AIM
4/20/23
7
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4
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8
Wake Turbulence
EXAMPLE
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A puff of smoke may appear at the 1,000
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foot markings of the runway, showing that touchdown was that point; therefore,
adjust point of intended landing to the 1,500
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foot markings.
(d)
Maintain the line
−
of
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sight to the point of intended landing above and ahead of the heavier preceding
aircraft; maintain it to touchdown.
(e)
Land beyond the point of landing of the preceding heavier aircraft. Ensure you have adequate runway
remaining, if conducting a touch
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and
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go landing, or adequate stopping distance available for a full stop landing.
f.
During visual approaches pilots may ask ATC for updates on separation and groundspeed with respect to
heavier preceding aircraft, especially when there is any question of safe separation from wake turbulence.
g.
Pilots should notify ATC when a wake event is encountered. Be as descriptive as possible (i.e., bank angle,
altitude deviations, intensity and duration of event, etc.) when reporting the event. ATC will record the event
through their reporting system. You are also encouraged to use the Aviation Safety Reporting System (ASRS)
to report wake events.
7
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4
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9. Air Traffic Wake Turbulence Separations
a.
Because of the possible effects of wake turbulence, controllers are required to apply no less than minimum
required separation to all aircraft operating behind a Super or Heavy, and to Small aircraft operating behind a
B757, when aircraft are IFR; VFR and receiving Class B, Class C, or TRSA airspace services; or VFR and being
radar sequenced.
1.
Separation is applied to aircraft operating directly behind a super or heavy at the same altitude or less
than 1,000 feet below, and to small aircraft operating directly behind a B757 at the same altitude or less than 500
feet below:
(a) Heavy
behind
super
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6 miles.
(b) Large
behind
super
−
7 miles.
(c) Small
behind
super
−
8 miles.
(d) Heavy
behind
heavy
−
4 miles.
(e) Small/large
behind
heavy
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5 miles.
(f) Small
behind
B757
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4 miles.
2.
Also, separation, measured at the time the preceding aircraft is over the landing threshold, is provided
to small aircraft:
(a) Small
landing behind
heavy
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6 miles.
(b) Small
landing behind
large, non
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B757
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4 miles.
REFERENCE
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Pilot/Controller Glossary Term
−
Aircraft Classes.
b.
Additionally, appropriate time or distance intervals are provided to departing aircraft when the departure
will be from the same threshold, a parallel runway separated by less than 2,500 feet with less than 500 feet
threshold stagger, or on a crossing runway and projected flight paths will cross:
1.
Three minutes or the appropriate radar separation when takeoff will be behind a super aircraft;
2.
Two minutes or the appropriate radar separation when takeoff will be behind a heavy aircraft.
3.
Two minutes or the appropriate radar separation when a small aircraft will takeoff behind a B757.
NOTE
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Controllers may not reduce or waive these intervals.
c.
A 3
−
minute interval will be provided when a
small
aircraft will takeoff: