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Minimum takeoff speed is ___ above the power-off stall speed
Minimum take-off speed can be reduced by:
- Decreasing weight
- Increasing wing surface area
- Increasing CLMAX
Weight is the greatest factor in ___ ____
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.
What does max endurance rely on?
- Power required curve - lowest amount of powered required
- At a speed that is less than L/DMAX
- AOA that is higher than L/DMAX
What does max range rely on?
- Minimum amount of fuel per unit of velocity
- At L/DMAX 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
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/DMAX 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?
- Occurs due to Newton's third law; a force of equal magnitude, but opposite direction
- Rolls the plane in the opposite direction; counterclockwise
- The yawing moment caused by one blade producing more thrust than the opposing blade
- Power-on descent- higher AOA on ascending blade; nose yaws right
- Power-on climb- Higher AOA on descending blade; nose yaws left
- corkscrewing airflow that travels around the fuselage and strikes the vertical stabilizer on the left, pushing tail right, nose left.
- High airspeed, power settings
- 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 ____.
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
- 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?
At 45° of bank, how many G's are required to maintain level flight?
At 60° of bank, how many G's are required to maintain level flight?
At 80° of bank, how many G's are required to maintain level flight?
The initial tendency of an object to move toward or away from its original equilibrium position
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 ____ ____.
An airplane with the CG ahead of the AC will pitch ____ after the increase in AOA.
- Positive contributor to longitudinal static stability
If the CG is aft of the AC, the airplane will tend to pitch ____ more away from equilibrium
- Negative contributor to longitudinal static stability
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?
What is the greatest positive contributor to directional static stability?
What is the greatest positive contributor to lateral static stability?
Wing sweep is a _____ contributor to lateral stability
Vertical stabilizer is a _____ contributor to the lateral stability of an aircraft
yaw will cause a roll and roll will cause a yaw
- An aircraft will continue to yaw and increase its sideslip angle in response to a small initial sideslip
- Negative directional static stability
- 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)
- 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
- Tendency for an airplane to roll in the same direction as it is yawing
- Tendency of the airplane to yaw away from the direction of aileron input
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
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