Lesson 10/11 Wake Turbulence & AC Characteristics Flashcards
Vortices
circular patterns of air created by the movement of an airfoil through the air when generating lift
Wake Turbulence
a phenomenon resulting from the passage of an aircraft through the atmosphere. The term includes vortices, thrust stream turbulence, jet blast, jet wash, propeller wash, and rotor wash both on the ground and in the air.
______ are a by product of wing lift, and are the most predominant parts of aircraft wake turbulence.
Vortices
What is the strength of a vortex governed by? (3)
- weight
- shape of the wing (wing configuration) (determines wing loading)
- speed of the generating aircraft
The greatest vortex strength is generated when the aircraft is _________.
heavy, clean, and slow
What is the greatest factor that affects the intensity of wake turbulence?
WEIGHT of the aircraft
Clean Configuration
allows for a stronger vortex to be generated because without flaps the wing has a smaller area and wing loading is therefore greater per square foot
Dirty Configuration
increases the total wing area and decreases the wing loading. The flaps also disrupt the airflow over the wing and break down the formation of the vortex.
The strength of these vortices will diminish with _____ and _____.
time; distance
If you have an aircraft on approach to an airport and a similar aircraft cruising during en route flight, which would create a greater wake turbulence effect?
approach
____ is generated by the creation of pressure differential over the wing surface.
Lift
____ pressure above the wing.
____ pressure below the wing.
Lowest; Highest
______ is a swirling air mass off of the wing tips trailing behind the aircraft.
‘Wake Vortex’ or ‘Wing Tip Vortices’
When viewing aircraft from behind, vortex circulation off the wingtip is ______ off the right wing; _____ off the left wing.
counterclockwise; clockwise
What is the name for the turbulent phenomenon created by aircraft passing through the atmosphere?
wake turbulence
Vortices are generated at the moment the aircraft _______.
generates lift (nose wheel leaves the ground)
Vortices ______ at the moment the aircraft stops generating lift.
discontinue (all landing gear has touched down)
What is the vortex sink rate?
approx 300 to 500 feet per minute
When does the vortex sink rate normally level off?
500 to 1,000 feet below the flight path
When close to the ground and there is zero wind, vortices from large aircraft will move laterally within in ____ to ____ of the ground and _ to __ laterally.
100 feet; 200 feet
2 knots; 3 knots
Crosswinds of 1 to 5 knots will _____________ the movement of one vortex while increasing the movement of another vortex.
decrease or stall
________ can move vortices into the landing zones of aircraft that were originally trying to avoid the wake.
Tailwinds
Induced roll
the mechanical force a wake vortex has on an aircraft. With no counter control (roll control) the aircraft would roll completely, spinning on its longitudinal axis until the vortex sufficiently weakened.
Roll Control
the ability of an aircraft to move around the longitudinal axis
The ability of an aircraft to counteract the effects of the roll (counter control) is based on two things:
- wingspan of the aircraft
- counter control capability of the aircraft
Counter control is most effective and roll is minimal when the wingspan and the ailerons extend beyond the ________ of the vortex.
outer edges
In a slow hover taxi or a stationary hover, a helicopter will generate a _________ from its main rotors. These outward vortices will spread out to a distance of approximately _______ the diameter of the rotor in _____ directions.
downwash; three times; all
Helicopters will generate a pair of wingtip vortices when in __________.
forward flight
Jet Blast
jet engine exhaust (thrust stream turbulence); normally experienced during ground operations and during initial takeoff roll prior to lift
Is the controller responsible for anticipating wake turbulence’s existence or effects?
no
When issuing a cautionary advisory during ground operations controllers may use the following terms in lieu of the term wake turbulence:
- jet blast
- prop wash
- rotor wash
Wake turbulence has the greatest impact on ATC in the areas of ____________.
increased separation and traffic management delays
Aircraft are divided into ____ categories, name them.
3; Cat I, Cat II, Cat III
Category I Aircraft
- weight: 12,500 lbs or less
- Single Engine
- Propeller Driven
- All Helicopters
Category II Aircraft
- Weight: 12,500 lbs or less
- Twin Engine
- Propeller Driven
Category III Aircraft
Any other aircraft not described in either CAT I or CAT II
Cat I General Performance Characteristics
- Speed: 100-160 knots
- Altitude: 10,000 feet and below
- Climb Rate: 1,000 feet per minute or less
- Weight Class: Small (S)
Cat II General Performance Characteristics
- Speed: 160-250 knots
- Altitude: FL240 and below
- Climb Rate: 1,000-2,000 feet per minute
- Weight Class: Small (S)
Cat III General Performance Characteristics
- Speed: 300-550 knots
- Altitude: FL450 and below
- Climb Rate: 2,000 - 4,000 feet per minute
- Weight Class: Specified for each aircraft
Helicopter’s General Performance Characteristics
- Speed: 90-160 knots
- Altitude: FL200 and below
- Climb Rate: 500-2,150 feet per minute
- Weight Class: Small (S) - Large (L)
Aircraft of 41,000 pounds or less maximum certified takeoff weight are in what weight class?
Small
Large Aircraft are aircraft of more than __________ , maximum certified takeoff weight, up to but not including __________.
41,000 lbs; 300,000 lbs
______ are aircraft capable of takeoff weights of 300,000 or more pounds whether or not they are operating at this weight during a particular phase of flight.
Heavy
An aircraft designator may contain as many as __________, but no less than _______.
four characters; two characters
The First character of an aircraft designator must be a _____.
letter
Military Designators: A, B, C, E, F, H, P, T, K
A- Attack B- Bomber C- Cargo Transport E- Electronic (ECM) F- Fighter H- Helicopter P- Patrol T- Trainer K- Tanker/Refueling
List the 9 different Aircraft Identification Features:
- size
- engine location and number
- engine type
- wing placement
- wing configuration
- tail configuration
- windows
- fuselage shape
- landing gear
Name the 3 Aircraft Engine Types:
- reciprocating
- turboprop
- turbojet
Name the 3 types of Wing Placement:
- High Wing
- Mid Wing
- Low Wing
Name the 3 basic wing configurations:
- straight wing
- swept wing
- delta wing
Name the 5 basic tail configurations:
- Conventional tail
- Forward slant vertical stabilizer
- Horizontal stabilizer about fuselage (mid tail)
- “T” Tail (swept or straight)
- “V” Tail
Name the 5 types of windows:
- oval
- round
- teardrop
- square
- bubble canopy
Name the 2 types of landing gear:
- tricycle
- conventional (taildraggers)
Name the two types of landing gear configurations:
- fixed gear
- retractable gear
