteristics include:
 CG ahead of AC (aerodynamic center), airplane will pitch down after an increase in AOA  POSITIVE
 CG aft of AC, airplane will pitch up away from equilibrium  NEGATIVE

Directional static stability characteristics include:
 Vertical stabilizer  greatest POSITIVE
 Straight wings  small POSITIVE
 Swept wings  POSITIVE
 Fuselage  NEGATIVE

Lateral static stability characteristics include:
 Wing dihedral  greatest POSITIVE
 High wing placement  POSITIVE
 Low wing placement  NEGATIVE
 Wing sweep  POSITIVE
 Vertical stabilizer  POSITIVE

