Wake Turbulence

Question 1

What is Wake Turbulence?

Answer 1

Rotating air masses generated behind the wing tips of aircraft, or behind rotor tips of helicopters in forward motion.

Question 2

What are rotating air masses generated behind the wing tips of aircraft, or behind rotor tips of helicopters in forward motion?

Answer 2

Wake Turbulence

Question 3

What are Vortices?

Answer 3

1. Circular patterns of air
2. created by the movement of an airfoil
3. through the air when generating lift.
4. Rotating column of air;
5. can be hazardous to aircraft.

Question 4

What are Circular patterns of air created by the movement of an airfoil through the air when generating lift. Rotating column of air; can be hazardous to aircraft?

Answer 4

Vortices

Question 5

What is Clean Configuration?

Answer 5

When an Aircraft is configured for flight with no flaps, gear retracted, and no other wing extensions, such as air brakes.

Question 6

What is the configuration when an Aircraft is configured for flight with no flaps, gear retracted, and no other wing extensions, such as air brakes.

Answer 6

Clean Configuration

Question 7

What is Dirty Configuration?

Answer 7

Aircraft is configured for flight with flaps, gear extended, and additional wing extensions, such as air brakes.

Question 8

What is the configuration when the Aircraft is configured for flight with flaps, gear extended, and additional wing extensions, such as air brakes?

Answer 8

Dirty Configuration

Question 9

What is Rollup Effect?

Answer 9

1. Difference in pressure above/below an airfoil
2. results in airflow twisting into
3. counter-rotating cylindrical vortices.

Question 10

What is the difference in pressure above or below an airfoil that results in airflow twisting into counter-rotating cylindrical vortices?

Answer 10

The Rollup Effect.

Question 11

What is an Induced Roll?

Answer 11

Mechanical force a wake vortex has on an aircraft. Without counter action, causes an aircraft to roll/spin on its longitudinal axis.

Question 12

What is the Mechanical force a wake vortex has on an aircraft called?

Answer 12

Induced Roll

Question 13

What is Downwash?

Answer 13

1. Wake turbulence generated from helicopters
2. in a slow or stationary hover,
3. pushing downwards and
4. outwards from the rotor.

Question 14

What is Wake turbulence generated from helicopters in a slow or stationary hover, pushing downwards and outwards from the rotor called?

Answer 14

Downwash

Question 15

What is Jet Blast?

Answer 15

Exhaust from a jet engine.

Question 16

What is Exhaust from a jet engine called?

Answer 16

Jet Blast

Question 17

What are the three factors that determine the intensity of wake turbulence?

Answer 17

Weight of the aircraft
Speed of the aircraft
Shape (configuration) of the airfoil

Question 18

Do all aircraft generate wake turbulence in flight?

Answer 18

Yes

Question 19

What effect does the weight of an aircraft have on wake turbulence?

Answer 19

More weight generates a higher force of turbulence.

Question 20

What is the most important factor for wake turbulence intensity?

Answer 20

Weight of the aircraft.

Question 21

What effect does the speed of the aircraft have on the wake turbulence?

Answer 21

Slower speed generates higher force.

Question 22

What effect does the speed of the aircraft have on the vortices it produces?

Answer 22

Vortices dissipate quicker at higher speeds.

Question 23

What effect does shape (configuration) of the airfoil have on wake turbulence?

Answer 23

Clean configuration generates higher force.

Question 24

How does wake turbulence diminish?

Answer 24

With time and distance from origination.

Question 25

When does a vortex begin?

Answer 25

Whenever an aircraft generates lift.

Question 26

When does a vortex end?

Answer 26

When lift is no longer produced.

Question 27

How do vortexes rotate?

Answer 27

Towards the aircraft.

Question 28

How do vortexes drift?

Answer 28

Away from the aircraft.

Question 29

At what rate do vortexes sink?

Answer 29

300’-500’ per minute

Question 30

How do vortexes move at or near ground level without wind?

Answer 30

Away from the aircraft at 2-3 knots.

Question 31

At what altitude will vortexes move away from the aircraft at 2-3 knots?

Answer 31

Ground Level

Question 32

How will small crosswinds affect the movement of vortexes?

Answer 32

Will stall movement of one vortex, and increase movement of the other.

Question 33

How do tail and headwinds affect the movement of vortexes?

Answer 33

Push the vortices in the direction they are blowing

Question 34

What are the 2 most common types of wake turbulence hazards?

Answer 34

1. Structural | 2. Induced Roll

Question 35

What hazard causes loss of aircraft control?

Answer 35

Induced Roll

Question 36

What two factors affect an aircraft's ability to recover from induced roll?

Answer 36

Wingspan | Counter control capability

Question 37

When is counter control most effective?

Answer 37

When wings extend past the edges of the vortex.

Question 38

When can Induced Roll be encountered?

Answer 38

Unpredictable and can be encountered in flight or on the ground.

Question 39

What are the 4 downwash characteristics of a helicopter?

Answer 39

High speed vortices. Pushes outward (away) from the rotor as it reaches the ground. Expands to approximately three times the rotor diameter. Expands in all directions.

Question 40

What are the 3 Vortex Characteristics of a Helicopter?

Answer 40

Wingtip vortices generated in forward flight. Similar to fixed wing. May be stronger than vortices from similar mass fixed wing aircraft.

Question 41

What is mandated to account for an mitigate the effects of Wake Turbulence?

Answer 41

Increased separation between aircraft.

Question 42

What can increased separation increase?

Answer 42

Delays

Question 43

Are controllers responsible for anticipating the existence or effects of wake turbulence?

Answer 43

No

Question 44

What do controllers need to issue in response to wake turbulence?

Answer 44

Cautionary advisories

Question 45

What is the cautionary advisory phraseology to issue in response to wake turbulence when the aircraft is on the ground?

Answer 45

CAUTION JET BLAST /PROPWASH | /ROTORWASH

Question 46

What is the cautionary advisory phraseology to issue in response to wake turbulence when the aircraft is in the air?

Answer 46

CAUTION WAKE TURBULENCE