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of the small scope for energy
conversion, less amounts of excess
engine power and the amount of
drag from the gear and flaps, which
is not to say that landing is that
much better.
In extremely simple terms, where
windshear is expected, you should
have a little extra airspeed in hand;
you can help with the following:
Operational Procedures 111
· On take-off, use the longest
runway, less flap and more
airspeed up to about 1000 feet
agl, but watch your gradient and
use about 10 kts more than
usual. If shear is indicated by
rapidly fluctuating airspeed
and/or rate of climb or descent,
apply full power and aim to
achieve maximum lift and
distance from the ground. Be
prepared to make relatively
harsh control movements and
power changes, using full
throttle if you have to—new
engines are cheaper than new
aircraft.
· In a jet, you can use higher
angles of attack and still get a
sizeable amount of lift for a
moderate increase in drag,
because the wings are designed
that way. Various methods are
used to inform you of the stall,
and you want to keep the thing
flying just above that point—
something that may require
some practice in a simulator.
Similarly, if the shear is
encountered during the
approach, positive application
of power and flying controls
should keep the speed and rate
of descent within normal limits;
if there is any doubt, abandon
the approach and take action as
above.
· Set the prop RPM to maximum
(for flat pitch).
Windshear should be reported to
ATC as soon as possible, for the
benefit of others. It can be detected
by radar, using Doppler Shift to
calculate how fast raindrops are
moving and subsequently the pattern
of air movement, specifically looking
for headwind/tailwind
combinations. In theory, this
technology could also be used to
detect turbulence at higher levels,
assuming raindrops are present.
Your Company has to provide a
formal windshear training program.
If they don’t, there is an FAA video
available from the CAA to AOC
holders only.
Jetstreams
These occur at the tropopause, or
the boundary between lower air
(troposphere) and the stratosophere,
where it collects and channels air
into a high-speed stream due to a
strong horizontal temperature
gradient. They lie to the North of
frontal systems where the
temperature gradient is greatest, and
are stronger in Winter. To qualify for
the name, the windspeed must be at
least 60 kts. A jetstream may only be
a few hundred miles wide, but be
thousands of miles long. They have
extreme turbulence associated with
them, which can extend as much as
15000 feet below the tropopause,
usually on the polar side—also, head
wind components will naturally
increase your fuel consumption for
the trip. Bear in mind that the
tropopause lowers in Winter, which
will move the unstable air beneath
the jetstream further downwards as
well (it’s unstable because the
jetstream is sucking it up like a
vacuum).
Shallow fog
In shallow fog, you may be able to
see the whole of the approach
and/or runway lights from a
considerable distance, even though
112 Operational Flying
reports from the aerodrome indicate
fog. On descending into the fog
layer, your visual reference is likely
to drop rapidly, in extreme cases
from the full length of the runway
and approach lights to a very small
segment. This may give the
impression that you're pitching nose
up, making you more likely to hit the
ground after corrective movements.
You should be prepared for a missed
approach whenever you have the
slightest doubt about forward
visibility. The minimum RVR for
landing from a visual circuit is 800m.
Whiteout
Defined by the American
Meteorological Society as “An
atmospheric optical phenomenon of
the polar regions in which the
observer appears to be engulfed in a
uniformly white glow”. That is, you
can only see dark nearby objects –
no shadows, horizon or clouds, and
you lose your depth perception. It
occurs over unbroken snow cover
beneath a uniformly overcast sky,
when the light from both is about
the same. Blowing snow doesn’t
help. It’s particularly a problem if the
ground is rising. Once you suspect
whiteout, you should immediately
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