Loading & Performance

When you fly faster and lower the angle of attack, the center of pressure moves ___

aft

When you change the ____, you change the center of pressure, affecting the aerodynamic balance and controllability of the aircraft

angle of attack

Under which condition is pressure altitude and density altitude the same value?

at standard temp

The acute angle A (between chord line and relative wind) is the angle of

attack

The angle between the chord line of an airfoil and the relative wind is known as the angle of

attack

If an unmanned airplane weighs 33 pounds, what approximate weight would the airplane structure be required to support during a 30° banked turn while maintaining altitude?

38 pounds

If an unmanned aircraft weighs 20 pounds, what approximate weight would the aircraft structure be required to support during a 60° banked turn while maintaining altitude?

40 lbs Total Load = Weight x Load Factor TL = 20 x 2 T = 40

What is the relationship of lift, drag, thrust, and weight when the airplane is in straight-and-level flight? A. Lift equals weight and thrust equals drag B. Lift, drag, and weight equal thrust C. Lift and weight equal thrust and drag

A. Lift equals weight and thrust equals drag

To ensure the unmanned aircraft center of gravity (CG) limits are not exceeded, follow the aircraft loading instructions specified in the A. Pilot's Operating Handbook or UAS Flight Manual B. Aeronautical Information Manual (AIM) C. Aircraft Weight and Balance Handbook

A. Pilot's Operating Handbook or UAS Flight Manual

Hot weather, High altitude, Humid air ______ aircraft performance

decrease

What effect, if any, does high humidity have on aircraft performance?

decreases performance presence of water vapor displaces some of the air molecules in the atmos. causing the air to be less dense. decreased density causes decreased performance.

Moment is the

force applied by weight

The longitudinal axis runs

fore and aft from the nose to tail

When you fly slower, the center of pressure moves ____ (forward/backward)

forward

When molecules are far apart, you're said to have a ____ density altitude

high density altitude

An increase in load factor will cause the aircraft to stall at a ____(higher/lower) airspeed

higher

If the outside air temperature (OAT) at a given altitude is warmer than standard, is the density altitude higher or lower than pressure altitude?

higher

The lateral axis runs

horizontally parallel to the wings

In unaccelerated flight, the four forces are:

in equilibrium. Also known as straight and level flight. Lift=weight and thrust=drag.

G's ______ (increase/decrease) with maneuvers such as steeper bank angles or pulling up from a dive

increase

Load factor and stall speed increase exponentially as the bank angle _________

increases

At lower speed the aircraft becomes ____ (more/less) stable

less

As you increase the angle of attack, ___ gets greater

lift

The angle of attack determines how much ___ there will be on the wing

lift

The four forces acting on an airplane in flight are

lift, weight, thrust, drag

When the nose of an aircraft pitches up or down it is pitching about the lateral axis, but is said to be moving _____

longitudinally

At higher speed the aircraft becomes ____ (more/less) stable

more

arms

numbers that indicate how far you are from the datum line / zero point

Movement about the lateral axis is called

pitch

When you reduce power the nose of the aircraft can have a tendency to ____ ____ as the down force on the tail is reduced

pitch down

According to 14 CFR part 107, who is responsible for determining the performance of a small unmanned aircraft?

remote PIC

Movement about the longitudinal axis is called

roll

If you load the aircraft aft of the allowable rear CG limit, you may have difficulty recovering from a ____ condition

stalled

datum line

the zero point; the point you are measuring from

The forces acting on an aircraft in flight are in equilibrium when thrust is equal to ____ and lift is equal to ____

thrust = drag, lift = weight

Low pressure will occur on ___ (top/bottom) of the airfoil

top

Operating outside of the weight and balance limits of an unmanned aircraft A. can result in loss of control of the aircraft B. increases performance C. is not possible per aircraft design

A. can result in loss of control of the aircraft

The term "angle of attack" is defined as the angle between the A. chord line of the wing and the relative wind B. airplanes longitudinal axis and that of the air striking the airfoil C. airplane's centerline and the relative wind

A. chord line of the wing and the relative wind

What could be a consequence of operating a small unmanned aircraft above its maximum allowable weight? A. shorter endurance B. faster speed C. increased maneuverability

A. shorter endurance

Angle of Attack

Acute angle between chord line and relative wind

At any pressure altitude, under standard conditions the molecules are _____ _____, air is ____ (cooler/warmer), airplane is at a ____ (little higher/little lower) density altitude than under warm conditions

under standard conditions the molecules are closer together, air is cooler, airplane is at a little lower density altitude

At any pressure altitude, under warm conditions the molecules are _____ _____, air is ____ (more/less) dense, airplane is at a ____ (higher/lower) density altitude

under warm conditions the molecules are further apart, air is less dense, airplane is at a higher density altitude

moment =

weight x arm (force x distance)

Total Load = ______ x ________

weight x load factor

Movement about the vertical axis is called

yaw

An unmanned aircraft has been loaded in such a manner that the CG is located aft of the aft CG limit. One undesirable flight characteristic a remote pilot might experience with this aircraft would be A. a longer takeoff run B. difficulty in recovering from a stalled condition C. stalling at higher-than-normal airspeed

B. difficulty in recovering from a stalled condition

What effect does high density altitude, as compared to low density altitude, have on propeller efficiency and why? A. efficiency is increased due to less friction on the propeller blades B. efficiency is reduced because the propeller exerts less force at high density altitudes C. efficiency is reduced due to the increased force of the propeller in the thinner air

B. efficiency is reduced because the propeller exerts less force at high density altitudes

Which factor would tend to increase the density altitude at a given airport? A. increase in barometric pressure B. increase in ambient temp C. decrease in relative humidity

B. increase in ambient temp

What effect does high density altitude have on efficiency of a UA propeller? A. propeller efficiency is increased B. propeller efficiency is decreased C. density altitude does not affect propeller efficiency

B. propeller efficiency is decreased As density altitude increases there are fewer molecules for the propeller to push against

What effect does high density altitude have on aircraft performance A. increases engine performance B. reduces climb performance C. increases takeoff performance

B. reduces climb performance engine performance is reduced; air is thinner and longer distance is needed to generate the lift required for takeoff

An airplane said to be inherently stable will A. be difficult to stall B. require less effort to control C. not spin

B. require less effort to control

The amount of excess load that can be imposed on the wing of an airplane depends upon the A. position of the CG B. speed of the airplane C. abruptness at which the load is applied

B. speed of the airplane

When operating an unmanned airplane, the remote pilot should consider that the load factor on the wings may be increased any time A. the CG is shifted rearward to the aft CG limit. B. the airplane is subjected to maneuvers other than straight-and-level flight. C. the gross weight is reduced.

B. the airplane is subjected to maneuvers other than straight-and-level flight.

In weight and balance calculations, arm is A. the distance between items B. the distance from the datum line to the item C. weight times moment

B. the distance from the datum line to the item

What is density altitude? A. the height above the standard datum plane B. the pressure altitude corrected for non-standard temp C. the altitude read directly from the altimeter

B. the pressure altitude corrected for non-standard temp *indicated altitude is the altitude read directly from the altimeter

Under which condition will pressure altitude be equal to true altitude? A. when the atmospheric pressure is 29.92 inHg B. when standard atmospheric conditions exist C. when indicated altitude is equal to the pressure altitude

B. when standard atmospheric conditions exist

T/F: The critical angle of attack remains the same regardless of a change in gross weight

True

T/F: There is only lift as long as air conforms to the surface of the wing

True

How would high density altitude affect the performance of a small unmanned aircraft? A. increased performance B. decreased performance C. no change in performance

B. decreased performance high density altitude reduces aircraft takeoff and climb performance due to reduced engine performance and less aerodynamic performance of propeller/rotor and wings due to less density of the air

Moment / Weight =

Arm

At any pressure altitude, under cold conditions the molecules are very _____ _____, air is ____ (more/less) dense than under standard conditions, airplane is at a ____ (higher/lower) density altitude than under standard conditions

At any pressure altitude, under cold conditions the molecules are very close together, air is more dense than under standard conditions, airplane is at a lower density altitude than under standard conditions

T/F: An aircraft that is inherently stable will require less effort to control

True

If an unmanned aircraft weighs 45 pounds, what approximate weight would the aircraft structure be required to support during a 45° banked turn while maintaining altitude? A. 45 pounds. B. 63 pounds. C. 72 pounds.

B. 63 pounds.

Which basic flight maneuver increases the load factor on an airplane as compared to straight-and-level flight? A. Climbs B. Turns C. Stalls

B. Turns

At what bank angle for a turn does the additional force on the wings become significant? A. 15 degrees B. 30 degrees C. 45 degrees

C. 45 degrees

Which statement relates to Bernoulli's principle? A. For every action there is an equal and opposite reaction B. An additional upward force is generated as the lower surface of the wing deflects air downward. C. Air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface

C. Air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface

Changes in the center of pressure of a wing affect the aircraft's A. lift/drag ratio. B. lifting capacity. C. aerodynamic balance and controllability.

C. aerodynamic balance and controllability.

Center of gravity can be found by A. multiplying weight times arm B. dividing total weight by total moment C. dividing total moment by total weight

C. dividing total moment by total weight

A stall occurs when the smooth airflow over the unmanned airplane`s wing is disrupted, and the lift degenerates rapidly. This is caused when the wing: A. exceeds the maximum speed. B. exceeds maximum allowable operating weight C. exceeds its critical angle of attack

C. exceeds its critical angle of attack

T/F: The aircraft will stall at the same indicated airspeed at high altitude as at low altitude

True

If the outside air temperature (OAT) at a given altitude is warmer than standard, the density altitude is A. equal to pressure altitude B. lower than pressure altitude C. higher than pressure altitude

C. higher than pressure altitude As the OAT increases the air becomes less dense and results in higher density altitude (The temp must be standard for the pressure and density alt. to be equal. The temp would have to be below standard for the density alt. to be lower than the pressure alt.)

The angle of attack at which an airplane wing stalls will A. increase if the CG is moved forward B. change with an increase in gross weight C. remain the same regardless of gross weight

C. remain the same regardless of gross weight

Total moment / Total weight =

Center of gravity

When are the four forces that act on an airplane in equilibrium?

During unaccelerated flight

Any load on the wings of the aircraft is measured in

G's

____ are a measure of load factor on the aircraft

G's

Which combination of atmospheric conditions will reduce aircraft takeoff and climb performance? (Triple H's)

High temp, high relative humidity, high density altitude

Over the wing of an airplane you have a ___ pressure area over the top of the wing, and relative ___ pressure area underneath the wing, creating lift.

LOW pressure area over the top of the wing, HIGH pressure area underneath the wing

According to Bernoulli's law, where air is going the fastest, such as over the curved top of a wing, the air pressure is ____ (less/higher)

Less

Weight x Arm =

Moment

Unaccelerated flight

Not changing speed or direction

Density Altitude

Pressure altitude corrected for non-standard temperature Tells you how far apart the molecules are compared to the standard atmosphere, and how well the aircraft will perform

Pressure Altitude

Tells you how much air pressure there is on an aircraft (Height above the standard datum plane when 29.92 is set in the altimeter.)

Critical Angle of Attack

The angle of attack at which an aircraft stalls (loses lift) regardless of the aircraft's airspeed, altitude, or weight.

What determines the longitudinal stability (pitch stability) of an aircraft?

The location of the center of gravity in relation to the center of lift

What four forces act on an aircraft as it flies?

Thrust, Drag, Weight, Lift

center of gravity = (formula)

Total moment / Total weight

Moment / Arm =

Weight

Moving the center of gravity (CG) around, power changes, changing the angle of attack all affect the ____ of an aircraft

controllability