should raise the nose; and when the airspeed is too low, lower the nose. If the pitch attitude is raised too high, the airplane settles rapidly
due to a slow airspeed and insufficient lift. For this reason, the pilot should never try to stretch a glide to reach the desired landing spot.
Note that certain single-engine turboprop airplanes experience an excessive rate of descent if the power is set to flight idle. In some cases,
if the powerplant failed, the manufacturer's checklist calls for feathering the propeller during a power-off glide. During flight training
in these airplanes, the propeller is not feathered as would be the case in an emergency or true power-off glide. During training and pilot
certification, where the manufacturer's checklist calls for propeller feathering in a power-off situation, the pilot should set sufficient
power to provide the performance that would be expected with the propeller feathered.
Uniform approach patterns, such as the 90° or 180° power-off approaches, are described further in this chapter. Practicing these approaches
provides a pilot with a basis on which to develop judgment in gliding distance and in planning an approach. While square patterns
demonstrate good planning, they are not required and may not be appropriate for every approach. For example, when conditions are not
as expected, pilots may need to dog-leg away from the runway on base or dog-leg toward the runway on base. Pilots may use S-turns,
slips, early or late extension of flaps, reduce airspeed below best glide, or increase airspeed slightly above best glide in a headwind in
order to stabilize the remaining approach, to reach the desired aiming point at an appropriate speed, and to touch down where planned.
Note that selection of the runway numbers as the touchdown point does not provide a safety cushion in case of a mechanical problem or
misjudgment. Selecting a point farther down the runway establishes an increased safety margin.
The basic procedure in these approaches involves closing the throttle at a given altitude and gliding to a key position. Starting with the
same energy (airspeed and height) each time the throttle is closed, makes the maneuver more predictable. The key position, like the
pattern itself, is not the primary objective; it is merely a convenient point in the air from which the pilot can judge what to do such that
the landing occurs at or just beyond the desired point. The selected key position should be one that is appropriate for the available altitude
and the wind condition. From the key position, the pilot should constantly evaluate the situation.
It should be emphasized that, although accurate spot touchdowns are important, safe and properly executed approaches and landings are
vital. A pilot should never sacrifice a good approach or landing just to land on the desired spot.
90° Power-Off Approach
The 90° power-off approach is made from a base leg and requires an approximate 90° turn onto the final approach. The approach path
may be varied by positioning the base leg closer to or farther out from the approach end of the runway according to wind conditions.
[Figure 9-25] The glide from the key position on the base leg through the 90° turn to the final approach is the final part of all accuracy
landing maneuvers. The 90° power-off approach usually begins from a rectangular pattern at approximately 1,000 feet above the ground
or at normal traffic pattern altitude. The airplane is flown on a downwind leg at the same distance from the landing surface as in a normal
traffic pattern. The before-landing checklist should be completed on the downwind leg, including extension of the landing gear if the
airplane is equipped with retractable gear.
Figure 9-25. Plan the base leg for wind conditions.
After a medium-banked turn onto the base leg is completed, the throttle is retarded slightly and the airspeed allowed to decrease to the
normal base-leg speed. [Figure 9-26] On the base leg, the airspeed, wind drift correction, and altitude are maintained while proceeding
to the 45° key position. At this position, the intended landing spot appears to be on a 45° angle from the airplane’s nose.
Figure 9-26. 90° power-off approach.
The pilot can determine the strength and direction of the wind from the amount of crab necessary to hold the desired ground track on the
base leg. This helps in planning the turn onto the final approach and provides some indication of when to lower the flaps.
At the 45° key position, the throttle is closed completely, the propeller control (if equipped) advanced to the full increase revolution
per minute (rpm) position, and altitude maintained until the airspeed decreases to the manufacturer’s recommended glide speed. In the
absence of a recommended speed, the pilot should use 1.4 VSO. When this airspeed is attained, the nose is lowered to maintain the gliding
speed and the controls trimmed. The wing flaps may be gradually lowered and the pitch attitude adjusted, as needed, to establish the
proper descent angle. The base-to-final turn is planned and accomplished so that upon rolling out of the turn, the airplane is aligned with
the runway centerline. If the approach is planned to be slightly high in the current configuration, the pilot will be assured of making the
aiming point. The wing flaps may be lowered, as needed, and the pitch attitude adjusted, as needed, to establish the proper descent angle
and airspeed (1.3 VSO), and the controls trimmed. Slight adjustments in pitch attitude and slips are used as necessary to control the glide
angle and airspeed. A crab or side slip can be used to maintain the desired flight path. A forward slip may be used momentarily to steepen
the descent without changing the airspeed. Full flaps should be delayed until it is clear that adding them will not cause the landing to be
short of the point. The pilot should never try to stretch the glide or retract the flaps to reach the desired landing spot.
On short final, full attention is given to making a good, safe landing rather than concentrating on the selected landing spot. The approach
angle used and final approach airspeed determine the probability of landing on the spot, and late adjustments to these parameters are not
appropriate. It is always better to execute a good landing away from the spot than to make a poor landing precisely on or just past the spot.
180° Power-Off Approach
The 180° power-off approach is executed by gliding with idle power from a given point on a downwind leg to a preselected landing
spot. [Figure 9-27] It is an extension of the principles involved in the 90° power-off approach just described. The objective is to further
develop judgment in estimating distances and glide ratios, in that the airplane is flown without power from a higher altitude and through
a 90° turn to reach the base-leg position at a proper altitude for executing the 90° approach.
Figure 9-27. 180° power-off approach.
The 180° power-off approach requires more planning and judgment than the 90° power-off approach. In the execution of 180° power-off
approaches, the airplane is flown on a downwind heading parallel to the landing runway. The altitude from which this type of approach
is started varies with the type of airplane, but should usually not exceed 1,000 feet above the ground, except with large airplanes. Greater
accuracy in judgment and maneuvering is required at higher altitudes.
When abreast of or opposite the desired landing spot, the throttle is closed and altitude maintained while decelerating to the manufacturer’s
recommended glide speed or 1.4 VSO. The point at which the throttle is closed is the downwind key position.
The turn from the downwind leg to the base leg is a uniform turn with a medium or slightly steeper bank. The degree of bank and amount
of this initial turn depend upon the glide angle of the airplane and the velocity and direction of the wind. Again, the base leg is positioned
as needed for the altitude or wind condition. Position the base leg to conserve or dissipate altitude so as to reach the desired landing spot.
The turn onto the base leg is made at an altitude high enough and close enough to permit the airplane to glide to what would normally be
the base key position in a 90° power-off approach. Initial flaps may be extended prior to the base key position if needed.
Although the base key position is important, it should not be overemphasized nor considered as a fixed point on the ground. Many
inexperienced pilots may gain a conception of it as a particular landmark, such as a tree, crossroad, or other visual reference, to be
reached at a certain altitude. This misconception leaves the pilot at a total loss any time such objects are not present. Both altitude and
geographical location should be varied as much as is practical to eliminate any such misconceptions. After reaching the base key position,
the approach and landing are the same as in the 90° power-off approach.
Common Errors
Common errors in the performance of power-off accuracy approaches are:
1. Downwind leg is too far from the runway/landing area.
2. Overextension of downwind leg resulting from a tailwind.
3. Inadequate compensation for wind drift on base leg.
4. Skidding turns in an effort to increase gliding distance.
5. Failure to lower landing gear in retractable gear airplanes.
6. Attempting to “stretch” the glide during an undershoot.
7. Premature flap extension/landing gear extension.
8. Use of throttle to increase the glide instead of merely clearing the engine.
9. Forcing the airplane onto the runway in order to avoid overshooting the designated landing spot.
Emergency Approaches and Landings (Simulated)
During dual training flights, the instructor should give simulated emergency landings by retarding the throttle and calling “simulated
emergency landing.” The objective of these simulated emergency landings is to develop a pilot’s accuracy, judgment, planning, procedures,
and confidence when little or no power is available. A simulated emergency landing may be given with the airplane in any configuration.
If the simulated power failure occurs while above best glide speed, the pilot allows the airplane to slow (or may even bleed off speed by
climbing) until reaching best glide speed. When reaching that speed, the nose can be lowered and the airplane trimmed to maintain that
speed. If the failure occurs at or below best glide speed, the nose should be lowered immediately to maintain or accelerate to best glide
speed. The pilot should ensure that the flaps and landing gear are in the proper configuration for the existing situation.
A constant gliding speed is usually maintained because variations of gliding speed nullify all attempts at accuracy in judgment of gliding
distance and the landing spot. The many variables, such as altitude, obstruction, wind direction, landing direction, landing surface and
gradient, and landing distance requirements of the airplane, determine the pattern and approach procedures to use.
The pilot may use any combination of normal gliding maneuvers, from wings level to spirals to eventually arrive at the normal key
position at a normal traffic pattern altitude for the selected landing area. From the key point on, the approach is a normal power-off
approach. [Figure 9-28]
Figure 9-28. Remain over intended landing area.
With the greater choice of fields afforded by higher altitudes, the inexperienced pilot may be inclined to delay making a decision, and
with considerable altitude in which to maneuver, errors in maneuvering and estimation of glide distance may develop.
All pilots should learn to determine the wind direction and estimate its speed from the windsock at the airport, smoke from factories or
houses, dust, brush fires, wind farms, or patterns displayed on nearby bodies of water .
Once a field has been selected, a pilot should indicate the proposed landing area to the instructor. Normally, the pilot should plan and fly
a pattern for landing on the field first elected until the instructor terminates the simulated emergency landing. This provides the instructor
an opportunity to explain and correct any errors; it also gives the pilot an opportunity to see the results of the errors. However, if the
pilot realizes during the approach that a poor field has been selected—one that would obviously result in disaster if a landing were to be
made—and there is a more advantageous field within gliding distance, a change to the better field should be permitted. The instructor
should thoroughly explain the hazards involved in these last-minute decisions, such as excessive maneuvering at very low altitudes.
Instructors should stress slipping the airplane, using flaps, varying the position of the base leg, and varying the turn onto final approach
as ways of correcting for misjudgment of altitude and glide angle.
Eagerness to get down is one of the most common faults of inexperienced pilots during simulated emergency landings. They forget about
speed and arrive at the edge of the field with too much speed to permit a safe landing. Too much speed is just as dangerous as too little;
it results in excessive floating and overshooting the desired landing spot. Instructors need to stress during their instruction that pilots
cannot dive at a field and expect to land on it.
During all simulated emergency landings, keep the engine warm and cleared. During a simulated emergency landing, either the instructor
or the pilot should have complete control of the throttle. There should be no doubt as to who has control since many near accidents have
occurred from such misunderstandings.
Every simulated emergency landing approach is terminated as soon as it can be determined whether or not a safe landing is assured. In
no case should it be continued to a point where it creates an undue hazard or an annoyance to persons or property on the ground.
In addition to flying the airplane from the point of simulated engine failure to where it is known that a reasonable safe landing could be
made (or to where it is known that the approach cannot be salvaged), a pilot should also receive instruction on certain emergency flight
deck procedures. The habit of performing these procedures should be developed to such an extent that, if an engine failure actually
occurs, a pilot checks the critical items that might get the engine operating again while selecting a field and planning an approach.
Combining the two operations—accomplishing emergency procedures and planning and flying the approach—is difficult during the
early training in emergency landings.
There are steps and procedures pilots should follow in a simulated emergency landing. Although they may differ somewhat from the
procedures used in an actual emergency, they should be learned thoroughly and each step called out to the instructor. The use of a
checklist is strongly recommended. Most airplane manufacturers provide a checklist of the appropriate items. [Figure 9-29]
Figure 9-29. Sample emergency checklist.
Critical items to be checked include the position of the fuel tank selector, the quantity of fuel in the tank selected, the fuel pressure gauge
to see if the electric fuel pump is needed, the position of the mixture control, the position of the magneto switch, and the use of carburetor
heat. Many actual emergency landings have been made and later found to be the result of the fuel selector valve being positioned to an
empty tank while the other tank had plenty of fuel. It may be wise to change the position of the fuel selector valve even though the fuel
gauge indicates fuel in all tanks because fuel gauges can be inaccurate. Many actual emergency landings could have been prevented if
the pilots had developed the habit of checking these critical items during flight training.
Instruction in emergency procedures is not limited to simulated emergency landings caused by power failures. Other emergencies
associated with the operation of the airplane should be explained, demonstrated, and practiced if practicable. Among these emergencies
are fire in flight, electrical or hydraulic system malfunctions, unexpected severe weather conditions, engine overheating, imminent fuel
exhaustion, and the emergency operation of airplane systems and equipment.
Faulty Approaches and Landings
Landing involves many precise, time-sensitive, and sequential control inputs. When corrected early, small errors are often not noticeable.
On the other hand, uncorrected errors may place the airplane and occupants in an undesirable state. Since pilot training normally includes
exposure to landing deviations and their appropriate remedies, this section covers several common landing imperfections.
Low Final Approach
When the base leg is too low, insufficient power is used, landing flaps are extended prematurely, or the velocity of the wind is misjudged,
the airplane may be well below the proper final approach path. In such a situation, the pilot would have to apply considerable power
to fly the airplane (at an excessively low altitude) up to the runway threshold. When it is realized the runway cannot be reached unless
appropriate action is taken, power should be applied immediately to maintain the airspeed while the pitch attitude is raised to increase
lift and stop the descent. When the proper approach path has been intercepted, the correct approach attitude is reestablished and the
power reduced and a stabilized approach maintained. [Figure 9-30] The pilot should not increase the pitch attitude without increasing
the power because the airplane decelerates rapidly and may approach the critical AOA and stall. In addition, the pilot should not retract
the flaps since this causes a sudden decrease in lift and causes the airplane to sink more rapidly. If there is any doubt about the approach
being safely completed, it is advisable to execute an immediate go-around.
Figure 9-30. Right and wrong methods of correction for low final approach.
High Final Approach
When the final approach is too high, the pilot may lower the flaps as required. Further reduction in power may be necessary, while
lowering the nose simultaneously to maintain approach airspeed and steepen the approach path. [ Figure 9-31] Alternatively, the pilot
could use a forward slip to increase the descent angle and rate of descent while maintaining proper approach speed. Since a sink rate
in excess of 800–1,000 feet per minute (fpm) is considered excessive, either technique avoids the high sink rates that would occur if
the pilot dives the airplane toward the aiming point. Since a high sink rate continued close to the surface makes it be difficult to slow
to a proper rate prior to ground contact, it is not a good idea to dive toward the aiming point. Therefore, when intercepting the proper
approach path from above, the pilot adjusts the power as required to maintain a stabilized approach. A go-around should be initiated if
the sink rate becomes excessive.
Figure 9-31. Change in glidepath and increase in descent rate for high final approach.
Slow Final Approach
On the final approach, when the airplane is flown at a slower than normal airspeed, the pilot’s judgment of the rate of sink (descent) and
the height of round out is difficult. During an excessively slow approach, the wing is operating near the critical AOA and, depending on
the pitch attitude changes and control usage, the airplane may stall or sink rapidly, contacting the ground with a hard impact.
Whenever a slow speed approach is noted, the pilot should apply power to accelerate the airplane and increase the lift to reduce the sink
rate and to prevent a stall. This is done while still at a high enough altitude to reestablish the correct approach airspeed and attitude. If
too slow and too low, it is best to execute a go-around.
Use of Power
Power can be used effectively during the approach and round out to compensate for errors in judgment. Power may be added to accelerate
the airplane, to increase lift without increasing the AOA, and to slow the descent to an acceptable rate. The increased propwash over the
wing behind the propeller(s) also provides an immediate boost in lift that also helps slow the descent rate. If the proper landing attitude is
attained and the airplane is only slightly high, the landing attitude is held constant and sufficient power applied to help ease the airplane
onto the ground. After the airplane has touched down, the pilot closes the throttle so the additional thrust and lift are removed and the
airplane remains on the ground.
High Round Out
Sometimes when the airplane appears to temporarily stop moving downward, the round out has been made too rapidly and the airplane
is flying level, too high above the runway. Continuing the round out further reduces the airspeed and increases the AOA to the critical
angle. This results in the airplane stalling and dropping hard onto the runway. To prevent this, the pitch attitude is held constant until
the airplane decelerates enough to again start descending. Then the round out is continued to establish the proper landing attitude. This
procedure is only used when there is adequate airspeed. It may be necessary to add a slight amount of power to keep the airspeed from
decreasing excessively and to avoid losing lift too rapidly.
When the proper landing attitude is attained, the airplane is approaching a stall because the airspeed is decreasing and the critical AOA
is being approached, even though the pitch attitude is no longer being increased. [Figure 9-32]
Figure 9-32. Rounding out too high.
Although back-elevator pressure may be relaxed slightly, the nose should not be lowered to make the airplane descend when fairly
close to the runway unless some power is added momentarily. The momentary decrease in lift that results from lowering the nose and
decreasing the AOA might cause the airplane to contact the ground with the nose-wheel first and may result in nose gear damage or
collapse.
It is recommended that a go-around be executed any time it appears the nose needs to be lowered significantly or that the landing is in
any other way uncertain.
Late or Rapid Round Out
Starting the round out too late or pulling the elevator control back too rapidly to prevent the airplane from touching down prematurely
can impose a significant load on the wings and cause an accelerated stall.
Suddenly increasing the AOA and stalling the airplane during a round out is a dangerous situation since it may cause the airplane to land
extremely hard on the main landing gear and then bounce back into the air. As the airplane contacts the ground, the tail is forced down
very rapidly by the back-elevator pressure and by inertia acting downward on the tail.