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AIM

4/20/23

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Wake Turbulence

1.

From an intersection on the same runway (same or opposite direction) behind a departing 

 large

 aircraft

(except B757), or

2.

In the opposite direction on the same runway behind a large aircraft (except B757) takeoff or low/missed

approach.

NOTE

This 3

minute interval may be waived upon specific pilot request.

d.

A 3

minute interval will be provided when a small aircraft will takeoff:

1.

From an intersection on the same runway (same or opposite direction) behind a departing B757, or

2.

In the opposite direction on the same runway behind a B757 takeoff or low/missed approach.

NOTE

This 3

minute interval may not be waived.

e.

A 4

minute interval will be provided for all aircraft taking off behind a super aircraft, and a 3

minute

interval will be provided for all aircraft taking off behind a heavy aircraft when the operations are as described
in subparagraphs c1 and c2 above, and are conducted on either the same runway or parallel runways separated
by less than 2,500 feet. Controllers may not reduce or waive this interval.

f.

Pilots may request additional separation (i.e., 2 minutes instead of 4 or 5 miles) for wake turbulence

avoidance. This request should be made as soon as practical on ground control and at least before taxiing onto
the runway.

NOTE

14 CFR Section 91.3(a) states: “The pilot

in

command of an aircraft is directly responsible for and is the final authority

as to the operation of that aircraft.”

g.

Controllers may anticipate separation and need not withhold a takeoff clearance for an aircraft departing

behind a 

large, heavy, 

or

 super

 aircraft if there is reasonable assurance the required separation will exist when

the departing aircraft starts takeoff roll.

NOTE

With the advent of new wake turbulence separation methodologies known as Wake Turbulence Recategorization, some of
the requirements listed above may vary at facilities authorized to operate in accordance with Wake Turbulence
Recategorization directives.

REFERENCE

FAA Order JO 7110.659 Wake Turbulence Recategorization.
FAA Order JO 7110.123 Wake Turbulence Recategorization 

  Phase II.

FAA Order JO 7110.126, Consolidated Wake Turbulence.

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10. Development and New Capabilities

a.

The suite of available wake turbulence tools, rules, and procedures is expanding, with the development of

new methodologies. Based on extensive analysis of wake vortex behavior, new procedures and separation
standards are being developed and implemented in the US and throughout the world.  Wake research involves
the wake generating aircraft as well as the wake toleration of the trailing aircraft.

b.

The FAA and ICAO are leading initiatives, in terminal environments, to implement next

generation wake

turbulence procedures and separation standards. The FAA has undertaken an effort to recategorize the existing
fleet of aircraft and modify associated wake turbulence separation minima. This initiative is termed Wake
Turbulence Recategorization (RECAT), and changes the current weight

based classes (Super, Heavy, B757,

Large, Small+, and Small) to a wake

based categorical system that utilizes the aircraft matrices of weight,

wingspan, and approach speed. RECAT is currently in use at a limited number of airports in the National Airspace
System.