4/20/23
AIM
from the main rotor(s) in all directions. Pilots of small aircraft should avoid operating within three rotor diameters
of any helicopter in a slow hover taxi or stationary hover. In forward flight, departing or landing helicopters
produce a pair of strong, high
−
speed trailing vortices similar to wing tip vortices of larger fixed wing aircraft.
Pilots of small aircraft should use caution when operating behind or crossing behind landing and departing
helicopters.
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8. Pilot Responsibility
a.
Research and testing have been conducted, in addition to ongoing wake initiatives, in an attempt to mitigate
the effects of wake turbulence. Pilots must exercise vigilance in situations where they are responsible for
avoiding wake turbulence.
b.
Pilots are reminded that in operations conducted behind all aircraft, acceptance of instructions from ATC
in the following situations is an acknowledgment that the pilot will ensure safe takeoff and landing intervals and
accepts the responsibility for providing wake turbulence separation.
1.
Traffic information.
2.
Instructions to follow an aircraft; and
3.
The acceptance of a visual approach clearance.
c.
For operations conducted behind
super
or
heavy
aircraft, ATC will specify the word “
super
” or “
heavy
”
as appropriate, when this information is known. Pilots of
super
or
heavy
aircraft should always use the word
“
super
” or “
heavy
” in radio communications.
d.
Super, heavy, and large jet aircraft operators should use the following procedures during an approach to
landing. These procedures establish a dependable baseline from which pilots of in
−
trail, lighter aircraft may
reasonably expect to make effective flight path adjustments to avoid serious wake vortex turbulence.
1.
Pilots of aircraft that produce strong wake vortices should make every attempt to fly on the established
glidepath, not above it; or, if glidepath guidance is not available, to fly as closely as possible to a “3
−
1” glidepath,
not above it.
EXAMPLE
−
Fly 3,000 feet at 10 miles from touchdown, 1,500 feet at 5 miles, 1,200 feet at 4 miles, and so on to touchdown.
2.
Pilots of aircraft that produce strong wake vortices should fly as closely as possible to the approach course
centerline or to the extended centerline of the runway of intended landing as appropriate to conditions.
e.
Pilots operating lighter aircraft on visual approaches in
−
trail to aircraft producing strong wake vortices
should use the following procedures to assist in avoiding wake turbulence. These procedures apply only to those
aircraft that are on visual approaches.
1.
Pilots of lighter aircraft should fly on or above the glidepath. Glidepath reference may be furnished by
an ILS, by a visual approach slope system, by other ground
−
based approach slope guidance systems, or by other
means. In the absence of visible glidepath guidance, pilots may very nearly duplicate a 3
−
degree glideslope by
adhering to the “3 to 1” glidepath principle.
EXAMPLE
−
Fly 3,000 feet at 10 miles from touchdown, 1,500 feet at 5 miles, 1,200 feet at 4 miles, and so on to touchdown.
2.
If the pilot of the lighter following aircraft has visual contact with the preceding heavier aircraft and also
with the runway, the pilot may further adjust for possible wake vortex turbulence by the following practices:
(a)
Pick a point of landing no less than 1,000 feet from the arrival end of the runway.
(b)
Establish a line
−
of
−
sight to that landing point that is above and in front of the heavier preceding
aircraft.
(c)
When possible, note the point of landing of the heavier preceding aircraft and adjust point of intended
landing as necessary.
Wake Turbulence
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