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These three factors are seldom compatible. When compromises
have to be made, the pilot should aim for a
wind/obstacle/terrain combination that permits a final
approach with some margin for error in judgment or
technique. A pilot who overestimates the gliding range
may be tempted to stretch the glide across obstacles in
the approach path. For this reason, it is sometimes
better to plan the approach over an unobstructed area,
regardless of wind direction. Experience shows that a
collision with obstacles at the end of a ground roll, or
slide, is much less hazardous than striking an obstacle
at flying speed before the touchdown point is reached.
TERRAIN TYPES
Since an emergency landing on suitable terrain resembles
a situation in which the pilot should be familiar
through training, only the more unusual situation will
be discussed.
CONFINED AREAS
The natural preference to set the airplane down on the
ground should not lead to the selection of an open spot
between trees or obstacles where the ground cannot be
reached without making a steep descent.
Once the intended touchdown point is reached, and the
remaining open and unobstructed space is very limited,
it may be better to force the airplane down on the
ground than to delay touchdown until it stalls (settles).
An airplane decelerates faster after it is on the ground
than while airborne. Thought may also be given to the
desirability of ground-looping or retracting the landing
gear in certain conditions.
A river or creek can be an inviting alternative in otherwise
rugged terrain. The pilot should ensure that the
water or creek bed can be reached without snagging
the wings. The same concept applies to road landings
with one additional reason for caution; manmade
obstacles on either side of a road may not be visible
until the final portion of the approach.
When planning the approach across a road, it should
be remembered that most highways, and even rural
dirt roads, are paralleled by power or telephone lines.
Only a sharp lookout for the supporting structures, or
poles, may provide timely warning.
TREES (FOREST)
Although a tree landing is not an attractive prospect,
the following general guidelines will help to make the
experience survivable.
• Use the normal landing configuration (full flaps,
gear down).
• Keep the groundspeed low by heading into the
wind.
• Make contact at minimum indicated airspeed, but
not below stall speed, and “hang” the airplane in
the tree branches in a nose-high landing attitude.
Involving the underside of the fuselage and both
wings in the initial tree contact provides a more
even and positive cushioning effect, while preventing
penetration of the windshield. [Figure
16-4]
• Avoid direct contact of the fuselage with heavy
tree trunks.
• Low, closely spaced trees with wide, dense
crowns (branches) close to the ground are much
better than tall trees with thin tops; the latter
allow too much free fall height. (A free fall from
75 feet results in an impact speed of about 40
knots, or about 4,000 f.p.m.)
• Ideally, initial tree contact should be symmetrical;
that is, both wings should meet equal
resistance in the tree branches. This distribution
of the load helps to maintain proper airplane
attitude. It may also preclude the loss of one
wing, which invariably leads to a more rapid and
less predictable descent to the ground.
• If heavy tree trunk contact is unavoidable once
the airplane is on the ground, it is best to involve
both wings simultaneously by directing the airplane
between two properly spaced trees. Do not
attempt this maneuver, however, while still
airborne.
WATER (DITCHING) AND SNOW
A well-executed water landing normally involves less
deceleration violence than a poor tree landing or a
Ch 16.qxd 5/7/04 10:30 AM Page 16-4
16-5
touchdown on extremely rough terrain. Also an
airplane that is ditched at minimum speed and in a normal
landing attitude will not immediately sink upon
touchdown. Intact wings and fuel tanks (especially
when empty) provide floatation for at least several
minutes even if the cockpit may be just below the
water line in a high-wing airplane.
Loss of depth perception may occur when landing on a
wide expanse of smooth water, with the risk of flying
into the water or stalling in from excessive altitude. To
avoid this hazard, the airplane should be “dragged in”
when possible. Use no more than intermediate flaps on
low-wing airplanes. The water resistance of fully
　
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