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the climb (TOC) to the top of the
descent (TOD.
For most trips, fuel management
revolves around getting the
maximum range for a given amount
of fuel or, looked at another way,
how little you can get away with on a
fixed distance. However,
occasionally you must hold, and the
question of how long you can stay
airborne arises, namely endurance.
Speed
Peculiar to landing is speed—a
higher one than specified naturally
requires a longer distance, not only
for slowing down, but the FAA have
also determined that being 5 knots
too fast over the threshold is the
equivalent of being 50 feet too high.
Miscellaneous
Low tyre pressures increase distances
required.
V-Speeds
Significant aircraft speeds:
Speed Meaning
VNE Never Exceed speed, around
90% of Dive Speed (VD). On a
turbine, the equivalent is VMO
or MMO.
VNO Normal Operations
VTOS In a single, a target speed to
be achieved when becoming
airborne. It allows safe control
with a margin over stalling
speed of at least 20%.
VA Manoeuvring speed. The
maximum speed you can
make abrupt, full scale
deflections of the controls
without damage (about twice
VS). Not always the best speed
for entering turbulence (see
below). Valid only at gross
weight. A 20% decrease in
weight needs a 10% reduction
in manoeuvring speed.
VF Flap Speed
VFE Max speed flaps extended
VFO Max flap operating speed
VH Max level speed at max
continuous power.
Flight Planning 167
Speed Meaning
VLE Max speed, gear extended
VLO Max gear operating speed
VLOF Lift off speed
VMCA Minimum Control Speed, for
control in the air, with critical
engine out and the other at
takeoff thrust.
VS Stall speed, or min steady
controllable speed in flight.
VSL As above, for a specific
configuration
VSI Stall speed, clean, power off
VSO Stall Speed in landing config.
V2 Takeoff Safety Speed, or
minimum safe flying speed if
you lose an engine after
takeoff, to be achieved before
screen height (35'). Must be at
least 20% more than stall
speed and 10% above VMC.
Weight is the main factor.
Should be calculated for each
landing for go-arounds.
VX Best angle of climb
VY Best rate of climb
VYSE Best s/e rate of climb
Charts
These may look complicated, but
once you've figured out the way to
enter a performance chart, it
becomes considerably easier. For
exam purposes, the best tip is to
read the small print around the
graph itself, as this is where you will
find the conditions on which the
chart is based, such as "generator
off", or "ant-icing on".
Sometimes, the "chart" is not a chart
at all, but a series of tabulated figures
that require interpolation.
Height/Velocity Curve
Otherwise known as the Dead Man's
Curve, this is a chart for helicopters
that compares speeds against heights
to give you an idea of where not to
be if you want to make a successful
recovery from an engine failure, that
is, you don't want to be at high
altitudes with low speeds, or low
ones with high speeds, so the best
place to be is in the gap between the
shaded areas (see overleaf):
In other words, the graph shows
combinations of speed and height
that the average pilot would find it
impossible to make a safe emergency
landing from. To give the average
pilot more of a chance, a one-second
delay is factored in for minimum
skill levels.
A couple of points to note first of
all: one is that you should check to
see if the chart is in the Limitations or
Performance section of the Flight
Manual. If it's in the latter, its
requirements are recommended, not
mandatory. In some circumstances,
it is more dangerous to try to avoid
the curve, especially if you might
only be in it for a few seconds (as
when getting out of a confined area,
for example).
168 JAR Private Pilot Studies
Anyhow, the vertical shaded area in
the diagram above is called the low
speed section, which is actually split in
two parts at the knee of the curve,
although it's never shown (the knee
is the furthest point at which the
curve extends). The lower portion is
for takeoff power (no intervention),
and the upper portion is for level
flight (cruise power, hand not
necessarily near the collective, so one
second allowed for intervention
time), and the whole area will
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