The engine may heat up considerably during takeoff and climb, and cooling system mismanagement can lead to dangerously
high temperatures in a short time. If the self-launching glider has cowl flaps for cooling, the pilot should set the cowl flaps
for high power operations. In some self-launching gliders, operating at full power with cowl flaps closed can result in
overheating and damage to the engine in as little as 2 minutes. To minimize the chances of engine damage or fire, the pilot
should monitor engine temperatures during high power operations and follow engine operating limitations described in
the GFM/POH. If these measures do not reduce high temperatures and since extended overheating could cause an inflight
fire, the safest course of action may include shutting down the engine and making a precautionary landing. An inflight fire
presents a much greater threat than an emergency landing.
Handling limitations for a given self-launch may include minimum controllable airspeed with power on, minimum
controllable airspeed with power off, and other limitations described in the GFM/POH. Self-launching gliders come in
many configurations. Those with a top-mounted retractable engine and/or propeller have a thrust line above the longitudinal
axis of the glider. Significant power changes may cause substantial pitch attitude changes. For instance, full power setting
in these self-launching gliders introduces a nose-down pitching moment.
To counteract this pitching moment, the pilot normally holds the control stick back and uses trim. If the pilot quickly
reduces from full power to idle power while maintaining significant control-up stick force, the glider tends to pitch up with
the power reduction. This nose-pitching moment could induce a stall. Smooth and coordinated management of power and
flight control provides the safest procedure under these conditions.
During climb-out, the pilot should hold a pitch attitude that results in climbing out at the desired airspeed, while adjusting
elevator trim as necessary. Pilots should manage climbs in self-launching gliders using smooth control inputs and smooth
and gradual throttle adjustments.
When climbing under power, most self-launching gliders exhibit a turning tendency due to P-factor. P-factor results from
uneven distribution of thrust caused by the difference between the angle of attack (AOA) of the ascending propeller blade
and the descending propeller blade. The pilot uses rudder to counteract P-factor during climbs with power. [Figure 7-30]
The red arrow represents P-factor, where the decending
propeller blade in a climb has a greater angle of attack
than the opposite climbing propeller blade, resulting in
more thrust on the right blade than on the left blade.
Without rudder input from the pilot, the glider tends to
turn left during a climb.
P-factor: effects of propeller thrust in a climb
Figure 7-30. P-factor.
The pilot should scan for other aircraft traffic before making any turn. Coordinated aileron and rudder control, as well as
turns made with a shallow bank angle, result in a more efficient flight and faster climb rate.
Detailed engine shutdown procedures are described in the GFM/POH. The manufacturer provides engine cool-down
procedures for reducing engine system temperatures prior to engine shutdown. Lowering the nose to increase airspeed
provides faster flow of cooling air to the engine cooling system, and several minutes of reduced throttle and increased
cooling airflow may allow the engine to reach an appropriate temperature for shutdown.
When preparing to shut down the engine, the pilot should reduce power slowly to reduce or eliminate shock cooling. If
shock cooling occurs, the external parts cool faster and shrink more than the interior components resulting in binding and
scuffing of moving parts such as piston rings and valves while the engine continues to operate.
If the engine retracts, additional time after engine shutdown may reduce engine temperature to acceptable limits prior to
retracting and stowing the engine in the fuselage. Consult the GFM/POH for details.
Retractable-engine self-launching gliders become aerodynamically more efficient after stowing the engine. The alignment
of the propeller blades may need adjustment to prevent interference with the engine bay doors.
When the engine/propeller installation sits aft of the pilot’s head, the gliders may have a mirror that enables the pilot to
perform a visual propeller alignment check prior to stowing the engine/propeller pod. The GFM/POH contains detailed
instructions for stowing the engine and propeller for a particular glider. If a malfunction occurs
during engine shutdown and stowage, the pilot may not be able to stow or extend the engine for restart. In this case,
glide performance will be reduced by as much as 50%. See GFM/POH for specific information. In anticipation of this
eventuality, the pilot should have a landing area within power-off gliding distance.
Some self-launching gliders use a nose-mounted engine/propeller installation that resembles a single-engine airplane. In
these self-launching gliders, the shutdown procedure usually consists of operating the engine for a short time at reduced
power to cool the engine to shutdown temperature. After shutdown, the pilot should close cowl flaps (if installed) to reduce
drag and increase gliding efficiency. The manufacturer may recommend a time interval between engine shutdown and cowl
flap closure to prevent excess temperatures buildup in the confined engine compartment. These temperatures may not be
harmful to the engine itself, but may degrade structures around the engine, such as composite engine mounts or installed
electrical components. Excess engine heat can also result in fuel vapor lock that prevents a subsequent restart.
Some installations have a propeller feathering system that reduces propeller drag during non-powered flight. If the pilot
can control the propeller blade pitch while in flight or after shutdown, the pilot should set the propeller as described in the
GFM/POH. For any inflight engine restart the pilot should follow the manufacturer's procedures.
Common Errors
Common errors during climb-out and shutdown procedures include:
• Failure to follow manufacturer’s recommended procedure for engine shutdown, feathering, and stowing (if
applicable).
• Failure to maintain positive aircraft control while performing engine shutdown procedures.
• Failure to follow proper engine extension and restart procedures.
Gliderport/Airport Traffic Patterns & Operations
Gliderports and airport operators within the United States should comply with Federal Aviation Administration (FAA)
recommended procedures established in Advisory Circulars (AC), the Aeronautical Information Manual (AIM), and
current FAA regulations. These publications serve as good references to help ensure safe glider operations.
Airport managers and glider operators usually establish traffic patterns for their operation to accommodate all the activities
that take place. Pilots planning to operate at a gliderport or airport should obtain a thorough briefing or checkout before
conducting flights at that facility. The landing surface serves as the primary reference to begin and fly each approach to
the landing area. Pilots commonly use an initial point (IP) as shown in Figure 7-31, which at the recommended altitude
will provide for sufficient gliding distance to reach the landing field with an adequate safety margin. The sequence of a
normal approach runs from over the IP to the downwind leg, base leg, final approach, flare, touchdown, rollout, and stop.
The IP may be located over the center of the gliderport/airport or at a remote location near the traffic pattern. Once past the
IP, pilots normally manage their energy to compensate for wind, traffic, terrain and obstacles. While a rectangular traffic
pattern is preferred, pilots may need to modify their traffic pattern since flying a pattern that results in a landing as intended
takes precedence over a rectangular pattern structure.
Touchdown point
Entry leg
Downwind leg
Final approach
Base leg
Initial point (IP)
Final approach
Base leg Downwind leg
Entry leg
Touchdown point
Initial point (IP)
45°
Factors that determine the turn point for the base leg:
Glide ratio, wind components, and airspeed.
Figure 7-31. Traffic pattern.
Pilot should understand the rationale for determining an IP. When approaching an unfamiliar landing area, a pilot may
not have a known IP. In this situation, the pilot should use the landing surface as the primary reference and set up a traffic
pattern that provides an equivalent margin of safety. Pilots should develop proper placement, altitude, and distances based
on wind, traffic, terrain, obstacles, and glider performance. In addition to environmental factors, the pilot should plan for
an approach and landing with other participating traffic in the pattern and know the right of way rules.
While glider pilots may compensate for winds and modify the traffic pattern to retain a safe approach angle, the pilot
normally plans to fly over the IP, where known, at an altitude of 800 to 1,000 feet AGL or as recommended by the local
field operating procedures. Once over the IP, the pilot flies along the downwind leg of the planned landing pattern. During
this time, the pilot should look for other aircraft and listen to the radio, if installed, for other aircraft in the vicinity of the
gliderport/airport. Glider pilots should plan to make any radio calls early in the pattern and then concentrate on the landing
task.
Pilots should complete the landing checklist prior to the downwind leg. A popular landing checklist mnemonic uses the
acronym FUSTALL.
• Flaps—set (if applicable)
• Undercarriage—down and locked (if applicable)
• Speed—normal approach speed established (as recommended by the GFM/POH)
• Trim—set
• Air brakes (spoilers/dive brakes)—checked for correct operation
• Landing area—look for wind, other aircraft, and personnel
• Land the glider
Normal Approach & Landing
Planning for an approach begins at some distance from the landing zone. Prior to the IP and downwind leg entry, the pilot
should consider the approach angle, distance from the landing area, spacing to accommodate other aircraft, and desired
approach airspeed. Pilots normally use the recommended approach speed in the GFM/POH, but they may use 1.5 V SO in
the absence of a recommended approach speed. The pilot should use spoilers/dive brakes as necessary to dissipate excess
altitude while maintaining the desired approach airspeed. During the entry into the traffic pattern, pilots should manage
trim and make coordinated turns limited to no more than 45° of bank, and the pilot should not conduct a 360° turn once
established on the downwind leg.
Downwind Leg
When approaching the IP, the pilot should maneuver the glider to enter the downwind leg. The lateral distance from a
downwind leg to the landing area should be such that the glider pilot can look down to the centerline of the landing area at a
30- to 45-degree angle. This sight picture equates to a lateral distance to the landing area of 800 to 1200 feet, which allows
the glider to fly inside any airplane traffic pattern and gives a better view of the landing area. The exact distance depends on
winds, other weather conditions, the type of glider, and the site topography. On a typical downwind leg, the glider should
descend to arrive abeam the touchdown point at an altitude between 500 and 600 feet AGL. The pilot may use the spoilers/
dive brakes to arrive at this altitude. The pilot should also monitor the glider’s position with reference to the touchdown
area. If the wind pushes the glider away from or toward the touchdown area, the pilot should establish a wind correction
angle, stop the drift, and plan to shorten or lengthen the downwind as needed. On the downwind leg, groundspeed increases
with any tailwind and shortens the elapsed time to reach the point at which to turn base.
Base Leg
The base leg normally starts with the touchdown point no more than 45° over the pilot’s shoulder looking back at the
touchdown area if under a no wind condition. However, pilots should adjust the downwind length based on the glide ratio
of the glider flown. Each glider pilot should evaluate the landing conditions, configure the glider for landing under those
conditions, and turn to base while keeping the point of intended touchdown within easy gliding range. Performing a slip or
extending drag devices can dissipate excess altitude, but nothing on a non- motorized glider will make up for insufficient
altitude.
Once established on the base leg, the pilot should scan for and detect any aircraft on long final approach. If using a radio,
the glider pilot can broadcast position for turn to final. The pilot should adjust the turn to correct for wind drift encountered
on the base leg and roll out on a heading that aligns with the landing area. The pilot should also adjust the spoilers/dive
brakes and/or slip as needed to position the glider at the desired approach angle. New pilots should learn to properly scan
for another aircraft operating in the traffic pattern. Pilots should also review the current revision of FAA Advisory Circular
(AC) 90-48, Pilots’ Role in Collision Avoidance.
Final Approach
The turn onto the final approach should not exceed a 45° bank and the pilot should use an appropriate approach angle
to start the final descent. The pilot normally makes a coordinated turn from base to final to line up with the centerline of
the touchdown area. The pilot should adjust the spoilers/dive brakes, as necessary, to fly the desired approach angle to a
specific spot on the ground and establish a stabilized approach at the recommended approach speed.
Stablized Approach
A stabilized approach requires the pilot to judge certain visual clues and then maintain a constant final descent airspeed,
approach angle, and configuration. Glider pilots should plan a downwind and base leg that allows them to turn from base to
final in position to continue on a stabilized approach. The final approach with spoilers/dive brakes extended approximately
half open (not necessarily half travel of the spoiler/dive brake control handle) creates an ideal approach for most gliders.
The pilot can devote significant attention toward outside visual cues to fine tune the approach. The pilot should not stare
at any one place, but rather scan from one point to another, such as from the aiming point to the horizon, to any objects
along the landing surface, to an area well short of the landing surface, and back to the aiming point. This makes it easier
to perceive any deviation from the desired glide path and determine if the glider is proceeding directly toward the aiming
point. The pilot should also glance at the airspeed indicator periodically and correct for any airspeed deviation.
A glider descending on stabilized final approach travels in a straight line towards a spot on the ground ahead, commonly
called the aiming point. If the glider maintains a constant glide path without a flare for landing, it will strike the ground at
the aiming point.
To the pilot, the aiming point appears to be stationary. It does not appear to move under the nose of the aircraft and does
not appear to move forward away from the aircraft. This feature identifies the aiming point—it does not move. However,
objects in front of and beyond the aiming point do appear to move as the distance is closed, and they appear to move
in opposite directions! For a constant angle glide path, the distance between the horizon and the aiming point remains
constant. If descending at a constant angle and the distance between the perceived aiming point and the horizon appears to
increase (aiming point moving down away from the horizon), then the true aiming point is farther down the runway. If the
distance between the perceived aiming point and the horizon decreases, meaning that the aiming point is moving up toward
the horizon, the true aiming point is closer than perceived.
When the glider is established on final approach, the landing surface normally appears as an elongated rectangle. When
viewed from the air during the approach, the phenomenon known as perspective causes the landing surface to assume the
shape of a trapezoid with the far end looking narrower than the approach end and the edge lines converging ahead. As a
glider continues down the glide path at a constant angle (stabilized), the image the pilot sees keeps the same shape, but
with proportionately larger dimensions. In other words, during a stabilized approach, the perceived shape of the landing
surface should not change. [Figure 7-32]
3° approach angle
1,600 feet from threshold
105 feet altitude
Same runway, same approach angle
800 feet from threshold
52 feet altitude
Same runway, same approach angle
400 feet from threshold
26 feet altitude
Figure 7-32. Runway shape during stabilized approach.
If the approach becomes shallow, the landing surface appears to shorten and becomes wider. Conversely, if the approach is
steepened, the landing surface appears to become longer and narrower. [Figure 7-33]
Too high Proper descent angle Too low
Figure 7-33. Change in runway shape if approach becomes narrow or steep.
During instruction and practice, a glider pilot acquires the skill to use visual cues to discern the true aiming point from any
distance out on final approach. From this, the pilot determines if the current glide path will result in either an undershoot
or overshoot. Note that since the pilot reduces the rate of descent during the flare, the actual touchdown occurs farther
down the field. Considering float during round out, a skilled pilot can predict the point of touchdown with some accuracy.
The round out, touchdown, and landing roll are much easier to accomplish when preceded by a stabilized final approach,
which reduces the chance of a landing mishap. Therefore, the pilot should detect and correct deviations from the desired
glide path early so that the magnitude of corrections is small. The pilot should make appropriate and smooth adjustments
in the spoilers/dive brakes to ensure proper glidepath control and should avoid pumping the spoilers/dive brakes from
full open to full close. If excess speed develops from a sudden dive at the end of the approach, the glider can float a
considerable distance that could preclude touching down in the desired landing area.
Round Out & Flare
When the glider approaches approximately 5 feet above the ground in a normal descent, the pilot begins a slow, smooth
transition from a normal approach attitude to a landing attitude, gradually rounding out the flightpath to one that is parallel
to and a few inches above the runway. The pilot gradually applies back-elevator pressure to slowly increase the pitch
attitude and AOA, which increases at a rate that allows the glider to continue settling slowly as forward speed decreases.
This is a continuous process until the glider touches down on the ground.
When the AOA is increased, the lift increases momentarily and gradually decreases the rate of descent and airspeed. During
the round out, the airspeed is decreased to touchdown speed while the lift is controlled so the glider settles gently onto the
landing surface. The round out is executed at a rate such that the proper landing attitude and the proper touchdown airspeed
are attained simultaneously just as the wheels contact the landing surface.
The rate at which the pilot executes the round out depends on the glider’s height above the ground, the rate of descent,
and the pitch attitude. A round out started excessively high needs to be executed more slowly than one started from a
lower height. When the glider appears to be descending very slowly, the increase in pitch attitude should be made at a
correspondingly slow rate.
Touchdown
The touchdown is the gentle settling of the glider onto the landing surface. During the round out, the airspeed decays such
that the glider touches down on the main gear. Drag devices in a glider such as spoilers or air brakes may also be used to
control the touchdown point if needed. As the glider settles, proper landing attitude is attained as necessary. The touchdown
should occur with the glider’s longitudinal axis parallel to the direction in which the glider is moving along the runway.
Failure to accomplish this imposes severe side loads on the landing gear. To avoid these side stresses, the pilot should not
allow the glider to touch down while turned into the wind or drifting. After touchdown full deployment of drag devices and
use of wheel brakes will increase the deceleration in the landing roll while maintaining directional control.
Pilots should avoid driving the glider into the ground using little or no flare. This type of landing puts excessive loads on
the landing gear and wings. Forcing the glider onto the ground at excessive speeds may introduce pilot induced oscillations,
such as porpoising. A good glider landing in most gliders with a main wheel and tailwheel (or skid) occurs on the main
wheel with the tail wheel just slightly touching or the tail wheel just barely off the surface. The main wheel can withstand
the shock of landings, but the tail wheel may not. Pilots should always follow the GFM/POH recommendations of the
manufacturer.
After Landing Roll
The landing process should never be considered complete until the glider has been brought to a complete stop. Accidents
may occur because of pilots abandoning their vigilance and failing to maintain positive control after getting the glider on
the ground. Loss of directional control may lead to an aggravated, uncontrolled, tight turn on the ground, or a ground loop.
The combination of centrifugal force acting on the center of gravity (CG) and ground friction of the main wheel resisting
it during the ground loop may cause the glider to tip or lean enough for the outside wingtip to contact the ground. Proper
directional control needs to be established early on after touchdown. The rudder serves the same purpose on the ground as
it does in the air—it controls the yawing of the glider. The effectiveness of the rudder is dependent on the airflow, which
depends on the speed of the glider.
The long, low wingtips of the glider are susceptible to damage from runway signage and runway lighting. When landing
on a runway or landing strip, the rollout should continue straight along the centerline of the touchdown area, and the pilot
should use full back stick on the elevator while keeping the glider wings level with aileron control. Pilots normally ensure
that a wing does not contact the ground until the glider reaches a low speed or stops. As control authority decays during the
ground roll, the pilot should apply brakes to avoid leaving the runway or landing area. However, if an obstacle becomes
a concern (possible in an off-airport landing or landing out), a coordinated turn on the ground may avoid the obstacle.
Turning off the runway should be done only when the pilot has the glider under control.
Landings in high, gusty winds or turbulent conditions occur using a higher approach airspeed to improve controllability,
provide a safe margin above stall airspeed, and allow better penetration into the headwind on final approach. As a rule of
thumb, pilots add one-half the reported gust factor (the difference between the sustained wind and reported gusts) to the
normal recommended approach airspeed.
Pilot Induced Pitch Oscillations During Landing
Over controlling the elevator during the landing flare can cause the glider to balloon well above the landing surface even
as airspeed decreases toward stalling speed. If the pilot pushes the stick forward after ballooning, the glider will rapidly
descend toward the ground. If the pilot pulls the control stick back to arrest the descent, the glider may balloon again or
experience a hard or nose-first landing depending on the airspeed. Wind gusts and turbulence increase the likelihood of
this type of PIO.
To prevent PIOs during the flare after ballooning, the pilot should stabilize the glider at an altitude of 3 to 4 feet and begin
the flare anew. If ballooning occurs at a low airspeed that takes the glider higher than a normal flare altitude, the pilot may
reduce the extension of the spoilers/dive brakes to moderate the descent rate.
The spoilers/dive brakes provide significant drag and reduced lift when fully deployed. A sudden extension while landing
results in a high sink rate and possible hard contact with the runway. This can lead to a rebound into the air and a series of
PIOs. If a wind gust or sudden retraction of the spoiler/dive brakes causes the glider to balloon, the pilot should adjust the
spoiler/dive brakes smoothly to reestablish an appropriate flare.
Forward Slip
A forward slip allows the pilot to steepen the approach path without increasing airspeed. While drag devices have reduced
the need for forward slips, pilots should know how to use them for short/off-field landings, and approaches over obstacles.
The forward slip retains the glider’s direction of motion although the nose of the glider points away from the direction of
travel. For a glider in straight flight, the pilot lowers the wing on the windward side using the ailerons. Simultaneously, the
pilot yaws the glider’s nose by applying opposite rudder to point the glider’s longitudinal axis at an angle to its original
flightpath. The correct amount of bank and yaw maintains the original ground track. The pilot should also raise the nose if
necessary, to prevent the airspeed from increasing.
Pilots should allow an extra margin of altitude for safety as part of an approach. If an arrival with excess altitude occurs
when nearing the boundary of the selected field, the pilot can dissipate the excess altitude using a forward slip.
The use of slips has definite limitations. Some pilots may try to lose altitude by erratic slipping rather than by smoothly
maneuvering, exercising good judgment, and using only a slight or moderate slip. In off-field landings, erratic or violent
slipping may lead to excess speed that could result in landing long or overshooting the entire field.
Sideslip
A sideslip, as distinguished from a forward slip, occurs with the glider’s longitudinal axis held parallel to the original
flightpath. While keeping the nose aligned using rudder control, the pilot lowers the wing on the upwind side of the glider
and adjusts the flightpath direction by varying the bank angle. [Figure 7-34]