Vortices - Wake Turbulance - Beechcraft Musketeer Sport III A23-19 Pilot Operating Handbook

~ft
Single Englne {Piston)
Sectlon X
Safety lnformatlon
raspond to the throttle when it is desired to discontinua the
descent 8oth problems are amenable to one solution: main-
tein adequate power to keep cylinder head temperatura in
the "'green"' range during descent, and lean to best power
mfxture (that is, progressively enrich the mixture from cruise
only slightly as altitude decreases). This procedura will
lengthen the descent, of course, and requires some
advance planning. lf it is necessary to make a prolongad
descent at or near idle, as in practicing forced landings, at
least avoid the problem of fouled spark plugs by frequently
advancing the throttle until the engine runs smoothly, and
maintain an appropriate mixture setting with altitude.
(Refer
to pre-landing check list.)
VORTICES • WAKE TURBULENCE
Every airplane generates wakes of
turbułance
while in flight.
Part of this is from the propeller or jet engine, and part from
the wing tip vortices. The larger and heavier the airplane,
the more pronounced and turbulant the wakes will be. Wing
tip vortices from large, heavy airplanes are very severe at
close range, degenerating with time, wind and distance.
These are rolling in nature, from each wing tip. In tests, vor-
tex velocities of 133 knots have been recorded. Encounter-
ing the rolling effect of wing tip vortices within two minutes
after passage of large airpfanes is most hazardous to light
airplanes. This roll effect can exceed the maximum counter-
roll obtainable in a light airplane. The turbulant areas may
remain for as long as three minutes or more, depending on
wind conditions, and may extend several miles behind the
airplane. Plan to fly slightly above and to the windward side
of other airplanes. Because of the wide variety of conditions
that can be encountered, there is no set rule to follow to
avoid wake turbulence in all situations. However, the Air-
man's lnformation Manual, and to a greater extent Advisory
Circular 90-23, Aircraft Wake Turbulence, provide a thor-
ough discussion of the tactors you should be aware of when
wake turbulence may be encountered.
May, 1994
10-39