faa-h-8083-3a-7of7, FSX, FAA
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Ch 16.qxd 5/7/04 10:30 AM Page 16-1
E
MERGENCY SITUATIONS
This chapter contains information on dealing with
non-normal and emergency situations that may occur in
flight. The key to successful management of an
emergency situation, and/or preventing a non-normal
situation from progressing into a true emergency, is
a thorough familiarity with, and adherence to, the
procedures developed by the airplane manufacturer and
contained in the FAA-approved Airplane Flight Manual
and/or Pilot’s Operating Handbook (AFM/POH). The
following guidelines are generic and are
not
meant to
replace the airplane manufacturer’s recommended
procedures. Rather, they are meant to enhance the
pilot’s general knowledge in the area of non-normal and
emergency operations. If any of the guidance in this
chapter conflicts in any way with the manufacturer’s
recommended procedures for a particular make and
model airplane,
the manufacturer’s recommended
procedures take precedence.
A precautionary landing, generally, is less hazardous
than a forced landing because the pilot has more time
for terrain selection and the planning of the approach.
In addition, the pilot can use power to compensate for
errors in judgment or technique. The pilot should be
aware that too many situations calling for a precaution-
ary landing are allowed to develop into immediate
forced landings, when the pilot uses wishful thinking
instead of reason, especially when dealing with a
self-inflicted predicament. The non-instrument rated
pilot trapped by weather, or the pilot facing imminent
fuel exhaustion who does not give any thought to the
feasibility of a precautionary landing accepts an
extremely hazardous alternative.
PSYCHOLOGICAL HAZARDS
There are several factors that may interfere with a
pilot’s ability to act promptly and properly when faced
with an emergency.
•
E
MERGENCY LANDINGS
This section contains information on emergency land-
ing techniques in small fixed-wing airplanes. The
guidelines that are presented apply to the more adverse
terrain conditions for which no practical training is
possible. The objective is to instill in the pilot the
knowledge that almost any terrain can be considered
“suitable” for a survivable crash landing if the pilot
knows how to use the airplane structure for self-protection
and the protection of passengers.
Reluctance to accept the emergency situation.
A pilot who allows the mind to become paralyzed
at the thought that the airplane will be on the
ground, in a very short time, regardless of the
pilot’s actions or hopes, is severely handicapped
in the handling of the emergency. An unconscious
desire to delay the dreaded moment may lead to
such errors as: failure to lower the nose to main-
tain flying speed, delay in the selection of the
most suitable landing area within reach, and
indecision in general. Desperate attempts to
correct whatever went wrong, at the expense of
airplane control, fall into the same category.
TYPES OF EMERGENCY LANDINGS
The different types of emergency landings are defined
as follows.
•
esire to save the airplane.
The pilot who has
been conditioned during training to expect to find
a relatively safe landing area, whenever the flight
instructor closed the throttle for a simulated
forced landing, may ignore all basic rules of
airmanship to avoid a touchdown in terrain where
airplane damage is unavoidable. Typical con-
sequences are: making a 180° turn back to the
runway when available altitude is insufficient;
stretching the glide without regard for minimum
control speed in order to reach a more appealing
field; accepting an approach and touchdown
situation that leaves no margin for error. The
desire to save the airplane, regardless of the risks
involved, may be influenced by two other factors:
the pilot’s financial stake in the airplane and the
•
orced landing.
An immediate landing, on or off
an airport, necessitated by the inability to con-
tinue further flight. A typical example of which is
an airplane forced down by engine failure.
•
ecautionary landing.
A premeditated landing,
on or off an airport, when further flight is possi-
ble but inadvisable. Examples of conditions that
may call for a precautionary landing include
deteriorating weather, being lost, fuel shortage,
and gradually developing engine trouble.
•
Ditching.
A forced or precautionary landing on
water.
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certainty that an undamaged airplane implies no
bodily harm. There are times, however, when a
pilot should be more interested in sacrificing the
airplane so that the occupants can safely walk
away from it.
•
Undue concern about getting hurt.
Fear is a
vital part of the self-preservation mechanism.
However, when fear leads to panic, we invite that
which we want most to avoid. The survival
records favor pilots who maintain their compo-
sure and know how to apply the general concepts
and procedures that have been developed through
the years. The success of an emergency landing is
as much a matter of the mind as of skills.
Figure 16-1. Using vegetation to absorb energy.
B
ASIC SAFETY CONCEPTS
plan the touchdown in such a manner that only non-
essential structure is “used up” in the principal
slowing down process.
GENERAL
A pilot who is faced with an emergency landing in ter-
rain that makes extensive airplane damage inevitable
should keep in mind that the avoidance of crash
injuries is largely a matter of: (1) keeping vital
structure (cockpit/cabin area) relatively intact by using
dispensable structure (such as wings, landing gear, and
fuselage bottom) to absorb the violence of the stopping
process before it affects the occupants, (2) avoiding
forceful bodily contact with interior structure.
The overall severity of a deceleration process is
governed by speed (groundspeed) and stopping
distance. The most critical of these is speed; doubling
the groundspeed means quadrupling the total destruc-
tive energy, and vice versa. Even a small change in
groundspeed at touchdown—be it as a result of wind
or pilot technique—will affect the outcome of a
controlled crash. It is important that the actual
touchdown during an emergency landing be made at
the lowest possible
controllable
airspeed, using all
available aerodynamic devices.
The advantage of sacrificing dispensable structure is
demonstrated daily on the highways. A head-on car
impact against a tree at 20 miles per hour (m.p.h.) is
less hazardous for a properly restrained driver than a
similar impact against the driver’s door. Accident
experience shows that the extent of crushable structure
between the occupants and the principal point of
impact on the airplane has a direct bearing on the
severity of the transmitted crash forces and, therefore,
on survivability.
Most pilots will instinctively
—
and correctly—look
for the largest available flat and open field for an emer-
gency landing. Actually, very little stopping distance
is required if the speed can be dissipated uniformly;
that is, if the deceleration forces can be spread evenly
over the available distance. This concept is designed
into the arresting gear of aircraft carriers that provides
a nearly constant stopping force from the moment of
hookup.
Avoiding forcible contact with interior structure is a
matter of seat and body security. Unless the occupant
decelerates at the same rate as the surrounding
structure, no benefit will be realized from its relative
intactness. The occupant will be brought to a stop vio-
lently in the form of a secondary collision.
The typical light airplane is designed to provide
protection in crash landings that expose the occupants
to nine times the acceleration of gravity (9 G) in a
forward direction. Assuming a uniform 9 G decelera-
tion, at 50 m.p.h. the required stopping distance is
about 9.4 feet. While at 100 m.p.h. the stopping dis-
tance is about 37.6 feet
—
about four times as great.
[Figure 16-2] Although these figures are based on an
ideal deceleration process, it is interesting to note what
can be accomplished in an effectively used short stop-
ping distance. Understanding the need for a firm
but uniform deceleration process in very poor terrain
enables the pilot to select touchdown conditions that
will spread the breakup of dispensable structure over a
short distance, thereby reducing the peak deceleration
of the cockpit/cabin area.
Dispensable airplane structure is not the only available
energy absorbing medium in an emergency situation.
Vegetation, trees, and even manmade structures may
be used for this purpose. Cultivated fields with dense
crops, such as mature corn and grain, are almost as
effective in bringing an airplane to a stop with
repairable damage as an emergency arresting device
on a runway. [Figure 16-1] Brush and small trees
provide considerable cushioning and braking effect
without destroying the airplane. When dealing with
natural and manmade obstacles with greater strength
than the dispensable airplane structure, the pilot must
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9g Deceleration
The only time the pilot has a very limited choice is dur-
ing the low and slow portion of the takeoff. However,
even under these conditions, the ability to change the
impact heading only a few degrees may ensure a
survivable crash.
37.6 ft.
If beyond gliding distance of a suitable open area, the
pilot should judge the available terrain for its energy
absorbing capability. If the emergency starts at a
considerable height above the ground, the pilot should
be more concerned about first selecting the desired
general area than a specific spot. Terrain appearances
from altitude can be very misleading and considerable
altitude may be lost before the best spot can be
pinpointed. For this reason, the pilot should not
hesitate to discard the original plan for one that is obvi-
ously better. However, as a general rule, the pilot
should not change his or her mind more than once; a
well-executed crash landing in poor terrain can be less
hazardous than an uncontrolled touchdown on an
established field.
9.4 ft.
50 m.p.h. 100 m.p.h.
Figure 16-2. Stopping distance vs. groundspeed.
ATTITUDE AND SINK RATE CONTROL
The most critical and often the most inexcusable error
that can be made in the planning and execution of an
emergency landing, even in ideal terrain, is the loss of
initiative over the airplane’s attitude and sink rate at
touchdown. When the touchdown is made on flat, open
terrain, an excessive nose-low pitch attitude brings the
risk of “sticking” the nose in the ground. Steep bank
angles just before touchdown should also be avoided,
as they increase the stalling speed and the likelihood of
a wingtip strike.
AIRPLANE CONFIGURATION
Since flaps improve maneuverability at slow speed,
and lower the stalling speed, their use during final
approach is recommended when time and circum-
stances permit. However, the associated increase in
drag and decrease in gliding distance call for caution in
the timing and the extent of their application;
premature use of flap, and dissipation of altitude,
may jeopardize an otherwise sound plan.
A hard and fast rule concerning the position of a
retractable landing gear at touchdown cannot be given.
In rugged terrain and trees, or during impacts at high
sink rate, an extended gear would definitely have a
protective effect on the cockpit/cabin area. However,
this advantage has to be weighed against the possible
side effects of a collapsing gear, such as a ruptured fuel
tank. As always, the manufacturer’s recommendations
as outlined in the AFM/POH should be followed.
Since the airplane’s vertical compone
nt of velocity will
be immediately reduced to zero upon ground contact, it
must be kept well under control. A flat touchdown at a
high sink rate (well in excess of 500 feet per minute
(f.p.m.)) on a hard surface can be injurious without
destroying the cockpit/cabin structure, especially during
gear up landings in low-wing airplanes. A rigid bottom
construction of these airplanes may preclude adequate
cushioning by structural deformation. Similar impact
conditions may cause structural collapse of the overhead
structure in high-wing airplanes. On soft terrain, an
excessive sink rate may cause digging in of the lower
nose structure and severe forward deceleration.
When a normal touchdown is assured, and ample stop-
ping distance is available, a gear up landing on level, but
soft terrain, or across a plowed field, may result in less
airplane damage than a gear down landing. [Figure 16-3]
TERRAIN SELECTION
Apilot’s choice of emergency landing sites is governed
by:
•
The route selected during preflight planning.
•
The height above the ground when the emergency
occurs.
•
Excess airspeed (excess airspeed can be con-
verted into distance and/or altitude).
Figure 16-3. Intentional gear up landing.
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Deactivation of the airplane’s electrical system before
touchdown reduces the likelihood of a post-crash fire.
However, the battery master switch should not be
turned off until the pilot no longer has any need for
electrical power to operate vital airplane systems.
Positive airplane control during the final part of the
approach has priority over all other considerations,
including airplane configuration and cockpit checks.
The pilot should attempt to exploit the power available
from an irregularly running engine; however, it is gen-
erally better to switch the engine and fuel off just
before touchdown. This not only ensures the pilot’s
initiative over the situation, but a cooled down engine
reduces the fire hazard considerably.
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.
•
APPROACH
When the pilot has time to maneuver, the planning of
the approach should be governed by three factors.
•
Wind direction and velocity.
Use the normal landing configuration (full flaps,
gear down).
•
Dimensions and slope of the chosen field.
•
eep the groundspeed low by heading into the
wind.
•
Obstacles in the final approach path.
These three factors are seldom compatible. When com-
promises 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.
T
ERRAIN TYPES
Since an emergency landing on suitable terrain resem-
bles a situation in which the pilot should be familiar
through training, only the more unusual situation will
be discussed.
•
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 pre-
venting penetration of the windshield. [Figure
16-4]
•
void 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 symmet-
rical; 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.
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 lim-
ited, 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.
•
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 air-
plane 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
A river or creek can be an inviting alternative in other-
wise rugged terrain. The pilot should ensure that the
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proper glide attitude, and select a field directly ahead
or slightly to either side of the takeoff path.
Figure 16-4. Tree landing.
The decision to continue straight ahead is often
difficult to make unless the problems involved in
attempting to turn back are seriously considered. In the
first place, the takeoff was in all probability made into
the wind. To get back to the takeoff field, a downwind
turn must be made. This increases the groundspeed and
rushes the pilot even more in the performance of
procedures and in planning the landing approach.
Secondly, the airplane will be losing considerable
altitude during the turn and might still be in a bank
when the ground is contacted, resulting in the airplane
cartwheeling (which would be a catastrophe for the
occupants, as well as the airplane). After turning down-
wind, the apparent increase in groundspeed could
mislead the pilot into attempting to prematurely slow
down the airplane and cause it to stall. On the other
hand, continuing straight ahead or making a slight turn
allows the pilot more time to establish a safe landing
attitude, and the landing can be made as slowly as
possible, but more importantly, the airplane can be
landed while under control.
touchdown on extremely rough terrain. Also an
airplane that is ditched at minimum speed and in a nor-
mal 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.
Concerning the subject of turning back to the runway
following an engine failure on takeoff, the pilot should
determine the minimum altitude an attempt of such a
maneuver should be made in a particular airplane.
Experimentation at a safe altitude should give the pilot
an approximation of height lost in a descending 180°
turn at idle power. By adding a safety factor of about
25 percent, the pilot should arrive at a practical deci-
sion height. The ability to make a 180° turn does not
necessarily mean that the departure runway can be
reached in a power-off glide; this depends on the wind,
the distance traveled during the climb, the height
reached, and the glide distance of the airplane without
power. The pilot should also remember that a turn back
to the departure runway may in fact require more than
a 180° change in direction.
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
extended flaps may result in asymmetrical flap failure
and slowing of the airplane. Keep a retractable gear up
unless the AFM/POH advises otherwise.
A landing in snow should be executed like a ditching,
in the same configuration and with the same regard for
loss of depth perception (white out) in reduced visibil-
ity and on wide open terrain.
Consider the following example of an airplane which
has taken off and climbed to an altitude of 300 feet
AGL when the engine fails. [Figure 16-5 on next
page]. After a typical 4 second reaction time, the pilot
elects to turn back to the runway. Using a standard rate
(3° change in direction per second) turn, it will take 1
minute to turn 180°. At a glide speed of 65 knots, the
radius of the turn is 2,100 feet, so at the completion of
the turn, the airplane will be 4,200 feet to one side of
the runway. The pilot must turn another 45° to head the
airplane toward the runway. By this time the total
change in direction is 225° equating to 75 seconds plus
the 4 second reaction time. If the airplane in a power-
off glide descends at approximately 1,000 f.p.m., it
E
NGINE FAILURE AFTER TAKEOFF
(SINGLE-ENGINE)
The altitude available is, in many ways, the controlling
factor in the successful accomplishment of an emer-
gency landing. If an actual engine failure should occur
immediately after takeoff and before a safe maneuvering
altitude is attained, it is usually inadvisable to attempt
to turn back to the field from where the takeoff was
made. Instead, it is safer to immediately establish the
16-5
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