24. Wake Turbulence Flashcards
Define Wake Turbulence
Wake Vortex Turbulence is defined as turbulence which is generated by the passage of an aircraft in flight.
It will be generated from the point when the nose landing gear of an aircraft leaves the ground on take offand will cease to be generated when the nose landing gear touches the ground during landing.
When another aircraft encounters such turbulence a Wake Vortex Encounter (WVE) is said to have occurred.
Wake turbulence categories
Super (J) -
Heavy (H) - All aircraft types of 136,000 kg or more
Medium (M) - Aircraft types less than 136,000 kg but more than 7,000 kg
Light (L) - Aircraft types of 7,000 kg or less
What are the basic effects of wake turbulence on AC? (4)
- Induced roll (Greatest Danger)
- Loss of height or rate of climb
- Possible structural stress
- Adverse effect on engine inc. flameout.
Where is a wake turbulence encounter cause greater effect on AC?
The approach area (or climb out)
because the following aircraft is in a critical state with regard to speed, thrust, altitude and reaction time.
When will an ATCU not apply Wake turbulence? (ICAO)
- For arriving VFR flights landing on the same runway as a preceding HEAVY or MEDIUM aircraft.
- Between arriving IFR flights executing a visual approach when the aircraft has reported the preceding aircraft in sight and has been instructed to follow and maintain own separation from the aircraft.
The ATC unit shall in respect of these flights as well as when otherwise deemed necessary, issue a caution of possible wake turbulence.
Arriving AC
Non-radar separation
A MEDIUM landing behind a SUPER = 3 minutes
A MEDIUM landing behind a HEAVY = 2 minutes
A LIGHT landing behind a SUPER = 4 minutes
A LIGHT landing behind a HEAVY/MEDIUM = 3 minutes
These separations are for timed instrument approaches (ie, an APP Control function.)
Other than this there is only a need to ‘caution wake turbulence’
Departing AC
2 minutes shall be applied between
- A non-A380-800 HEAVY taking-off behind a SUPER
- A LIGHT/MEDIUM taking-off behind a HEAVY or …
- A LIGHT taking-off behind a MEDIUM
3 minutes shall be applied between
A LIGHT/MEDIUM taking-off behind a SUPER when …
… aircraft are using:
The same runway or Parallel runways separated by less than 760m
INTERMEDIATE DEPARTURES
3 minutes shall be applied between
A LIGHT/MEDIUM taking-off behind a HEAVY Or
A LIGHT taking-off behind a MEDIUM
4 minutes shall be applied between
A LIGHT/MEDIUM taking-off behind a SUPER When Intermediate …
DISPLACED LANDING THRESHOLD
2 minutes shall be applied between
An arriving LIGHT/MEDIUM following a HEAVY departure Or
An arriving LIGHT following a MEDIUM departure, if the projected flight paths are expected to cross when operating on a runway with a displaced landing threshold.
2 minutes shall be applied between
A LIGHT/MEDIUM taking-off behind a HEAVY arrival Or
A LIGHT taking-off behind a MEDIUM arrival, when operating on a runway with a displaced landing threshold.
3 minutes shall be applied between
A LIGHT/MEDIUM taking-off behind a SUPER arrival Or
An arriving LIGHT/MEDIUM following a SUPER departure, if projected flight paths are expected to cross when operating on a runway with a displaced landing threshold.
OPPOSITE DIRECTION
2 minutes shall be applied between. A LIGHT/MEDIUM and a HEAVY. Or
A LIGHT and a MEDIUM when the heavier aircraft is making a low or missed approach, and
3 minutes shall be applied between
A LIGHT/MEDIUM and a SUPER when the heavier aircraft is making a low or missed approach, and the
lighter aircraft is: using an opposite direction runway for take-off 3 / 2 minutes after the time the heavier
aircraft commences missed approach/low pass, the lighter aircraft can depart or the lighter aircraft is:
landing on the same runway in the opposite direction or the lighter aircraft is: landing on a parallel
opposite direction runway separated by less than 760m
What is the difference between Wake Vortex & Wake Turbulence?
Vortex describes the nature of the air masses.
Turbulence is the effect of the vortices on other aircraft
