Helicopters are capable of landing in places inaccessi-
ble to other aircraft. In addition to rooftops, mountain
tops, pinnacles, and other unprepared locations, there
are times when a pilot may have to operate a helicopter
in areas that do not offer a solid place to land. For those
operations, the normal skid gear configuration can be
replaced with a set of floats for water operations or skis
for winter operations.
Note: In this chapter, it is assumed that the helicopter
has a counterclockwise main rotor blade rotation as
viewed from above.
FLOAT EQUIPPED HELICOPTERS
Unlike airplanes, there is no additional rating required
for helicopter float operations. However, it is strongly
recommended that pilots seek instruction from a
qualified instructor prior to operating a float equipped
helicopter. Check the Pilot’s Operating Handbook
(POH) or Rotorcraft Flight Manual (RFM) for any
limitations that may apply when operating with floats
installed. [Figure 9-1]
CONSTRUCTION AND MAINTENANCE
Helicopter floats are constructed of a rubberized
fabric, or nylon coated with neoprene or urethane, and
may be of the fixed utility or emergency pop-out type.
Fixed utility floats typically consist of two floats that
may have one or more individual compartments
inflated with air. Fixed floats may be of the skid-on-
float or the float-on-skid design. [Figure 9-2]
skid-on-float
landing gear has no rigid structure in
or around the float. The float rests on the hard surface
and supports the weight of the helicopter. With this
type of design, be aware of differences in float pres-
sure. While the pressures are usually low, a substantial
difference can cause the helicopter to lean while on a
hard surface making it more susceptible to dynamic
rollover.
float-on-skid
landing gear has modified skids that
support the weight of the helicopter on hard surfaces.
The floats are attached to the top of the skid and only
support the weight of the helicopter in water. A float
with low pressure or one that is completely deflated
will not cause any stability problems on a hard surface.
Emergency
pop-out floats
consist of two or more
floats with one or more individual compartments per
float, depending on the size of the helicopter. [Figure
9-3] They are often inflated with compressed nitrogen
Figure 9-1. Float equipped helicopter.
Figure 9-2. Skid-on-float and float-on-skid landing gear.
Figure 9-3. Pop-out float equipped helicopter.
Ch 09.qxd 8/25/04 11:32 AM Page 9-1
or helium and are deployed prior to an emergency
landing on water. The aircraft’s maintenance manual
states that the pop-out floats must be tested periodically
through a deployment check, a leak check, and a hydro-
static check of the compressed gas cylinder.
To maintain the floats in good condition, perform the
following tasks before and after every flight:
• Inflation —Check each float compartment for
proper inflation. Record the pressure to obtain a
trend over time to help recognize leaks.
• Condition—Inspect the entire float assembly for
cuts, tears, condition of chafing strips, and
security of all components.
• Clean—Wash oil, grease, or gasoline from the
floats, since they deteriorate the float’s material.
•F lush—If the helicopter has been operated on
salt water, flush the entire helicopter, including
the float assembly, with plenty of fresh water.
•S t o rage—Avoid placing the floats in direct
sunlight when not in use.
OPERATIONAL CONSIDERATIONS
Helicopter floats have only a mild effect on aircraft
performance, with just a slight weight penalty and
reduction in cruise speed. However, the large surface
area of the floats makes the helicopter very sensitive to
any departure from coordinated flight. For example, in
cruise flight, any yawing causes the helicopter to roll in
the opposite direction, as shown in figure 9-4. A failure
of the engine requires immediate pedal application to
prevent an uncontrollable yaw, with a resulting roll.
Similarly, a tail rotor failure in cruise flight requires
immediate entry into autorotation to prevent a yaw and
the subsequent roll. Corrections to this rolling moment
can exceed rotor limits and cause mast bumping or
droop stop pounding.
Helicopters equipped with skids-on-floats are limited
in ground operations. Minimize horizontal movement
during takeoffs and landings from hard surfaces to
avoid scuffing or causing other damage to the floats.
Perform approaches, in which hover power may not be
available, by flaring through hovering altitude in a
slightly nose-high attitude to reduce forward motion.
Just prior to the aft portion of the floats touching down,
add sufficient collective pitch to slow the descent and
stop forward motion. Rotate the cyclic forward to level
the helicopter, and allow the helicopter to settle to the
ground, then reduce collective pitch to the full down
position. In helicopters with low inertia rotor systems,
an autorotation to a hard surface requires a more
aggressive flare to a near-zero groundspeed to ensure
minimal movement upon landing. A running takeoff or
landing on a hard surface is not recommended in
helicopters equipped with skids-on-floats.
Helicopters equipped with floats-on-skids are capable
of performing running takeoffs and landings, and
autorotations to hard surfaces require the same
procedures as non-float equipped helicopters. The
surfaces should be flat and clear of objects that may
puncture, rip, or cause other damage to the floats. Do
not attempt to land on the heels of floats-on-skids as
they may cause the tail boom to kick up and be struck
by the rotor.
Helicopters equipped with stored emergency pop-out
floats are operated with the same procedures as a
helicopter without floats. When emergency floats are
deployed, the helicopter may have similar characteris-
tics to a helicopter with fixed floats and should be
flown accordingly. If emergency floats are deployed
during autorotation, the increased surface increases
parasite drag with a resulting reduction in airspeed. To
regain the recommended autorotation airspeed, the
nose must be lowered.
Effects on aircraft performance must also be consid-
ered during water operations. Air is often cooler near
bodies of water, thus decreasing the density altitude but
also increasing humidity. Although the higher humidity
of the air has little effect on aerodynamic performance,
it can reduce piston engine output by more then 10
percent. Properly leaning the mixture might possibly
return some of this lost power.
Turbine engines experience only a small, often negligi-
ble, power loss in high humidity conditions.
Right
Roll
Yaw
Left
Intended Flightpath
Figure 9-4. Float instability.
Ch 09.qxd 8/25/04 11:32 AM Page 9-2
STARTING
A helicopter on a hard surface has the friction of the
skids or floats to counter the torque produced when
the rotor is engaged. Therefore, you have more control
over the helicopter if you can engage the rotors while
it is sitting on a hard surface. On water, little or no anti-
torque control is present until the rotor system has
accelerated to approximately 50 percent of its normal
operating r.p.m. A heavily loaded helicopter’s floats
sit deeper in the water and create more resistance to
the turning force than a lightly loaded helicopter. Thus
a helicopter turns less when heavily loaded and more
when lightly loaded.
To overcome the spinning and to prevent drifting, tie
the helicopter securely to a dock or to the shore using
the fore and aft cross tubes if not otherwise indicated
in the POH or RFM. If help is not available for casting
off, it may be necessary to paddle to a clear location
well away from the shoreline for a safe start. Wind
and water currents may cause the helicopter to turn or
drift a considerable distance before control is obtained.
To compensate, use a starting position upwind and
upcurrent of a clear area.
Illusions of movement or non-movement can make it
difficult to maintain a fixed position during rotor
engagement and runup. Techniques to overcome these
illusions are discussed later.
TAXIING AND HOVERING
Where possible, it is usually more convenient and
safer to hover taxi to the destination. However, due to
power limits, local restrictions, noise, water spray, or
creating a hazard to other vessels or people, it may be
necessary to water taxi the helicopter. To taxi in water,
maintain full rotor r.p.m. and use sufficient up collec-
tive to provide responsive cyclic control to move the
helicopter. Never bottom the collective pitch while the
helicopter is in motion to avoid momentarily sinking
the floats or capsizing the helicopter. Float equipped
helicopters should be taxied with the nose in the
direction of movement. Maximum taxi speed is
attained when the bow wave around the nose of the
floats rises slightly above the normal waterline.
Beyond this speed, the bow wave flows over the front
portion of the floats, and this severe drag may capsize
the helicopter. When the helicopter is heavily loaded,
it is restricted to a slower taxiing speed than when
lightly loaded.When taxiing in small waves, point the
helicopter into or at a slight angle to the waves. Never
allow the helicopter to roll in the trough. In some
instances, increasing collective can produce enough
downwash to create a slight smoothing effect on wind-
produced waves.
A ground swell can be dangerous to the tail rotor while
the helicopter is riding up and pitching over the swell.
Warning: During water operation, if there is any
possibility that the tail rotor struck the water, do not
attempt a takeoff. Although a tail rotor water strike
may not show any visible evidence of damage, a tail
rotor failure is likely to occur.
PREFLIGHT INSPECTION
The preflight inspection consists of the standard
aircraft inspection with a few additional items
associated with the floats. When performing a preflight
inspection, follow the manufacturer’s recommenda-
tions. A typical inspection of the floats includes:
•V isual Inspection—Examine the floats for cuts,
abrasions, or other damage.
• Inflation Check—Although proper inflation can
be checked by hand feeling for equal pressure
and firmness, a pressure gauge is the preferred
method to check for the correct pressure listed in
the POH or RFM. For flights to higher altitudes,
adjust float pressure before takeoff so that
maximum pressure is not exceeded, unless the
floats are equipped with pressure relief valves.
•V alve Checks —Check the air valves by filling
the neck with water and watching for bubbles.
Examine fittings for security and, if operated in
salt water, inspect for corrosion.
• Float Stabilizer, if equipped—Examine the float
stabilizer and other float related surfaces for
security and condition. Any indication of water
contact requires, at a minimum, a visual inspec-
tion of the tail surfaces, tail boom, and mounts.
Consult the aircraft’s maintenance manual for
any additional required inspections.
• Float and Skid Freedom—In cold weather, it is
common for floats and skids to freeze to the
surface. Inspect the floats and skids for freedom
of movement and obstructions. To help prevent
this problem, try to park on a dry surface with
proper drainage.
•S ecure—Ensure all equipment is secure and
properly stowed including survival equipment,
anchors, tiedowns, and paddles. If possible, stow
items inside the helicopter that could become
loose and fly into the rotors.
• Survival Equipment —Check the quantity and
condition of survival equipment including flota-
tion devices, liferafts, provisions, and signaling
devices.
Ch 09.qxd 8/25/04 11:32 AM Page 9-3
Approach the swell at a 30º to 45º angle and use collec-
tive pitch to minimize bobbing. If it becomes obvious
that continued water taxi could lead to a serious
problem, lift the helicopter off and reassess the
situation. It might be possible to land in an area that
does not contain the same conditions.
When hovering over or taxiing on water, movement of
the helicopter may be difficult to judge. The rippling
effect of the water from the downwash makes it appear
as if the helicopter is moving in one direction when it is
in fact stationary or even moving in the opposite
direction. To maintain a fixed position or maintain a
straight course while taxiing and hovering, use a fixed
reference such as the bank or a stationary object in the
water. When reference points are not available, judge
movement by swirls, burbles, or slicks seen around the
floats.
Hovering a helicopter over open water can create
deceptive sensations. Without a reference point,
extensive or rapid helicopter movements may go
unnoticed. Very smooth and very rough water
aggravate this situation. The most desirable water
conditions are moderate ripples from a light breeze. An
odd sensation, similar to vertigo, is sometimes
produced by the concentric outward ripples resulting
from the rotorwash, and pilots must keep their eyes
moving and avoid staring at any particular spot. The
inexperienced pilot may choose to initiate a slight
forward movement when taking off into or landing
from a hover. This guards against undesirable
backward or sideward drift during takeoff or landing.
With smooth water conditions, the usual tendency is to
hover too high because the outward-flowing ripples
from the rotorwash gives the pilot the sensation of
being in a bowl and descending.
TAKEOFF
A float equipped helicopter can perform a normal
takeoff from a hover or directly from the water. If there
is insufficient power available for a normal takeoff, a
running takeoff from a slow forward taxi may be an
option. However, remember that water creates drag, so
with insufficient power, a running takeoff may not be
possible either.
The preferred method for taking off from water is to
move forward into translational lift without pausing to
hover after leaving the water. This type of takeoff is
similar to a normal takeoff from the surface.
A normal takeoff from a hover over water is similar to
the same type of takeoff over a hard surface. A
common problem is poor judgment of altitude and rate
of acceleration, which causes the pilot to increase speed
without an increase in altitude. This causes the
helicopter to enter the high speed portion of the
height/velocity diagram, reducing the probability of a
successful autorotation in the event of an engine
failure. Also, be aware of possible restricted visibility
during takeoff from water spray produced by the
rotors. To help alleviate these problem areas, as the
helicopter begins to move forward, use reference
points some distance in front of the helicopter.
Over water, ground effect is reduced from the absorp-
tion of energy in the downwash. This increases the
power required to hover and with other factors may
exceed the power available. When this occurs, perform
a slow taxi to a takeoff to take advantage of the
translational lift produced from the forward motion.
Remember, translational lift is also affected by any
wind that is present. Apply sufficient collective pitch
to keep the floats riding high or skimming the surface.
While skimming the surface, float drag increases
rapidly, and the takeoff must be executed promptly
since a further increase in speed, with the floats
plowing in the water, is likely to exceed the limit of aft
cyclic control or cause the floats to tuck under the
water. The speed at which the floats tuck under is the
maximum forward speed that can be attained and is
determined by the load and attitude of the helicopter.
Never lower the collective during this procedure
because doing so could bury the nose of the floats in
the water and possibly capsize the helicopter.
LANDING
Pilots performing glassy water landings may experi-
ence some difficulty in determining their altitude
above the surface. The recommended procedure is to
continue an approach to the surface with a slow rate of
descent until making contact, avoiding any attempt to
hover. The helicopter’s downwash creates a
disturbance in the water as concentric ripples moving
away from the helicopter. Although this provides the
pilot with a visual reference, it may also cause the
sensation of moving backwards or descending rapidly.
A natural tendency is to apply too much collective
pitch in an attempt to halt the perceived descent. To
overcome the effects of these visual illusions, avoid
staring at the water near the helicopter and maintain
forward and downward movement until contacting the
water. When making approaches to a landing on a
large body of water when land areas or other fixed
objects are not visible, occasionally glance to either
side of the horizon to avoid stare-fixation. Another
technique some pilots use when fixed objects are not
available, and the water is glassy, is to make a low pass
over the area to create a disturbance on the surface.
This disturbance remains for a while giving the pilot a
reference to help determine distance.
When landing on water with a slight chop, bring the
helicopter to a hover and descend vertically with no
Ch 09.qxd 8/25/04 11:32 AM Page 9-4
horizontal movement. This procedure is similar to
landing on a hard surface.
Make a running landing on water when high density
altitude or a heavy load results in insufficient power to
hover. Perform this type of landing when sufficient
power is not available to reduce the speed to 5 knots or
less. When approaching with greater than 5 knots of
speed, hold a slight nose-high attitude to allow the aft
portion of the floats to plane. Maintain collective pitch
until the speed reduces to below 5 knots, and the heli-
copter settles into the water. At zero groundspeed,
slowly lower the collective into the full down position.
Lowering the collective or leveling the helicopter too
quickly may result in the floats tucking, which can
cause the helicopter to capsize.
Caution: The following discussion deals with land-
ing in heavy seas. Use these procedures only in an
emergency.
Landing the float helicopter becomes risky when the
height of short, choppy waves exceed one half the
distance from the water to the helicopter’s stinger, and
the distance from crest to crest is nearly equal to or less
than the length of the helicopter. These waves cause
the helicopter to pitch rapidly and may bring the rotor
blades in contact with the tail boom or the tail rotor in
contact with the water. In addition, avoid landing
parallel to steep swells as this could lead to dynamic
rollover. [Figure 9-5]
If landing on waves higher than half the distance from
water to stinger, the following techniques apply:
• Land the helicopter 30º to 45º from the direct
heading into the swell. This minimizes the fore
and aft pitching of the fuselage, reducing the
possibility of the main rotor striking the tail
boom, or the tail rotor contacting the water. This
also minimizes the possibility of dynamic
rollover.
Perpendicular to Swell
Parallel to Swell
Angled 30° to 45°
to Swell
Rotor Strikes
Tail Boom
Dynamic
Rollover
Tail Rotor
Strikes Water
Figure 9-5. Effect of landing heading relative to waves.
Ch 09.qxd 8/25/04 11:32 AM Page 9-5
• When landing with power, maintain rotor r.p.m. in
the normal operating range. This permits a quick
takeoff if the helicopter begins to pitch exces-
sively or when an especially high wave becomes
a hazard.
• When landing without power in high wave
conditions, hold the desired heading as long as
directional control permits. As the rotor r.p.m.
decreases to the point that the desired heading
cannot be maintained, bring the rotor to a stop as
quickly as possible to avoid rotor contact with the
tail boom.
AUTOROTATION
An autorotation to water is similar to one performed on
a hard surface except that during touchdown, the
helicopter is kept in a slight nose-high position. For
greater safety, slow to around 5 knots of forward speed.
However, if this is not possible, maintain a slight
nose-high attitude and full-up collective to allow the
floats to plane until the speed decelerates below 5
knots. As the helicopter settles to the surface and slows
to zero knots, level the helicopter with cyclic and lower
the collective. Do not lower the collective or level the
helicopter until the speed has reduced sufficiently or
the floats may tuck causing the helicopter to capsize.
Hold a pitch attitude that keeps the tail from contacting
the water.
Autorotations to smooth, glassy water may lead to
depth perception problems. If possible, try to land near
a shoreline or some object in the water. This helps in
judging altitude just prior to touchdown.
SHUTDOWN AND MOORING
Although a helicopter can be moored prior to
shutdown, it is preferable to fly to a landing spot on the
dock or shore prior to shutting down. The helicopter
can then be parked there. If mooring is the only option,
be aware of any posts or pillars that might extend above
the main dock level. Even though there may be plenty
of blade clearance when the rotor is at full r.p.m., blade
droop due to low r.p.m. could cause the blades to come
into contact with items on the dock. Also be aware of
wind and waves that could tilt the helicopter and cause
the blades to contact objects. If near an ocean or large
body of water, tides could change the water level
considerably in just a few hours, so anticipate any
changes and position the helicopter to prevent any
damage due to the changing conditions.
When mooring the helicopter prior to shutting down,
arrange the mooring lines so the tail cannot swing into
objects once the rotors stop. Some pilots prefer to moor
the helicopter nose in to protect the tail rotor.
If there is sufficient room to allow for drift and
possible turning or weathervaning, the helicopter may
be shut down on open water, but wind and water cur-
rents may move the helicopter a considerable distance.
When shutting down on open water, do so upwind or
upcurrent and allow the helicopter to drift to the moor-
ing buoy or dock. It might be necessary to use a paddle
to properly position the helicopter.
Because of the great danger from the main rotor or tail
rotor of the helicopter to personnel, docks, or vessels,
pilots should never attempt to water taxi up to a dock
or vessel. In addition, loading or unloading passengers
or freight from a partially afloat helicopter with the
rotors turning is extremely dangerous. When loading
or unloading passengers, the helicopter should be
resting on a hard surface, either on the shore or on a
helipad on a dock or on a boat. Passengers should
always:
• stay away from the rear of the helicopter,
• approach or leave the helicopter in a crouching
manner,
• approach from the side or front, but never out of
the pilot’s line of vision,
• hold firmly to loose articles and never chase
after articles that are blown away by the rotor
downwash, and
• never grope or feel their way toward or away
from the helicopter.
GROUND HANDLING
On helicopters equipped with floats-on-skids, ground
handling usually can be performed with normal or
slightly modified ground handling wheels. With the
ground handling wheels kept onboard, the helicopter
can be handled at any landing facility. On helicopters
equipped with skids-on-floats, the helicopter must be
transported by a special dolly or wheeled platform on
which the helicopter lands. Unless a dolly or platform
is available at the destination, the aircraft usually
remains where it lands.
SKI EQUIPPED HELICOPTERS
Ski equipped helicopters are capable of operating from
snow and other soft surfaces that might otherwise
inhibit conventional gear helicopters. [Figure 9-6]
Snow can greatly reduce visibility causing pilot disori-
entation; therefore, special procedures are used when
operating in snow.
Ch 09.qxd 8/25/04 11:32 AM Page 9-6
CONSTRUCTION AND MAINTENANCE
REQUIREMENTS
Helicopter skis are made from plastics and composite
materials such as fiberglass with steel and aluminum
hardware. Steel runners on the bottoms of the skis
protect them during hard surface operations.
Excessive wear of these runners can lead to wear or
damage to the skis.
All of the steel bands securing the skis to the skids
should have a protective rubber lining preventing the
bands from wearing into the skids. This lining should
be replaced if it becomes brittle or shows signs of
wear.
Have any damage to the skis repaired before flight
even if the skis are not needed, or simply have the skis
removed. A cracked ski could break off and damage
the helicopter or injure people on the ground.
OPERATIONAL CHARACTERISTICS
Apart from the small weight penalty and slight reduc-
tion in speed, a ski equipped helicopter operates
exactly like one with no skis. The main concern when
operating with skis is to avoid operations that may
damage the skis, such as landing on rocks or rough
hard surfaces.
PREFLIGHT REQUIREMENTS
The preflight inspection consists of the standard
aircraft inspection and includes additional items asso-
ciated with the skis. The POH or RFM contains the
appropriate supplements and additional inspection
criteria. Typical inspection criteria include:
• Hardware—Inspect all of the steel bands and
bolts securing the skis to the skids for security.
Check for any movement of the skis on the skids.
A torque stripe can help determine if any move-
ment has occurred.
• Liner—Inspect the rubber liner between the
steel bands and the skids.
• Runners —Inspect the steel runners on the
bottoms of the skis.
• Condition —Inspect the skis for cracks and
check the edges for separation of fiber layers.
• Clean—Remove all snow and ice from the skis
which could break off and cause damage to the
tail rotor during flight.
• Ski Freedom—In cold weather, it is common for
the skis to freeze to the surface. Inspect the skis
for freedom of movement.
STARTING
Helicopter starting procedures on snow and ice are
identical to a hard surface starting procedure except
that care must be taken to maintain antitorque control
on a slippery surface. When performing the
free-wheeling unit check on ice, place the pedals in the
autorotation position to prevent the helicopter from
spinning.
TAXIING AND HOVERING
When hovering over snow, the rotorwash may create a
white-out condition if sufficient loose snow is present.
Blowing and drifting snow may give the illusion of
movement in the opposite direction. When operating
in snow, it is vital to select a reference point to
maintain situational awareness and take off directly to
a high hover at an altitude that allows visual contact to
be maintained. When performing a hover taxi, select
the speed just above effective translational lift to help
keep the blowing snow behind the helicopter. If loose
snow is less than 6 inches, it may be possible to apply
collective pitch to create enough rotorwash to blow
away the majority of the snow before lift-off. If
moving the helicopter a short distance, and especially
when around other aircraft, it might be preferable to
surface taxi on the skis.
When taxiing wheel-equipped helicopters on snow and
ice, use caution when applying the brakes. If the
helicopter begins to skid sideways, lower the
collective, which places all of the weight on the wheels
and move the cyclic in the opposite direction of the
skid. If the skid continues, the best option at that point
is to bring the helicopter into a hover, but be aware of
objects that could lead to a dynamic rollover situation.
TAKEOFF
Normal takeoff procedures are used in snow and ice,
but before startup, check the departure path for any
obstructions that may be obscured by blowing snow.
Powerlines are difficult to see in the best conditions
and nearly impossible to recognize through blowing
snow.
Perform a takeoff from a hover or from the surface by
fairly quickly increasing speed through effective
translational lift and gaining altitude in order to fly out
Figure 9-6. Ski equipped helicopter.
Ch 09.qxd 8/25/04 11:32 AM Page 9-7
of the low visibility conditions. A takeoff from ice
requires slow application of power and proper pedal
application to prevent spinning. At certain tempera-
tures, the skis may freeze to ice surfaces. If this occurs,
a slight left and right yawing with the pedals may break
the helicopter free. If this does not free the skids, shut
down the helicopter and free them manually. Excessive
pedal application could damage the skids.
LANDING
As with takeoffs, landings in snow can prove to be
extremely hazardous if reference points are not
available. When possible, land near objects that won’t
be easily obscured by blowing snow. If none are
available, drop a marker made from a heavy object,
such as a rock tied to a colored cloth; then retrieve it
after landing.
When the snow condition is loose or unknown, make a
zero-groundspeed landing directly to the surface
without pausing to hover. A shallow approach and
running landing can be performed when the snow is
known to be hard packed and obstacles are not hidden
under the snow. The lower power required in a running
landing reduces the downwash and the forward motion
keeps blowing snow behind the helicopter until after
surface contact.
If the surface conditions are unknown, a low reconnais-
sance flight might be appropriate. This could be
followed by a low pass. A low pass might blow away
loose snow and keep the debris behind the helicopter. If
the surface appears appropriate for a landing, make an
approach to a high hover to blow away any remaining
loose snow and begin a vertical descent to the landing.
If the surface appears to be deep hard-packed snow or
ice, lower the collective slowly on landing and watch
for cracking in the surface. Should one skid break
through the surface, a dynamic rollover is likely to
follow, so be prepared to return to a hover if the
surface is unstable.
Skis are also very useful for landing on uneven or soft,
spongy surfaces. They provide a larger surface area to
support the helicopter, thus assisting in stability. Be
sure that the skis are not hooked under roots or brush
during lift-off.
AUTOROTATION
Use normal autorotation procedures in ski equipped
helicopters. Perform practice autorotations on snow or
sod to reduce the wear on the skis.
GROUND HANDLING
Shut down before loading and unloading. If shutting
down is not feasible, load and unload passengers only
from the front during snow and ice operations. This
prevents the main rotors from striking an individual
should one landing gear drop through the snow or ice.
Beware of loading and unloading while running in
deep snow as the rotor clearance is reduced by the
height of the snow above the skids.
Most skis for skid-equipped helicopters allow use of
standard or slightly modified ground handling wheels.
Skis for wheel-equipped helicopters often have
cutouts to allow the wheels to protrude slightly below
the ski for ground handling.