Weight-Shift Control Aircraft Flight

Normal (Calm Wind) Approaches and Landings (Part One)

Filed Under: WSC Approaches and Landings

A normal or regular approach and landing involves the use of procedures for what is considered a simple situation. It provides the minimum number of variables for the student pilot to learn during the first landings; that is, when engine power is at idle, wind is light, and the final approach is made directly into the wind, the final approach path has no obstacles, and the landing surface is firm and of ample length to bring the aircraft gradually to a stop. This includes normal runways used for WSC that are asphalt, concrete, solid dirt, gravel or short grass. The selected landing point should be beyond the runway’s approach threshold but within the first one-third portion of the runway.

The factors involved and the procedures described for the normal approach and landing also have applications to the other-than-normal approaches and landings which are discussed later in this chapter. Therefore, the principles of simple (or normal) operations are explained first and must be understood before proceeding to more complex operations. To assist the pilot in understanding the factors that influence judgment and procedures, the last part of the approach pattern and the actual landing is divided into five phases:

Base leg
Final approach
Roundout
Touchdown
After-landing roll

Remember that the manufacturer’s recommended procedures, including aircraft configuration, airspeeds, power, and other information relevant to approaches and landings in a specifi c make and model aircraft are contained in the Aircraft Flight Manual (AFM) and/or Pilot’s Operating Handbook (POH) for that aircraft. If any of the information in this chapter differs from the aircraft manufacturer’s recommendations as contained in the AFM/POH, the aircraft manufacturer’s recommendations take precedence.

Throttle Use

As discussed in Chapter 2, Aerodynamics, the WSC aircraft has a good glide ratio, and normal landings can easily be done with the power at idle. It is a good practice to master the landings with the throttle at idle so that the glide angle, speeds, and descent rates become habit and part of a normal routine. This is helpful so that, if there is an engine failure, the pilot is accustomed to landing with minimum power and is able to spot land the WSC aircraft for emergency conditions at or beyond a specified point. As a general practice for normal landings in calm conditions or a slight headwind, the throttle should be brought back to idle at the start of the base leg for landings.

Title 14 of the Code of Federal Regulations (14 CFR), section 91.119, Minimum Safe Altitudes: General, is an important safety precaution and states: “Except when necessary for takeoff or landing, no person may operate an aircraft anywhere below… an altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.” This allows long final approaches “with power when necessary,” but overall, it is important to be no lower than an altitude from which you can glide to a safe landing area. For the purposes of this approach-and-landing discussion, it is assumed that there are no safe landing areas other than the runway.

It should be noted that the power is above idle for some landing situations, such as:

Students first learning to land; a slower rate of descent is the result of higher power settings. In this case, the landings would be done with a target farther down the runway so a safe landing could always be made with engine failure.
Shallower descent angle if directed by air traffic control (ATC), or a longer final approach is required. •
High winds and/or turbulent conditions requiring a higher energy level.

For landings where throttle is required, the foot throttle is typically used so the hands can stay on the control bar while approaching the ground for this critical phase of flight. However, the hand/cruise throttle may be set above idle for specific situations as required by the pilot. Higher power settings for approaches and landings are discussed later in this chapter.

Base Leg

The placement of the base leg is one of the more important judgments made by the pilot in any landing approach. [Figure 11-1] The pilot must accurately judge the altitude and distance from which the descent results in landing at the desired point.

The base leg should be started at a point where the power can be brought back to idle and the WSC aircraft can glide to the landing spot at the approach speed recommended by the manufacturer. The intended landing point should not be at the end of the runway on a threshold or numbers, but beyond at the landing lines. [Figure 11-2]

Figure 11-2. Typical landing position on runway.

This provides some margin if the landing is shorter than anticipated. For smaller runways that do not have these markings, establish an appropriate landing point beyond the start of the runway, allowing plenty of room for the after-landing roll. At much larger airports, the landing can be done farther down the runway or at a location where the pilot can taxi off the runway and not delay other air traffic behind the aircraft.

After turning onto the base leg, the pilot should continue the descent with reduced power and approach airspeed as recommended by the manufacturer. As discussed in Chapter 7, Takeoff and Departure, this speed is at least 1.3 times the stall speed. Landing trim should be adjusted according to manufacturer specifications (if equipped).

Drift correction should be established and maintained to follow a ground track perpendicular to the extension of the centerline of the runway on which the landing is to be made. Since the final approach and landing are normally made into the wind, there may be a crosswind during the base leg. The aircraft must be angled sufficiently into the wind to prevent drifting farther away from the intended landing point.

The base leg should be continued to the point where a medium- to shallow-banked turn aligns the aircraft’s path directly with the centerline of the landing runway. This descending turn should be completed at a safe altitude that is dependent upon the height of the terrain and any obstructions along the ground track. The turn to the final approach should also be sufficiently above the airport elevation to permit a final approach long enough for the pilot to accurately estimate the resultant point of touchdown, while maintaining the proper approach airspeed. This requires careful planning for the starting point and radius of the turn. [Figure 11-3]

Figure 11-3. On base preparing to turn onto final.

Normally, it is recommended that the angle of bank not exceed a medium bank because the steeper the angle of bank, the higher the airspeed at which the aircraft stalls. Since the base-to-final turn is made at a relatively low altitude, it is important that a stall not occur at this point. If an extremely steep bank is needed to prevent overshooting the proper final approach path, it is advisable to discontinue the approach, go around, and plan to start the turn earlier on the next approach rather than risk a hazardous situation.

Final Approach

After the base-to-final approach turn is completed, the aircraft should be aligned directly in the extension of the centerline of the runway. The objective of a good final approach is to approach the runway with sufficient energy (manufacturer’s recommended airspeed) to land at or beyond some predetermined point. The landing area should provide sufficient runway behind for variations in approach conditions and runway ahead to allow either a full stop or a go-around if needed.

If there is a crosswind of any kind, the aircraft should be pointed into the wind slightly (see the Crosswind Approaches and Landings section). Focus should be to keep the ground track aligned with the centerline of the runway or landing surface, so that drift (if any) is recognized immediately. On a normal approach, with no crosswind drift, the longitudinal axis should be kept aligned with the runway centerline throughout the approach and landing.

After aligning the aircraft with the runway centerline, speed is adjusted as required for the desired rate of descent. Slight increases in power, if lower than expected, may be necessary to maintain the descent angle at the desired approach airspeed.

The descent angle should be controlled throughout the approach so that the aircraft lands in the center of the runway at the aiming point, as discussed earlier. The descent angle is affected by all four fundamental forces that act on an aircraft (lift, drag, thrust, and weight). If all the forces are constant, the descent angle is constant in calm air. The pilot can control these forces by adjusting the airspeed and power. The final approach sequence is shown in Figures 11-4 through 11-8.

Figure 11-4. Turning from base onto final.

Figure 11-5. Lining up on the runway centerline and maintaining position.

Figure 11-6. Coming to the runway and increasing speed slightly within 50 feet of the ground.

Figure 11-7. Maintaining speed and position over the middle of the runway.

Figure 11-8. Starting the roundout by increasing angle of attack (AOA) slightly at about 10 to 15 feet above the runway.

In a descent for final approach, if the WSC is slowed with an angle of attack that is too high and without an increase of power, the aircraft settles very rapidly and touches down short of the desired area. For this reason, the pilot should never try to stretch a glide by applying forward control bar pressure alone to reach the desired landing area. Because this brings the speed below the minimum drag speed, the gliding distance decreases if power is not added simultaneously.

Additionally, this is a lower energy approach and may be slower than the manufacturer’s safe approach speed. The proper angle of descent to the runway must be maintained at the minimum speed recommended by the manufacturer, with a flatter descent angle obtained with increases in power as required. Steeper descent angles are obtained with headwinds or the pilot increasing speed/decreasing the angle of attack, both of which are covered later in this chapter.

Normal (Calm Wind) Approaches and Landings (Part Two)

Filed Under: WSC Approaches and Landings

Estimating Height and Movement

During the final approach, roundout, and touchdown, vision is of prime importance. To provide a wide scope of vision and to foster good judgment of height and movement, the pilot’s head should assume a natural, straight-ahead position. The pilot’s visual focus should not be fixed on any one side or any one spot ahead of the aircraft. The pilot should maintain a deliberate awareness of the runway centerline (if available) or distance from either side of the runway within his or her peripheral field of vision.

Accurate estimation of distance is, besides being a matter of practice, dependent upon how clearly objects are seen; vision must be focused properly so that important objects stand out as clearly as possible. Speed blurs objects at close range. For example, one can note this effect in an automobile moving at high speed. Nearby objects seem to merge together in a blur, while objects farther away stand out clearly. The driver subconsciously focuses the eyes sufficiently far ahead of the automobile to see objects distinctly.

The distance at which the pilot’s vision is focused should be proportionate to the speed at which the aircraft is traveling over the ground. Thus, as speed is reduced during the roundout, the focus distance ahead of the aircraft should be decreased accordingly.

If the pilot attempts to focus on a reference that is too close or looks directly down, the reference is blurred, and the reaction is either too abrupt or too late. In this case, the pilot’s tendency is to overcontrol, round out high, and make a stalled, drop-in landing. When the pilot focuses too far ahead, accuracy in judging the closeness of the ground is lost and the consequent reaction is too slow since there is no apparent necessity for action. This results in the aircraft flying into the ground nose first without a proper roundout.

The best way to recognize and become accustomed to heights and speeds for a particular WSC aircraft is to perform low passes over the runway, as discussed earlier, with energy management. Perform a normal approach first, then a high-energy pass at a higher speed, and then medium-energy passes at lower speeds. These exercises are performed first in calm winds at a height, as an example, at which the wheels are 10 feet above the runway, then lowering to just inches above the runway as the pilot’s skills build. The objective is to become proficient at flying straight down the runway centerline at a constant altitude. This exercise provides the opportunity to determine height and speed over the runway before any landings are performed. These should generally be performed in mild conditions. Higher energy and greater heights above the runway are required in windier and bumpier conditions.

Roundout (Flare)

The roundout is a slow, smooth transition from a normal approach speed to a landing attitude, gradually rounding out the flightpath to one that is parallel with, and within a very few inches above, the runway. When the aircraft, in a normal descent, approaches within what appears to be 10 to 15 feet above the ground, the roundout or fl are should be started and be a continuous process slowing until the aircraft touches down on the ground.

It should be noted that the terms “roundout” and “flare” are defined and used interchangeably throughout the aviation industry for slowing the aircraft during final approach and touching down. The term “roundout” is used in this handbook since it provides a better description for the WSC landing process and WSC students are more successful learning landings using the term roundout instead of fl are.

As the aircraft reaches a height where the back wheels are one to two inches above the ground, the roundout is continued by gradually pushing the control bar forward as required to maintain one to two inches above the runway as the WSC aircraft slows. [Figure 11-9]

Figure 11-9. Changing angle of attack during roundout by slowly and continuously pushing forward on the control bar until touchdown.

This causes the aircraft’s nosewheel to gradually rise to the desired landing attitude. The AOA should be increased at a rate that allows the aircraft to continue flying just above the runway as forward speed decreases until the control bar is full forward and the back wheels settle onto the runway.

During the roundout, the airspeed is decreased to touchdown speed while the lift is controlled so the aircraft settles gently onto the landing surface. The roundout should be executed at a rate at which 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 roundout is executed depends on the aircraft’s height above the ground, the rate of descent, and the airspeed. A roundout started excessively high must be executed more slowly than one from a lower height to allow the aircraft to descend to the ground while the proper landing attitude is being established. The rate of rounding out must also be proportionate to the rate of closure with the ground. When the aircraft appears to be descending very slowly, the increase in pitch attitude (slowing of the WSC) must be made at a correspondingly low rate.

Visual cues are important in roundout at the proper altitude and maintaining the wheels a few inches above the runway until eventual touchdown. Roundout cues are dependent primarily on the angle at which the pilot’s central vision intersects the ground (or runway) ahead and slightly to the side. Proper depth perception is a factor in a successful roundout, but the visual cues used most are those related to changes in runway or terrain perspective and to changes in the size of familiar objects near the landing area such as fences, bushes, trees, hangars, and even sod or runway texture. The pilot should direct central vision at a shallow downward angle of 10° to 15° toward the runway as the roundout is initiated. [Figure 11-10]

Figure 11-10. To obtain necessary visual cues, the pilot should look toward the runway at a shallow angle.

Maintaining the same viewing angle causes the point of visual interception with the runway to move progressively rearward toward the pilot as the aircraft loses altitude. This is an important visual cue in assessing the rate of altitude loss.

Conversely, forward movement of the visual interception point indicates an increase in altitude and would mean that the pitch angle was increased too rapidly resulting in an over roundout. The following are also used to judge when the wheels are just a few inches above the runway: location of the visual interception point in conjunction with assessment of flow velocity of nearby off-runway terrain, and the similarity in appearance of height above the runway ahead of the aircraft to the way it looked when the aircraft was taxied prior to takeoff.

A common error during the roundout is rounding out too much and too fast. This error can easily be avoided by gradually increasing the AOA with a controlled descent until the wheels are one inch above the surface and never climbing during a roundout with a gradual and controlled roundout.

Touchdown

After a controlled roundout, the touchdown is the gentle settling of the aircraft onto the landing surface. For calm air conditions, the roundout can be made with the engine idling, and touchdown can be made at minimum controllable airspeed so that the aircraft touches down on the main gear at the approximate stalling speed. As the aircraft settles, the proper landing attitude is attained by application of whatever control bar forward pressure is necessary. In calm wind conditions, the goal is to round out smoothly and have the control bar touch the front tube as the back wheels touch the ground. [Figures 11-11 through 11-14] Once the rear wheel settles to the surface, the nosewheel settles to the ground. The control bar should be pulled all the way back to eliminate the possibility of lifting off the ground because of a wind gust. Pulling the nose down completely can also be used for aerodynamic braking if needed.

Figure 11-11. Maintaining speed from final approach in the center of the runway at about 20 feet above the runway.

Figure 11-12. Starting the roundout at about 10 to 15 feet above the runway surface.

Figure 11-13. Continuing the roundout as speed bleeds off and the WSC back wheels are inches above the runway.

Figure 11-14. Completing the roundout with the control bar full forward and the back wheels settling to the runway.

After-Landing Roll

The landing process must never be considered complete until the aircraft decelerates to normal taxi speed during the landing roll or has been brought to a complete stop when clear of the landing area. Many accidents have occurred as a result of pilots abandoning their vigilance and positive control after getting the aircraft on the ground.

The pilot must make only slight turns to maintain direction until the WSC has slowed to taxiing speed. An abrupt turn at high speed could possibly lift a rear wheel, roll the WSC over, or force the wingtip to the ground. The WSC must slow to taxing speed before any sharp turn can be made to exit the runway.

The brakes of an aircraft serve the same primary purpose as the brakes of an automobile—to reduce speed on the ground. Maximum brake effectiveness is just short of the skid point. If the brakes are applied so hard that skidding takes place, braking becomes ineffective. Skidding can be stopped by releasing the brake pressure. Also, braking effectiveness is not enhanced by alternately applying and reapplying brake pressure. The brakes should be applied firmly and smoothly as necessary.

WSC aircraft have nosewheel or rear wheel braking systems. For nosewheel systems, if braking is required right away, the nose should be lowered so the nosewheel touches the ground and the brakes can be applied. The nose should be lowered for any aerodynamic braking at the higher speeds.

Lowering the nose also provides greater force on the front wheel for superior braking effectiveness. Any skidding of the front wheel with braking causes the loss of directional control of the WSC aircraft and the skidding must be stopped by letting up on the brake. Skidding can be the greatest problem operating on slick surfaces such as wet grass. Rear wheel braking systems are heavier and more complex, but provide better braking force because there are two wheels instead of one and there is more weight on the rear wheels. Braking effectiveness should be evaluated by the pilot for each type of runway being used. If the available runway permits, the speed of the aircraft should be allowed to dissipate in a normal manner with minimum use of brakes. [Figure 11-15]

Figure 11-15. WSC aircraft follows the taxi line to exit the runway while slowing the aircraft and maintaining control of the wing.

The control bar serves the same purpose on the ground as in the air—it changes the lift and drag components of the wings. During the after-landing roll, the control bar should be used to keep the wings level in much the same way it is used in flight. If a wing starts to rise, roll control should be applied to lower it. Procedures for crosswind conditions are explained further in the Crosswind Approach and Landing section of this chapter.

Airport Operations and Standard Airport Traffic Patterns (Part Two)

Filed Under: WSC Airport Traffic Patterns

Standard Airport Traffic Patterns

A segmented circle in Figure 10-7 provides traffic patterns so there is no air traffic over the lower right hand area, which could be a hazard or populated area.

Figure 10-7. An airport with two runways and a hazard, noise sensitive, or populated area to the lower right where the segmented circle specifies traffic not to fly over this area.

Inbound to an uncontrolled airport, the CTAF frequency should be monitored to listen for other aircraft in the pattern to find out what is the active runway being used by other air traffic. [Figure 10-8]

Figure 10-8. Approaching a busy airport with multiple runways and listening to the Common Traffic Advisory Frequency (CTAF) for the pattern being used because of the wind conditions.

When approaching an airport for landing, the traffic pattern should be entered at a 45° angle to the downwind leg, headed toward a point abeam of the midpoint of the runway to be used for landing as shown in Figures 10-1 and 10-7.

Figure 10-1. Left and right hand traffic patterns. The WSC pattern altitude shown is the same as the airplane but the slower WSC aircraft uses a smaller “inside pattern” or “tight pattern.” — Figure 10-1. Left and right hand traffic patterns. The WSC pattern altitude shown is the same as the airplane but the slower WSC aircraft
uses a smaller “inside pattern” or “tight pattern.”

Arriving aircraft should be at the proper traffic pattern altitude before entering the pattern and should stay clear of the traffic flow until established on the entry leg. Entries into traffic patterns while descending create specific collision hazards and should always be avoided. During the WSC 45° entry into the pattern, the WSC aircraft must pass through the larger airplane pattern, so it is essential that alert see-and-avoid procedures plus additional radio communications be practiced during this transition.

The entry leg should be of sufficient length to provide a clear view of the entire traffic pattern and to allow the pilot adequate time for planning the intended path in the pattern and the landing approach.

The downwind leg is a course flown parallel to the landing runway but in a direction opposite to the intended landing direction. This leg for the slower WSC aircraft should be approximately ¼ to ½ mile out from the landing runway, and at the specified traffic pattern altitude unless the airport specifically specifies a lower altitude for WSC aircraft. [Figure 10-9]

Figure 10-9. After hearing other aircraft using the normal pattern as described in the Airport/Facility Directory (A/FD), pilot descended and entered the downwind leg (landing runway highlighted in red) midfield within gliding distance of the runway in case of an engine failure.

The faster airplanes would be ½ to 1 mile out from the landing runway. During this leg, the before landing check should be completed. Pattern altitude should be maintained until abeam the approach end of the landing runway. At this point, power should be reduced and a descent begun. The downwind leg continues past a point abeam the approach end of the runway to a point approximately 45° from the approach end of the runway, and a medium bank turn is made onto the base leg.

The base leg is the transitional part of the traffic pattern between the downwind leg and the final approach leg. Depending on the wind condition, it is established at a sufficient distance from the approach end of the landing runway to permit a gradual descent to the intended touchdown point. The ground track of the aircraft while on the base leg should be perpendicular to the extended centerline of the landing runway, although the longitudinal axis of the aircraft may not be aligned with the ground track when it is necessary to turn into the wind to counteract drift. While on the base leg and before turning onto the final approach, the pilot must ensure that there is no danger of colliding with another aircraft that may be on the final approach. This is especially important since the WSC aircraft is in a tighter pattern and could be flying onto the final approach of faster airplanes.

The final approach leg is a descending flightpath starting from the completion of the base-to-final turn and extending to the point of touchdown. This is probably the most important leg of the entire pattern because the pilot’s judgment and procedures must be the sharpest to control the airspeed and descent angle accurately while approaching the intended touchdown point.

As stipulated in 14 CFR part 91, aircraft while on final approach to land or while landing have the right-of-way over other aircraft in flight or operating on the surface. When two or more aircraft are approaching an airport for the purpose of landing, the aircraft at the lower altitude has the right of way. A pilot should not take advantage of this rule to cut in front of or overtake another aircraft on final approach.

The departure leg of the rectangular pattern is a straight course aligned with, and leading from, the takeoff runway. This leg begins at the point the aircraft leaves the ground and continues until the 90° turn onto the crosswind leg is started. On the departure leg after takeoff, the pilot should continue climbing straight ahead, and, if remaining in the traffic pattern, commence a turn to the crosswind leg beyond the departure end of the runway within 300 feet of pattern altitude. If departing the traffic pattern, continue straight out or exit with a 45° turn (to the left when in a left-hand traffic pattern; to the right when in a right-hand traffic pattern) beyond the departure end of the runway after reaching pattern altitude.

An upwind leg is a course flown parallel to the landing runway, but in the same direction as the intended landing direction. The upwind leg continues past a point abeam the departure end of the runway to where a medium bank 90° turn is made onto the crosswind leg. The upwind leg is also the transitional part of the traffic pattern when on the final approach and a go-around is initiated and climb attitude is established. When a safe altitude is attained, the pilot should commence a shallow bank turn to the right side of the runway. This allows better visibility of the runway for departing aircraft. [Figure 10-10]

The crosswind leg is the part of the rectangular pattern that is horizontally perpendicular to the extended centerline of the takeoff runway and is entered by making approximately a 90° turn from the departure or upwind leg. On the crosswind leg, the aircraft proceeds to the downwind leg position.

In most cases, the takeoff is made into the wind in which case it is now approximately perpendicular to the aircraft’s flightpath. As a result, the aircraft has to be turned or headed slightly into the wind while on the crosswind leg to maintain a ground track that is perpendicular to the runway centerline extension.

Chapter Summary

Airport patterns provide organized air traffic flows into and out of an airport. An airport traffic pattern is established appropriate to the local conditions, including the direction and placement of the pattern, altitude to be fl own, and procedures for entering and leaving the pattern.

The legs of an airport pattern from takeoff are:

Departure—direction of takeoff on the centerline of the runway
Crosswind—first 90° turn flying perpendicular to the takeoff direction
Downwind—second 90° turn flying parallel to the takeoff direction opposite the direction of takeoff and landing
Base—third 90° turn flying perpendicular towards the runway centerline
Final—forth 90° turn headed down the centerline of the runway to land

Pilots must research and determine from preflight preparation the possible runways and patterns for runways at the intended airports for the flight. The pilot must determine the actual pattern at the airport from observation and talking with other pilots on the CTAF or from the wind direction if no other pilots are in the pattern. Normal airport patterns are always left hand unless indicated otherwise.

Additional information on airport operations can be found in the Pilot’s Handbook of Aeronautical Knowledge, the Aeronautical Information Manual (AIM), Chapter 2, Aeronautical Lighting and Other Airport Visual Aids, Chapter 4, Air Traffic Control, and Chapter 5, Air Traffic Procedures; and 14 CFR part 91, Subpart B, Flight Rules, Subpart C, Equipment, Instrument and Certificate Requirements, and Subpart D, Special Flight Operations.

Airport Operations and Standard Airport Traffic Patterns (Part One)

Filed Under: WSC Airport Traffic Patterns

Airport Operations

Airports vary in complexity from small grass or sod strips to major terminals having multiple paved runways and taxiways. Regardless of the type of airport, the pilot must know and abide by the rules and general operating procedures applicable to the airport being used. These rules and procedures are based not only on logic or common sense but also on courtesy, and their objective is to keep air traffic moving with maximum safety and efficiency. The use of any traffic pattern, service, or procedure does not alter the responsibility of pilots to see and avoid other aircraft.

Generally, there are two types of airport operations:

Uncontrolled airports where there is no control tower
Controlled airports where there is a control tower with an air traffic controller

Airport operations is a prerequisite for reading and understanding this chapter. The Pilot’s Handbook of Aeronautical Knowledge (FAA-H-8083-25) chapter on airport operations is the starting point for this subject. Additionally, the portions of the Aeronautical Information Manual (AIM) covering aeronautical lighting and other airport visual aids, airspace, and air traffic control, should be studied prior to reading this chapter.

The following airport patterns are applicable to both towered and nontowered airport operations; however, in nontowered airports the pilot should use the information presented in this chapter along with the references provided in the summary to coordinate with the other air traffic. When flying at towered airports, the principles must be understood to understand the air traffic controller’s instructions. The pilot is always responsible for “see and avoid” and must continually look for other aircraft in towered and nontowered operations.

Standard Airport Traffic Patterns

To assure that air traffic flows into and out of an airport in an orderly manner, an airport traffic pattern is established appropriate to the local conditions, including the direction and placement of the pattern, altitude to be flown, and procedures for entering and leaving the pattern. Unless the airport displays approved visual markings indicating that turns should be made to the right, pilots should make all turns in the pattern to the left.

When operating at an airport with an operating control tower, the pilot receives by radio a clearance to approach or depart, as well as pertinent information about the traffic pattern. If there is not a control tower, it is the pilot’s responsibility to determine the direction of the traffic pattern, to comply with the appropriate traffic rules, and to display common courtesy toward other pilots operating in the area.

The pilot is not expected to have extensive knowledge of all traffic patterns at all airports; but if the pilot is familiar with the basic rectangular pattern, it is easy to make proper approaches and departures from most airports, regardless of whether they have control towers. At airports with operating control towers, the tower operator may instruct pilots to enter the traffic pattern at any point or to make a straight-in approach without flying the usual rectangular pattern. Many other deviations are possible if the tower operator and the pilot work together in an effort to keep traffic moving smoothly. Jets or heavy aircraft frequently fly wider and/or higher patterns than lighter aircraft and in many cases make a straight-in approach for landing.

The standard rectangular traffic pattern and terms are illustrated in Figure 10-1. The terms of an airport in the pattern after takeoff are described in Figure 10-1.

Departure leg—the flightpath which begins after takeoff and continues straight ahead along the extended runway centerline.

Crosswind leg—a flightpath at right angles to the landing runway off its takeoff end.

Downwind leg—a flightpath parallel to the landing runway in the opposite direction of landing.

Base leg—a flightpath at right angles to the landing runway off its approach end and extending from the downwind leg to the intersection of the extended runway centerline (third left hand 90° turn).

Final approach—a flightpath in the direction of landing along the extended runway centerline from the base leg to the runway.

Upwind leg—a flightpath parallel to the landing runway in the direction of landing (not shown in Figure 10-1).

The traffic pattern altitude is usually 1,000 feet above the elevation of the airport surface; however, many airports use different pattern altitudes for different types of aircraft. This information can be found in the Airport/Facility Directory (A/FD). The use of a common or known altitude at a given airport is a key factor in minimizing the risk of collisions at airports without operating control towers because aircraft can be expected to be at a certain level making it easier to see.

Compliance with the basic rectangular traffic pattern reduces the possibility of conflicts at airports without an operating control tower. It is imperative that the pilot form the habit of exercising constant vigilance in the vicinity of airports even though the air traffic appears to be light. The objective is to have both the fast and the slower weight-shift control (WSC) aircraft completing the pattern at the same interval.

The slower the aircraft is, the tighter the pattern is, as shown in Figure 10-1. The terminology is a “tight pattern” or “inside pattern” for the slower WSC aircraft in operations with faster aircraft. Using Figure 10-1 as an example, if the airplane is flying the pattern at 80 knots and the WSC aircraft is flying an inside pattern at 40 knots (that is half the distance), then the WSC aircraft and the airplane will fly around the pattern with the same interval.

The WSC pilot must determine the size of the pattern to create the same interval. This is commonplace at nontowered airports where WSC aircraft operate with faster aircraft. Both aircraft are going around the pattern at the same time with the slower WSC aircraft flying a tighter pattern and the faster airplane flying the larger pattern. In Figure 10-2, the WSC aircraft is establishing an inside airport pattern turning from crosswind to downwind.

Figure 10-2. After takeoff and departure, turning from the crosswind to the downwind leg while climbing to pattern altitude.

In Figure 10-3, the aircraft shown is in the middle of the downwind leg flying an inside pattern.

Figure 10-3. Weight-shift control on the downwind leg of an airport inside pattern.

When entering the traffic pattern at an airport without an operating control tower, inbound pilots are expected to listen to the other aircraft on the CTAF (Common Traffic Advisory Frequency), observe other aircraft already in the pattern, and conform to the traffic pattern in use. If other aircraft are not in the pattern, then traffic indicators on the ground and wind indicators must be checked to determine which runway and traffic pattern direction should be used. [Figure 10-4 and 10-5]

Figure 10-4. Left hand pattern for runway in both directions.

Figure 10-5. Left hand pattern for one direction and right hand pattern for other direction.

Many airports have L-shaped traffic pattern indicators displayed with a segmented circle adjacent to the runway. The short member of the L shows the direction in which traffic pattern turns should be made when using the runway parallel to the long member. These indicators should be checked while at a distance away from any pattern that might be in use, or while at a safe height above pattern altitudes. When the proper traffic pattern direction has been determined, the pilot should then proceed to a point clear of the pattern before descending to the pattern altitude.

As discussed earlier, all patterns are left hand unless indicated otherwise. Sectional aeronautical charts list a right hand pattern along with the airport information as shown in Figure 10-6. The segmented circle of Figure 10-5 and the airport shown in Figure 10-6 both clearly show the patterns for this airport.

Figure 10-6. Example of traffic pattern indicator on sectional showing right hand pattern for runway 9. See Figure 10-5 for segmented circle for this airport.

S-Turns Across a Road and Turns Around a Point

Filed Under: WSC Ground Reference Maneuvers

S-Turns Across a Road

An S-turn across a road is a practice maneuver in which the aircraft’s ground track describes semicircles of equal radii on each side of a selected straight line on the ground. Reference Figure 9-6 throughout this S-turn across the road section.

The straight line may be a road, fence, railroad, or section line that lies perpendicular to the wind and should be of sufficient length for making a series of turns. A constant altitude should be maintained throughout the maneuver.

S-turns across a road present one of the most elementary problems in the practical application of the turn and in the correction for wind drift in turns. While the application of this maneuver is considerably less advanced in some respects than the rectangular course, it is taught after the student has been introduced to that maneuver in order that the student may have a knowledge of the correction for wind drift in straight flight along a reference line before the student attempts to correct for drift by playing a turn.

The objectives of S-turns across a road are to develop the ability to compensate for drift during turns, orient the flightpath with ground references, follow an assigned ground track, arrive at specified points on assigned headings, and divide the pilot’s attention. The maneuver consists of crossing the road at a 90° angle and immediately beginning a series of 180° turns of uniform radius in opposite directions, re-crossing the road at a 90° angle just as each 180° turn is completed. The maneuver can be started with either a left hand turn or a right hand turn to go in either direction. Figure 9-6 starts the turn in a left hand turn as an example.

Accomplishing a constant radius ground track requires a changing roll rate and angle of bank to establish the wind correction angle. Both increase or decrease as the groundspeed increases or decreases.

The bank must be steepest when beginning the turn on the downwind side of the road and must be shallowed gradually as the turn progresses from a downwind heading to an upwind heading. On the upwind side, the turn should be started with a relatively shallow bank and then gradually steepened as the aircraft turns from an upwind heading to a downwind heading. In this maneuver, the aircraft should be rolled from one bank directly into the opposite just as the 90° reference line on the ground is crossed.

Before starting the maneuver, a straight ground reference line or road that lies 90° to the direction of the wind should be selected, then the area checked to ensure that no obstructions or other aircraft are in the immediate vicinity. The road should be approached from the upwind side at the selected altitude on a downwind heading. When directly over the road, the first turn should be started immediately. [Figure 9-6, position 1 and Figure 9-7]

Figure 9-7. Pilot’s view of crossing a reference line (road) at 90° wings level starting the S-turn maneuver.

With the aircraft headed downwind, the groundspeed is greatest and the rate of departure from the road is rapid; the roll into the steep bank must be fairly rapid to attain the proper wind correction angle. [Figure 9-6, position 2] This prevents the aircraft from flying too far from the road and from establishing a ground track of excessive radius.

During the latter portion of the first 90° turn, when the aircraft’s heading is changing from a downwind heading to a crosswind heading, the groundspeed becomes less and the rate of departure from the road decreases. [Figure 9-6, position 2 to 3, and Figure 9-8] The wind correction angle is at the maximum when the aircraft is headed directly crosswind. [Figure 9-6, position 3]

Figure 9-8. Pilot’s view in starting semicircle turning left from downwind to crosswind.

After turning 90°, the aircraft’s heading becomes more and more an upwind heading, the groundspeed decreases, and the rate of closure with the road becomes slower. If a constant steep bank were maintained, the aircraft would turn too quickly for the slower rate of closure and would prematurely be headed perpendicular to the road. Because of the decreasing groundspeed and rate of closure while approaching the upwind heading, it is necessary to gradually shallow the bank during the remaining 90° of the semicircle, so that the wind correction angle is removed completely [Figure 9-9] and the wings become level as the 180° turn is completed at the moment the road is reached. [Figure 9-6, position 4]

Figure 9-9. Student completing semicircle, preparing to level out to cross perpendicular to the road.

At the instant the road is being crossed at 90° to it, a turn in the opposite direction should be started. Since the aircraft is still flying into the headwind, the groundspeed is relatively low. Therefore, the turn must be started with a shallow bank to avoid an excessive rate of turn that would establish the maximum wind correction angle too soon. The degree of bank should be that which is necessary to attain the proper wind correction angle so the ground track describes an arc the same size as the one established on the downwind side.

Since the aircraft is turning from an upwind to a downwind heading, the groundspeed increases and after turning 90° the rate of closure with the road increases rapidly. [Figure 9-6, position 5]

Consequently, the angle of bank and rate of turn must be progressively increased so that the aircraft has turned 180° at the time it reaches the road. Again, the rollout must be timed so the aircraft is in straight-and-level flight directly over and perpendicular to the road. [Figure 9-6, position 6]

Throughout the maneuver a constant altitude and airspeed should be maintained, and the bank should be changing constantly to effect a true semicircular ground track. Common errors in the performance of S-turns across a road are:

Failure to adequately clear the area.
Creating too small of a radius/too high of a banked turn during the start of the maneuver.
Creating banked turns too high to complete the maneuver.
Poor coordination creating variations in airspeeds.
Gaining or losing altitude.
Inability to visualize the half circle ground track.
Poor timing in beginning and recovering from turns.
Faulty correction for drift.
Inadequate visual lookout for other aircraft.
Inability to judge closure rates to the road and adjust the bank angle so the semi-circle is completed at 90° to the reference road.

Turns Around a Point

Turns around a point, as a training maneuver, is a logical extension of the principles involved in the performance of S-turns across a road. The objectives are to:

Further perfect turning technique.
Perfect the ability to control the aircraft subconsciously while dividing attention between the flightpath and ground references.
Teach the student that the radius of a turn is a distance that is affected by the degree of bank used when turning with relation to a definite object.
Develop a keen perception of altitude.
Perfect the ability to correct for wind drift while in turns.

In turns around a point, the aircraft is flown in two or more complete circles of uniform radii or distance from a prominent ground reference point using a maximum bank of approximately 45° while maintaining a constant altitude.

The factors and principles of drift correction that are involved in S-turns are also applicable in this maneuver. As in other ground track maneuvers, a constant radius around a point requires a constantly changing angle of bank and angles of wind correction if any wind exists. The closer the aircraft is to a direct downwind heading where the groundspeed is greatest, the steeper the bank and the faster the rate of turn required to establish the proper wind correction angle. The more nearly it is to a direct upwind heading where the groundspeed is least, the shallower the bank and the slower the rate of turn required to establish the proper wind correction angle. Throughout the maneuver, the bank and rate of turn must be varied gradually in proportion to the groundspeed.

The point selected for turns around a point should be prominent, easily distinguished by the pilot, and yet small enough to present precise reference. [Figures 9-10 through 9-12]

Figure 9-11. Downwind portion of turn about a point, which is the gazebo jutting out into the lake. Notice the wing is low on the downwind portion where the angle of bank is greatest.

Figure 9-12. Upwind portion of the turn about a point. Notice the wing is higher because bank angle is not at as steep during the upwind portion headed into the wind to maintain a constant radius circle.

Isolated trees, crossroads, or other similar small landmarks are usually suitable. Right and left hand turns about a point should be practiced to develop technique in both directions. The example used here is right hand turns.

To enter turns around a point, the aircraft should be flown on a downwind heading to one side of the selected point at a distance equal to the desired radius of turn. When any significant wind exists, it will be necessary to roll into the initial bank at a rapid rate so that the steepest bank is attained abeam of the point when the aircraft is headed directly downwind. By entering the maneuver while heading directly downwind, the steepest bank can be attained immediately. Thus, if a maximum bank of 45° is desired, the initial bank is 45° if the aircraft is at the correct distance from the point. Thereafter, the bank is shallowed gradually until the point is reached at which the aircraft is headed directly upwind. At this point, the bank should be gradually steepened until the steepest bank is again attained when heading downwind at the initial point of entry.

Just as S-turns require that the aircraft be turned into the wind in addition to varying the bank, so do turns around a point. During the downwind half of the circle, the aircraft’s nose is progressively turned toward the inside of the circle; during the upwind half, the nose is progressively turned toward the outside. The downwind half of the turn around the point may be compared to the downwind side of the S-turn across a road; the upwind half of the turn around a point may be compared to the upwind side of the S-turn across a road.

As the pilot becomes experienced in performing turns around a point and has a good understanding of the effects of wind drift and varying the bank angle and wind correction angle as required, entry into the maneuver may be from any point. When entering the maneuver at a point other than downwind, however, the radius of the turn should be carefully selected. Be sure to take into account the wind velocity and groundspeed so that an excessive bank is not required later on to maintain the proper ground track. The flight instructor should place particular emphasis on the effect of an incorrect initial bank.

Common errors in the performance of turns around a point are:

Failure to clear the area adequately.
Failure to establish appropriate bank on entry.
Failure to recognize wind drift.
Inadequate bank angle and/or inadequate wind correction angle on the downwind portion of the circle, resulting in drift away from the reference point.
Excessive bank and/or inadequate wind correction angle on the upwind side of the circle, resulting in drift towards the reference point.
Gaining or losing altitude.
Inability to maintain a constant airspeed.
Inadequate visual lookout for other aircraft.
Inability to direct attention outside the aircraft while maintaining precise aircraft control.

Rectangular Course

Filed Under: WSC Ground Reference Maneuvers

Normally, the first ground reference maneuver introduced to the pilot is the rectangular course. Reference Figure 9-4 throughout this rectangular course section.

The rectangular course is a training maneuver in which the ground track of the aircraft is equidistant from all sides of a selected rectangular area on the ground. The maneuver simulates the conditions encountered in an airport traffic pattern. While performing the maneuver, the altitude and airspeed should be held constant.

The maneuver assists the student pilot in perfecting:

Practical application of the turn.
Division of attention between the flightpath, ground objects, and the handling of the aircraft.
Timing of the start of a turn so that the turn is fully established at a definite point over the ground.
Timing of the recovery from a turn so that a definite ground track is maintained.
Establishing a ground track and determining the appropriate “crab” angle.

As for other ground track maneuvers, one of the objectives is to develop division of attention between the flightpath and ground references while controlling the aircraft and watching for other aircraft in the vicinity. Another objective is to develop recognition of drift toward or away from a line parallel to the intended ground track. This is helpful in recognizing drift toward or away from an airport runway during the various legs of the airport traffic pattern.

For this maneuver, a square or rectangular field (bound on four sides by section lines or roads that are approximately one-half mile in length) should be selected away from other air traffic. The aircraft should be fl own parallel to and at a uniform distance just to the outside of the field boundaries, not quite above the boundaries so that the flightpath may be easily observed from either seat by looking out the side of the aircraft. The closer the track of the aircraft is to the field boundaries, the steeper the bank necessary at the turning points. The distance of the ground track from the edges of the field should be the same regardless of whether the course is fl own to the left or right. Turns should be started when the aircraft is abeam the corner of the field boundaries, and the bank normally should not exceed 45°. These should be the determining factors in establishing the distance from the boundaries for performing the maneuver.

Although the rectangular course may be entered from any direction, this discussion assumes entry on a downwind. On the downwind leg, the wind is a tailwind and results in increased groundspeed. Consequently, the turn onto the next leg is entered with a fairly fast rate of roll-in with relatively steep bank. As the turn progresses, the bank angle is reduced gradually because the tailwind component is diminishing, resulting in a decreasing groundspeed.

During and after the turn onto this leg (the equivalent of the base leg in a traffic pattern), the wind tends to drift the aircraft away from the field boundary. To compensate for the drift, the amount of turn is more than 90°.

The rollout from this turn must be such that as the wings become level, the aircraft is turned slightly toward the field and into the wind to correct for drift. The aircraft should again be the same distance from the field boundary and at the same altitude as on other legs. The base leg should be continued until the upwind leg boundary is being approached. Once more, the pilot should anticipate drift and turning radius. Since drift correction was held on the base leg, it is necessary to turn less than 90° to align the aircraft parallel to the upwind leg boundary. This turn should be started with a medium bank angle with a gradual reduction to a shallow bank as the turn progresses. The rollout should be timed to assure paralleling the boundary of the field as the wings become level. [Figure 9-5]

Figure 9-5. Pilot’s view coming out of a left turn to straighten out for the rectangular leg on the lower left. The next left turn of the rectangular course is shown by the red line for reference.

While the aircraft is on the upwind leg, the next field boundary should be observed as it is being approached to plan the turn onto the crosswind leg. Since the wind is a headwind on this leg, it reduces the aircraft’s groundspeed and tries to drift the aircraft toward the field during the turn onto the crosswind leg. For this reason, the roll-in to the turn must be slow and the bank relatively shallow to counteract this effect. As the turn progresses, the headwind component decreases, allowing the groundspeed to increase. Consequently, the bank angle and rate of turn are increased gradually to assure that upon completion of the turn, the crosswind ground track continues the same distance from the edge of the field. Completion of the turn with the wings level should be accomplished at a point aligned with the upwind corner of the field.

As the wings are rolled level, the proper drift correction is established with the aircraft turned into the wind with a change in heading of less than 90°. If the turn has been made properly, the field boundary will again be the same distance as it was in the previous legs. While on the crosswind leg, the wind correction angle should be adjusted as necessary to maintain a uniform distance from the field boundary.

As the next field boundary is being approached, the pilot should plan the turn onto the downwind leg. Since a wind correction angle is being held into the wind and away from the field while on the crosswind leg, this next turn requires a turn of more than 90°. Since the crosswind becomes a tailwind, causing the groundspeed to increase during this turn, the bank initially should be medium and progressively increased as the turn proceeds. To complete the turn, the rollout must be timed so that the wings become level at a point aligned with the crosswind corner of the field just as the longitudinal axis of the aircraft again becomes parallel to the field boundary. The distance from the field boundary should be the same as from the other sides of the field.

Usually, drift should not be encountered on the upwind or the downwind leg, but it may be difficult to find a situation where the wind is blowing exactly parallel to the field boundaries. This would make it necessary to use a slight wind correction angle on all the legs. It is important to anticipate the turns to correct for groundspeed, drift, and turning radius. When the wind is behind the aircraft, the turn must be faster and steeper; when it is ahead of the aircraft, the turn must be slower and shallower. These same techniques apply while flying in airport traffic patterns.

Common errors in the performance of rectangular courses are:

Failure to adequately clear the area.
Failure to establish proper altitude prior to entry (typically entering the maneuver while descending).
Failure to establish appropriate wind correction angle, resulting in drift.
Gaining or losing altitude.
Poor coordination (typically gaining or losing airspeed during the turns).
Abrupt control usage.
Inability to divide attention adequately between aircraft control and maintaining ground track.
Improper timing in beginning and recovering from turns.
Inadequate visual lookout for other aircraft.

Maneuvering by Reference to Ground Objects and Drift and Ground Track Control

Filed Under: WSC Ground Reference Maneuvers

The early part of a pilot’s training is conducted at relatively high altitudes for the purpose of developing technique, knowledge of maneuvers, coordination, feel, and the handling of the aircraft in general. This training requires that most of the pilot’s attention be given to the actual handling of the aircraft, the results of control pressures on the action, and attitude of the aircraft.

As soon as the pilot shows proficiency in the fundamental maneuvers, it is necessary that he or she be introduced to ground reference maneuvers requiring attention beyond practical application and current knowledge base.

It should be stressed that during ground reference maneuvers, it is equally important that previously learned basic flying technique be maintained. The flight instructor should not allow any relaxation of the student’s previous standard of technique simply because a new factor is added. This requirement should be maintained throughout the student’s progress from maneuver to maneuver. Each new maneuver should embody some advanced knowledge and include principles of the preceding maneuver in order to maintain continuity. Each new skill introduced should build on one already learned so that orderly, consistent progress can be made.

Maneuvering by Reference to Ground Objects

Ground track or ground reference maneuvers are performed at relatively low altitudes while applying wind drift correction as needed to follow a predetermined track or path over the ground. These maneuvers are designed to develop the ability to control the aircraft and to recognize and correct for the effect of wind, while dividing attention among other matters. This requires planning ahead of the aircraft, maintaining orientation in relation to ground objects, flying appropriate headings to follow a desired ground track, and being cognizant of other air traffic in the immediate vicinity.

Ground reference maneuvers should be flown at an altitude of approximately 500 to 1,000 feet above ground level (AGL). The actual altitude will depend on the ability to reach a safe landing area if there is an engine failure during the maneuver and the type of air in which the maneuvers are being fl own. If there is significant vertical movement of the air, higher altitudes should be used to avoid the possibility of flying below 400 feet AGL, the minimum altitude recommended in the Practical Test Standards (PTS).

Overall, the following factors should be considered in determining the appropriate altitudes for ground reference maneuvers:

The speed with relation to the ground should not be so apparent that events happen too rapidly.
The radius of the turn and the path of the aircraft over the ground should be easily noted and changes planned and effected as circumstances require.
Drift should be easily discernable but should not overtax the student in making corrections.
Objects on the ground should appear in their proportion and size.
The altitude should be low enough to render any gain or loss apparent to the student, but not recommended lower than 400 feet above the highest obstruction and in no case lower than 500 feet above any person, vessel, vehicle, or structure.

During these maneuvers, both the instructor and the student should be alert for available forced-landing fields. The area chosen should be away from communities, livestock, or groups of people to prevent becoming an annoyance or hazard. Due to the altitudes at which these maneuvers are performed, there is little time available to search for a suitable field for landing in the event the need arises.

Drift and Ground Track Control

Whenever an object is free from the ground, it is affected by the medium surrounding it. This means that a free object moves in whatever direction and speed that the medium moves.

For example, if a powerboat were crossing a still river, the boat could head directly to a point on the opposite shore and travel on a straight course to that point without drifting. However, if the river were fl owing swiftly, the water current would require consideration. That is, as the boat progresses forward on its own power, it must also move upstream at the same rate the river is moving it downstream. This is accomplished by angling the boat upstream sufficiently to counteract the downstream fl ow. If this is done, the boat follows the desired track across the river from the departure point directly to the intended destination point. If the boat is not headed sufficiently upstream, it would drift with the current and run aground at some point downstream on the opposite bank. [Figure 9-1]

Figure 9-1. Wind drift and wind correction angle (crab angle).

As soon as an aircraft becomes airborne, it is free of ground friction. Its path is then affected by the air mass in which it is flying; therefore, the aircraft (like the boat) does not always track along the ground in the exact direction that it is headed. When flying with the longitudinal axis of the aircraft aligned with a road, it may be noted that the aircraft gets closer to or farther from the road without any turn having been initiated by the pilot. This would indicate that the air mass is moving sideward in relation to the aircraft. Since the aircraft is flying within this moving body of air (wind), it moves or drifts with the air in the same direction and speed, just like the boat moved with the river current.

When flying straight and level and following a selected ground track, the preferred method of correcting for wind drift is to head the aircraft (wind correction angle) sufficiently into the wind to cause the aircraft to move forward into the wind at the same rate the wind is moving it sideways. Depending on the wind velocity, this may require a large wind correction angle or one of only a few degrees. This wind correction angle is also commonly known as the crab angle. When the drift has been neutralized, the aircraft follows the desired ground track.

To understand the need for drift correction during flight, consider a flight with a wind velocity of 20 knots from the left and 90° to the direction the aircraft is headed. After 1 hour, the body of air in which the aircraft is flying has moved 20 nautical miles (NM) to the right. Since the aircraft is moving with this body of air, it too has drifted 20 NM to the right. In relation to the air, the aircraft moved forward; but in relation to the ground, it moved forward as well as 20 NM to the right.

There are times when the pilot needs to correct for drift while in a turn. [Figure 9-2]

Figure 9-2. Effect of wind during a turn.

Throughout the turn, the wind is acting on the aircraft from constantly changing angles. The relative wind angle and speed govern the time it takes for the aircraft to progress through any part of a turn. This is due to the constantly changing groundspeed. When the aircraft is headed into the wind, the groundspeed is decreased; when headed downwind, the groundspeed is increased. Through the crosswind portion of a turn, the aircraft must be turned sufficiently into the wind to counteract drift.

To follow a desired circular ground track, the wind correction angle must be varied in a timely manner because of the varying groundspeed as the turn progresses. The faster the groundspeed, the faster the wind correction angle must be established; the slower the groundspeed, the slower the wind correction angle may be established. It can be seen then that the steepest bank and fastest rate of turn should be made on the downwind portion of the turn and the shallowest bank and slowest rate of turn on the upwind portion.

The principles and techniques of varying the angle of bank to change the rate of turn and wind correction angle for controlling wind drift during a turn are the same for all ground track maneuvers involving changes in direction of fl ight. When there is no wind, it should be simple to fl y along a ground track with an arc of exactly 180° and a constant radius because the fl ightpath and ground track would be identical. This can be demonstrated by approaching a road at a 90° angle and, when directly over the road, rolling into a medium-banked turn. Then, maintaining the same angle of bank throughout the 180° of turn. [Figure 9-2]

To complete the turn, the rollout should be started at a point where the wings become level as the aircraft again reaches the road at a 90° angle and is directly over the road just as the turn is completed. This would be possible only if there were absolutely no wind and if the angle of bank and the rate of turn remained constant throughout the entire maneuver.

If the turn were made with a constant angle of bank and a wind blowing directly across the road, it would result in a constant radius turn through the air. However, the wind effects would cause the ground track to be distorted from a constant radius turn or semicircular path. The greater the wind velocity, the greater the difference between the desired ground track and the flightpath. To counteract this drift, the flightpath can be controlled by the pilot in such a manner as to neutralize the effect of the wind and cause the ground track to be a constant radius semicircle.

The effects of wind during turns can be demonstrated after selecting a road, railroad, or other ground reference that forms a straight line parallel to the wind. Fly into the wind directly over and along the line and then make a turn with a constant medium angle of bank for 360° of turn. [Figure 9-3]

Figure 9-3. Effect of wind during turns.

The aircraft returns to a point directly over the line but slightly downwind from the starting point, the amount depending on the wind velocity and the time required to complete the turn. The path over the ground is an elongated circle, although in reference to the air it is a perfect circle. Straight flight during the upwind segment after completion of the turn is necessary to bring the aircraft back to the starting position.

A similar 360° turn may be started at a specific point over the reference line, with the aircraft headed directly downwind. In this demonstration, the effect of wind during the constant banked turn drifts the aircraft to a point where the line is re-intercepted, but the 360° turn is completed at a point downwind from the starting point.

Another reference line which lies directly crosswind may be selected and the same procedure repeated. If wind drift is not corrected, the aircraft is headed in the original direction at the completion of the 360° turn, but has drifted away from the line a distance dependent on the amount of wind.

From these demonstrations, it can be seen where and why it is necessary to increase or decrease the angle of bank and the rate of turn to achieve a desired track over the ground. The principles and techniques involved can be practiced and evaluated by the performance of the ground track maneuvers discussed in this chapter.

Other Airspace Areas

Filed Under: WSC The National Airspace System

Other airspace areas is a general term referring to the majority of the remaining airspace. It includes:

Airport advisory areas
Military training routes (MTRs)
Temporary flight restrictions (TFRs)
Terminal Radar Service Areas
National security areas

Local Airport Advisory

A local airport advisory is an area within 10 statute miles (SM) of an airport where a control tower is not operating, but where a flight service station (FSS) is located. At these locations, the FSS provides advisory service to arriving and departing aircraft. See AIM section 3-5-1 for more information on using the local airport flight station services.

Military Training Routes (MTRs)

National security depends largely on the deterrent effect of our airborne military forces. To be proficient, the military services must train in a wide range of airborne tactics. One phase of this training involves “low level” combat tactics. The required maneuvers and high speeds are such that they may occasionally make the see-and-avoid aspect of VFR flight more difficult without increased vigilance in areas containing such operations. In an effort to ensure the greatest practical level of safety for all flight operations, the Military Training Route (MTR) program was conceived.

These routes are usually established below 10,000 feet MSL for operations at speeds in excess of 250 knots. Some route segments may be defined at higher altitudes for purposes of route continuity. Routes are identified as IFR (IR), and VFR (VR), followed by a number. MTRs with no segment above 1,500 feet AGL are identified by four numeric characters (e.g., IR1206, VR1207). MTRs that include one or more segments above 1,500 feet AGL are identified by three numeric characters (e.g., IR206, VR207). IFR Low Altitude En Route Charts depict all IR routes and all VR routes that accommodate operations above 1,500 feet AGL. IR routes are conducted in accordance with IFR regardless of weather conditions.

MTRs are usually indicated with a gray line on the sectional chart. A WSC aircraft pilot flying in the area of VRs or IRs should question the briefer during the weather brief to find out if any of the routes are in use, and a possible time frame for opening and closing. While it is true that the WSC aircraft pilot has the right of way, the WSC aircraft will generally come out worse in a midair conflict with a fast-moving military aircraft. MTRs, such as the example depicted in Figure 8-17, are also further defined on sectional charts.

Temporary Flight Restrictions (TFRs)

TFRs are put into effect when traffic in the airspace would endanger or hamper air or ground activities in the designated area. For example, a forest fire, chemical accident, flood, or disaster-relief effort could warrant a TFR, which would be issued as a Notice to Airmen (NOTAM). The NOTAM begins with the phrase “FLIGHT RESTRICTIONS” followed by the location, effective time period, area defined in statute miles, and altitudes affected, which aircraft flying in the area must avoid. The NOTAM also contains the FAA coordination facility and telephone number, the reason for the restriction, and any other information deemed appropriate. The pilot should check NOTAMs as part of flight planning.

The reasons for establishing a temporary restriction are to:

Protect persons and property in the air or on the surface from an existing or imminent hazard;
Provide a safe environment for the operation of disaster relief aircraft;
Prevent unsafe congestion of sightseeing aircraft above an incident or event, which may generate a high degree of public interest;
Protect declared national disasters for humanitarian reasons;
Protect the President, Vice President, or other public figures; and
Provide a safe environment for space agency operations.

It is a pilot’s responsibility to be aware of TFRs in his or her proposed area of flight. One way to check is to visit the FAA website, www.tfr.faa.gov, and verify that there is not a TFR in the area. Another resource is to ask the flight briefer at 800-WX-BRIEF during the preflight briefing.

Terminal Radar Service Areas (TRSA)

Terminal Radar Service Areas (TRSA) are areas where participating pilots can receive additional radar services. The purpose of the service is to provide separation between all IFR operations and participating VFR aircraft.

The primary airport(s) within the TRSA become(s) Class D airspace. The remaining portion of the TRSA overlies other controlled airspace, which is normally Class E airspace beginning at 700 or 1,200 feet and established to transition to/ from the en-route terminal environment. TRSAs are depicted on VFR sectional charts and terminal area charts with a solid black line and altitudes for each segment. The Class D portion is charted with a blue segmented line. Participation in TRSA services is voluntary; however, pilots operating under VFR are encouraged to contact the radar approach control and take advantage of TRSA service. Operations inside the TFR area must be conducted under the provisions of a waiver. Should such an operation be contemplated, the WSC aircraft pilot should consult with the local Flight Service District Office (FSDO) well in advance of the event.

National Security Areas (NSAs)

NSAs consist of airspace with defined vertical and lateral dimensions established at locations where there is a requirement for increased security and safety of ground facilities. Flight in NSAs may be temporarily prohibited by regulation under the provisions of 14 CFR part 99, and prohibitions are disseminated via NOTAM.

Published VFR Routes

Published VFR routes are for transitioning around, under, or through some complex airspace. Terms such as VFR flyway, VFR corridor, Class B airspace, VFR transition route, and terminal area VFR route have been applied to such routes. These routes are generally found on VFR terminal area planning charts.

Flight Over Charted U.S. Wildlife Refuges, Parks, and Forest Service Areas

The landing of aircraft is prohibited on lands or waters administered by the National Park Service, U.S. Fish and Wildlife Service, or U.S. Forest Service without authorization from the respective agency. Exceptions include:

When forced to land due to an emergency beyond the control of the operator;
At officially designated landing sites; or
An approved official business of the Federal Government.

Pilots are requested to maintain a minimum altitude of 2,000 feet above the surface of the following: national parks, monuments, seashores, lakeshores, recreation areas, and scenic riverways administered by the National Park Service, National Wildlife Refuges, Big Game Refuges, Game Ranges, and Wildlife Ranges administered by the U.S. Fish and Wildlife Service and wilderness and primitive areas administered by the U.S. Forest Service.

WSC Operations

WSC preflight planning should include a review of the airspace that is flown. A local flight may be close to the field and include only Class G and Class E airspace. Minimum visibility and cloud clearance may be the only requirements to be met. However, a radio to communicate to the airport traffic and an altimeter to fly at the proper airport pattern altitude is recommended.

If flying to control tower airports or through Class B, C, or D airspace, determine if the WSC meets all of the equipment requirements of that airspace. [Figure 8-5] Also review qualifications to determine if the minimum pilot requirements of the airspace are met. If the minimum aircraft and/or pilot requirements of the airspace are not met, then the preflight planning should include a course around the airspace. Extra time and fuel is required for the circumnavigation and should be taken into consideration prior to departure.

Figure 8-5. Requirements for airspace operation.

WSC and Air Traffic Control

In nontowered airspace, airspace separation from other aircraft is the responsibility of the pilot. Separation from higher speed traffic may require flightpaths different than faster traffic. For flight and communicating with a control tower, the WSC pilot may be asked to expedite or deviate from a traditional course. The WSC pilot must work with ATC in advising of the airspeed and surface wind limitations. Safe operation in controlled airspace requires that the controller understand the performance and limits of the WSC aircraft.

Navigating the Airspace

Knowledge of airspace dimensions, requirements to enter the airspace, and geographical location of the airspace is the responsibility of all pilots. The current sectional chart is the primary official tool to determine the airspace flying within or avoiding.

Pilotage is navigation by reference to landmarks to determine location and the location of airspace. Pilotage is the best form of navigation to ensure that you avoid airspace not authorized to enter. Locating your position on the sectional chart and locating/identifying the airspace you want to enter/avoid requires preflight planning on the ground and situational awareness in the air.

For all flights, pilots must be sure to have enough fuel to complete the flight. For longer cross-country flights, this requires the pilot to check winds aloft and calculate the groundspeed for the planned altitude and forecast wind. The resultant time to the destination and the fuel consumption determines the fuel required to make the flight. This preflight planning is especially important for slower WSC aircraft because increased headwind components provide significant time increases to get to fuel stops than faster aircraft. Although 14 CFR section 91.151 requires airplanes to have at least 30 minutes of reserve fuel for an intended fuel stop; this minimum is also recommended for WSC aircraft. The Pilot’s Handbook of Aeronautical Knowledge chapter on navigation provides procedures in navigation, plotting a course, determining groundspeed for the predicted wind, headings and the required fuel for intended legs of the flight. For any cross-country flight, a flight log should be used and the planned groundspeed should be compared to the actual GPS groundspeed measured in flight. If the GPS groundspeed is lower than the planned groundspeed, the time en route and the fuel reserves must be evaluated to assure the WSC aircraft does not run out of fuel during the flight.

GPS is a very popular form of navigation used by WSC pilots. The GPS receiver is small, simple to use, and inexpensive compared to other forms of electronic (radio) navigation. Simple modes of operation provide actual groundspeed and time to a waypoint. More sophisticated GPSs have aviation databases and provide the pilot a considerable amount of information about airports and airspace. When using GPS to determine airspace or airport position, boundaries, and/ or information, the aviation database in the GPS may not exactly match the information as depicted on the sectional chart. If there is a difference between the sectional chart and GPS information, the sectional chart should be considered correct.

A WSC pilot using GPS should ensure that the batteries are fresh and the aviation database is current. Never rely on the GPS as a primary navigation system. Pilotage using the sectional chart is the primary navigation system when flying beyond visual range of a familiar airport. The GPS is used only as a backup aid for navigation. With proper preflight planning and constant evaluation of the planned verses actual flight performance, cross-country flight is practical in the NAS for WSC pilots.

Special Use Airspace

Filed Under: WSC The National Airspace System

Special use airspace is the designation for airspace in which certain activities must be confined, or where limitations may be imposed on aircraft operations that are not part of those activities.

Special use airspace usually consists of:

Prohibited areas
Restricted areas
Warning areas
Military operation areas (MOAs)
Alert areas
Controlled firing areas
Parachute jump areas

Except for controlled firing areas, special use airspace areas are depicted on visual sectional charts. [Figure 8-11] Controlled firing areas are not charted because their activities are suspended immediately when spotter aircraft, radar, or ground lookout positions indicate an aircraft might be approaching the area. Nonparticipating aircraft are not required to change their flightpaths. Special use airspace areas are shown in their entirety (within the limits of the chart), even when they overlap, adjoin, or when an area is designated within another area. The areas are identified by type and identifying name or number, positioned either within or immediately adjacent to the area. [Figure 8-11]

Figure 8-11. Special use airspace designations as appear on sectional charts.

Prohibited, restricted or warning areas; alert areas; and MOAs are further defined with tables on sectional charts for their altitudes, time of use, controlling agency/contact facility and controlling agency contact frequency. [Figure 8-12]

Figure 8-12. Example of the additional information provided on sectional charts for special use airspace.

Prohibited Areas

Prohibited areas contain airspace of defined dimensions within which the flight of aircraft is prohibited. Such areas are established for security or other reasons associated with the national welfare. These areas are published in the Federal Register and are depicted on sectional charts. The area is charted as a “P” followed by a number (e.g., “P-56 A and B”). [Figure 8-13]

Figure 8-13. Prohibited area in Washington, D.C., on a sectional chart.

Restricted Areas

Restricted areas are areas where operations are hazardous to nonparticipating aircraft and contain airspace within which the flight of aircraft, while not wholly prohibited, is subject to restrictions. Activities within these areas must be confined because of their nature, or limitations may be imposed upon aircraft operations that are not a part of those activities, or both. Restricted areas denote the existence of unusual, often invisible, hazards to aircraft (e.g., artillery firing, aerial gunnery, or guided missiles). Penetration of restricted areas is illegal without authorization from the using or controlling agency may be extremely hazardous to the aircraft and its occupants. ATC facilities apply the following procedures:

If the restricted area is not active and has been released to the Federal Aviation Administration (FAA), the ATC facility will allow the aircraft to operate in the restricted airspace without issuing specific clearance for it to do so.
If the restricted area is active and has not been released to the FAA, the ATC facility will issue a clearance which will ensure the aircraft avoids the restricted airspace.

Restricted areas are charted with an “R” followed by a number (e.g., “R-4803 and R-4810”) and are depicted on the sectional charts. [Figure 8-14]

Figure 8-14. Special use airspace: restricted and MOA examples.

Warning Areas

Warning areas consist of airspace which may contain hazards to nonparticipating aircraft in international airspace. The activities may be much the same as those for a restricted area. Warning areas are established beyond the three-mile limit and are depicted on sectional charts.

Military Operations Areas (MOAs)

MOAs consist of airspace of defined vertical and lateral limits established for the purpose of separating certain military training activity from IFR traffic. There is no restriction against a pilot operating VFR in these areas; however, a pilot should be alert since training activities may include acrobatic and abrupt maneuvers. MOAs are depicted by name and with defined boundaries on sectional, VFR terminal area, and en route low altitude charts and are not numbered (e.g., “CHURCHILL HIGH MOA,” “CHURCHILL LOW MOA”). [Figure 8-14] MOA is further defined on sectional charts with times of operation, altitudes affected, and the controlling agency frequency for the MOA to contact for current activity. [Figure 8-15]

Figure 8-15. MOA is further defined on sectional charts with times of operation, altitudes affected, and the controlling agency to contact for current activity.

Alert Areas

Alert areas are depicted on sectional charts with an “A” followed by a number (e.g., “A-211” as in Figure 8-16) to inform nonparticipating pilots of areas that may contain a high volume of pilot training or an unusual type of aerial activity. Pilots should be particularly alert when flying in these areas. All activity within an alert area shall be conducted in accordance with regulations, without waiver. Pilots of participating aircraft, as well as pilots transiting the area, shall be equally responsible for collision avoidance.

Controlled Firing Areas

Controlled firing areas contain military activities, which, if not conducted in a controlled environment, could be hazardous to nonparticipating aircraft. The difference between controlled firing areas and other special use airspace is that activities must be suspended when a spotter aircraft, radar, or ground lookout position indicates an aircraft might be approaching the area.

Parachute Jump Areas

Parachute jump areas are published in the Airport/ Facility Directory (A/FD). Sites that are used frequently are depicted on sectional charts. Each pilot should listen to the appropriate airport radio frequency for parachute operations and be alert for aircraft which might be conducting parachute operations.

Uncontrolled and Controlled Airspace

Filed Under: WSC The National Airspace System

Class G Airspace

Class G or uncontrolled airspace is the portion of the airspace that has not been designated as Class A, B, C, D, or E. Class G airspace extends from the surface to the base of controlled airspace (Class B, C, D, and E) above it as shown in Figures 8-2 and 8-3.

Figure 8-2. Class G uncontrolled airspace and Class E controlled airspace.

Figure 8-3. Class G airspace extends from the surface to the base of controlled airspace (Class B, C, D, and E).

Most Class G airspace is overlaid with Class E airspace, beginning at either 700 or 1,200 feet above ground level (AGL). In remote areas of the United States, Class G airspace extends above 700 and 1,200 AGL to as high as 14,500 feet before the Class E airspace begins. [Figure 8-2] The pilot is advised to consult the appropriate sectional chart to ensure that he or she is aware of the airspace limits prior to flight in an unfamiliar area. [Figure 8-4]

Figure 8-4. Class G airspace as shown on a sectional chart.

There are no communications, entry, equipment, or minimum pilot certificate requirements to fly in uncontrolled Class G airspace unless there is a control tower. [Figure 8-5]

If operations are conducted at an altitude of < 1,200 feet AGL, the pilot must remain clear of clouds. If the operations are conducted more than 1,200 feet AGL but less than 10,000 feet mean sea level (MSL), cloud clearances are 1,000 feet above, 500 feet below, and 2,000 feet horizontally from any cloud(s). A popular mnemonic tool used to remember basic cloud clearances is “C152,” a popular fixed-wing training aircraft. In this case, the mnemonic recalls, “Clouds 1,000, 500, and 2,000.”

Visibility in Class G airspace below 10,000 MSL day flight is one statute mile (SM) for private pilots and three SM for sport pilots. See Figure 8-6 for specific Class G weather minimums for WSC pilots.

Figure 8-6. Basic weather minimums for WSC operations in the different classes of airspace.

Controlled Airspace

Controlled airspace is a generic term that covers the different classifications of airspace and defined dimensions within which ATC service is provided in accordance with the airspace classification. Controlled airspace consists of:

Class E
Class D
Class C
Class B
Class A

Class E Airspace

Generally, if the airspace is not Class A, B, C, or D, and is controlled airspace, then it is Class E airspace. Class E airspace extends upward from either the surface or a designated altitude to the overlying or adjacent controlled airspace. [Figures 8-3 and 8-7] Also Class E is federal airways beginning at 1,200 feet AGL extending 4 nautical miles (NM) on each side, extending up to 18,000 feet.

Unless designated at a lower altitude, Class E airspace begins at 1,200 AGL over the United States, including that airspace overlying the waters within 12 NM of the coast of the 48 contiguous states and Alaska, and extends up to but not including 18,000 feet.

There are no specific communications requirements associated with Class E airspace [Figure 8-5]; however, some Class E airspace locations are designed to provide approaches for instrument approaches, and a pilot would be prudent to ensure that appropriate communications are established when operating near those areas.

If WSC aircraft operations are being conducted below 10,000 feet MSL, minimum visibility requirements are three statute miles and basic VFR cloud clearance requirements are 1,000 feet above, 500 feet below, and 2,000 feet horizontal (remember the C152 mnemonic). Operations above 10,000 feet MSL for private pilots of WSC aircraft require minimum visibility of five statute miles and cloud clearances of at least 1,000 feet above, 1,000 feet below, and one statute mile horizontally. [Figure 8-5] See Figure 8-6 for specific VFR visibility requirements.

Towered Airport Operations

All student pilots must have an endorsement to operate within Class B, C, and D airspace and within airspace for airports that have a control tower, per 14 CFR section 61.94 or 14 CFR section 61.95. Only private pilot students can operate within Class B airspace with the proper endorsements per 14 CFR section 61.95. Sport pilots must also have an endorsement per 14 CFR section 61.325 to operate within Class B, C, and D airspace and within airspace for airports with a control tower. [Figure 8-5] All students and Sport pilots have further restrictions regarding the specific Class B airports out of which they may operate, per 14 CFR section 91.131.

Class D Airspace

Class D is that airspace from the surface to 2,500 feet AGL (but charted in MSL) surrounding smaller airports with an operational control tower. [Figures 8-3 and 8-8] The configuration of each Class D airspace area is individually tailored. When instrument procedures are published, the airspace is normally designed to contain the procedures.

Unless otherwise authorized, each aircraft must establish two-way radio communications with the ATC facility providing air traffic services prior to entering the airspace and thereafter maintain those communications while in the airspace. Radio contact should be initiated far enough from the Class D airspace boundary to preclude entering the Class D airspace before two-way radio communications are established. It is important to understand that if the controller responds to the initial radio call without using the WSC aircraft’s call sign, radio communications have not been established, and the WSC aircraft may not enter the Class D airspace.

Many airports associated with Class D airspace do not operate a control tower on a 24-hour-a-day basis. When not in operation, the airspace will normally revert to Class E or G airspace, with no communications requirements. Refer to the AF/D for specific hours of operation airports.

The minimum visibility requirements for Class D airspace are three statute miles; cloud clearances are the 1,000 above, 500 below and 2,000 vertical. [Figure 8-6]

Class C Airspace

Class C airspace normally extends from the surface to 4,000 feet above the airport elevation surrounding those airports having an operational control tower, that are serviced by a radar approach control, and with a certain number of IFR and passenger enplanements (larger airline operations). [Figures 8-3 and 8-9] This airspace is charted in feet MSL, and is generally of a five NM radius surface area that extends from the surface to 4,000 feet above the airport elevation, and a 10 NM radius area that extends from 1,200 feet to 4,000 feet above the airport elevation. There is also a noncharted outer area with a 20 NM radius, which extends from the surface to 4,000 feet above the primary airport, and this area may include one or more satellite airports. [Figure 8-9]

WSC aircraft can fly into Class C airspace by contacting the control tower first, establishing communications (same as Class D), and having an altitude encoding transponder. Aircraft can enter Class C airspace without a transponder if prior permission from ATC is received 1 hour before entry, per 14 CFR section 91.215(d)(3). Aircraft may fly under the Class C upper tier of airspace without a transponder but not over the top of Class C airspace lateral boundaries.

Cloud clearances in Class C airspace are the same as Class D airspace: minimum visibility of three statute miles, and a minimum distance from clouds of 1,000 feet above, 500 feet below, and 2,000 feet horizontal.

Since Class C has significant air traffic, many with larger airplanes creating stronger vortices, the pilot must be aware that the chance of encountering catastrophic wingtip vortices is greater at airports with larger air traffic.

Class B Airspace

Class B airspace is generally airspace from the surface to 10,000 feet MSL surrounding the nation’s busiest airports in terms of IFR operations or passenger enplanements. [Figures 8-3 and 8-10] The configuration of each Class B airspace area is individually tailored and consists of a surface area and two or more additional layers (some Class B airspace areas resemble upside-down wedding cakes), and is designed to contain all published instrument procedures once an aircraft enters the airspace.

Equipment requirements are the same as for Class C airspace; however, due to air traffic congestion, the WSC aircraft pilot requesting entry to Class B airspace may be denied entry. Since aircraft operating in Class B airspace have a radar signature and ATC provides aircraft separation, there is a difference in the cloud clearance requirements. Visibility remains three statute miles, but minimum cloud clearance requirement is to remain clear of clouds. [Figure 8-6]

Airspace Above 10,000′ MSL and Below 18,000′

For WSC aircraft flying above 10,000 feet MSL, the visibility must be greater than 5 SM and cloud clearances increase to 1,000 feet below, 1,000 feet above, and 1 SM horizontal. If the WSC aircraft was not certificated with an electrical system, an altitude encoding transponder is required per 14 CFR section 91.215.

Oxygen is required for the pilot above 12,500 MSL up to and including 14,000 feet MSL if the flight at those levels is more than 30 minutes duration. At altitudes above 14,000 feet MSL, oxygen is required for the pilot during the entire flight time at those altitudes. At altitudes above 15,000 feet MSL, each occupant of the aircraft must be provided with supplemental oxygen.

Class A Airspace

Class A airspace is generally the airspace from 18,000 feet MSL up to and including FL 600, including the airspace overlying the waters within 12 NM of the coast of the 48 contiguous states and Alaska. Unless otherwise authorized, all operations in Class A airspace are conducted under IFR. Class A airspace is not applicable to WSC pilots.