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AIM 

6/17/21 

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 Recategoriza-

tion, 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

genera-

tion 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 Recategoriza-
tion (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. 

Wake Turbulence 

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