Eights Around Pylons
Eights around pylons is a ground reference maneuver with the same principles and techniques of correcting for wind drift as used in
turns around a point and the same objectives as other ground track maneuvers. Eights around pylons utilizes two ground reference
points called “pylons.” Turns around each pylon are made in opposite directions to follow a ground track in the form of a figure 8.
[Figure 7-9]
Figure 7-9. Eights around pylons.
The pattern involves flying downwind between the pylons and upwind outside of the pylons. It may include a short period of straight -
and-level flight while proceeding diagonally from one pylon to the other. The pylons should be on a line perpendicular to the wind.
he maneuver should be started with the airplane on a downwind heading while passing mid-way between the pylons. The distance
between the pylons and the wind velocity determines the initial angle of bank required to maintain a constant turn radius from the
pylons during each turn. The steepest banks are necessary just after each turn entry and just before the rollout from each turn where
the airplane is headed downwind and the groundspeed is highest. The shallowest banks are when the airplane is headed directly
upwind and the groundspeed is lowest.
As in other ground reference maneuvers, the rate at which the bank angle changes depends on the wind velocity. If the airplan e
proceeds diagonally from one turn to the other, the rollout from each turn needs to be completed on the proper heading with sufficient
wind correction angle to ensure that after brief straight-and-level flight, the airplane arrives at the point where a turn of the same
radius can be made around the other pylon. The straight-and-level flight segments should be tangent to both circular patterns.
Common Errors
Common errors in the performance of elementary eights are:
1. Failure to adequately clear the surrounding area for safety hazards, initially and throughout the maneuver.
2. Poor selection of ground references.
3. Failure to establish a constant, level altitude prior to entering the maneuver.
4. Failure to maintain adequate altitude control during the maneuver.
5. Failure to properly assess wind direction.
6. Failure to properly execute constant-radius turns.
7. Failure to manipulate the flight controls in a smooth and continuous manner.
8. Failure to establish the appropriate wind correction angles.
9. Failure to apply coordinated aileron and rudder pressure, resulting in slips or skids.
10. Failure to maintain orientation as the maneuver progresses.
Eights on Pylons
The eights on pylons is the most advanced and difficult of the ground-reference maneuvers. Because of the techniques involved, the
eights on pylons are unmatched for developing intuitive control of the airplane. Similar to eights around pylons except altitude is
varied to maintain a specific visual reference to the pivot points.
When performing eights on pylons, the pilot imagines there is a line parallel to the airplane's lateral axis that extends fro m the pilot’s
eyes to the pylon. Along this line, the airplane appears to pivot as it turns around the pylon. In other words, if a taut string extended
from the pilot's eyes to the pylon, the string would remain parallel to lateral axis as the airplane makes a turn around the pylon. The
goal of eights on pylons is to keep the line from the pilot's eyes to the pylon parallel to the lateral axis. The string should not be at an
angle to the lateral axis while the airplane flies around the pylon. [Figure 7- 10] When explaining eights on pylons, instructors
sometimes use the term “wingtip” to represent the proper visual reference line to the pylon. This interpretation is not corre ct. High-
wing, low-wing, swept-wing, and tapered-wing airplanes, as well as those with tandem or side- by-side seating, all present different
angles from the pilot’s eye to the wingtip. [Figure 7-11]
Figure 7-10. Eights on pylons.
The visual reference line, while not necessarily on the wingtip itself, may be positioned in relation to the wingtip (ahead, behind,
above, or below), and differs for each pilot and from each seat in the airplane. This is especially true in tandem (fore and aft) seat
airplanes. In side-by-side type airplanes, there is very little variation in the visual reference lines for different people, if those people
are seated with their eyes at approximately the same level. Therefore, in the correct performance of eights on pylons, as in other
maneuvers requiring a lateral reference, the pilot should use a visual reference line that, from eye level, parallels the lateral axis of the
airplane.
Figure 7-11. Line of sight.
The altitude that is appropriate for eights on pylons is called the “pivotal altitude” and is determined by the airplane's groundspeed. In
previous ground-track maneuvers, the airplane flies a prescribed path over the ground and the pilot attempts to maintain the track by
correcting for the wind. With eights on pylons, the pilot maintains lateral orientation to a specific spot on the ground. This develops
the pilot’s ability to maneuver the airplane accurately while dividing attention between the flightpath and the selected pylons on the
ground.
An explanation of the pivotal altitude is also essential. First, a good rule of thumb for estimating the pivotal altitude is to square the
groundspeed, then divide by 15 (if the groundspeed is in miles per hour) or divide by 11.3 (if the groundspeed is in knots), and then
add the mean sea level (MSL) altitude of the ground reference. The pivotal altitude is the altitude at which, for a given groundspeed,
the projection of the visual reference line to the pylon appears to pivot. Visually, a taut string, if extended from the pilot's eyes to the
pylon, would remain parallel to lateral axis as the airplane makes a turn around the pylon. [Figure 7-12] The pivotal altitude does not
vary with the angle of bank unless the bank is steep enough to affect the groundspeed.
Figure 7-12. Speed versus pivotal altitude.
Distance from the pylon affects the angle of bank. At any altitude above that pivotal altitude, the projected reference line appears to
move rearward in a circular path in relation to the pylon. Conversely, when the airplane is below the pivotal altitude, the projected
reference line appears to move forward in a circular path. [Figure 7-13] To demonstrate this, the pilot will fly at maneuvering speed
and at an altitude below the pivotal altitude, and then place the airplane in a medium-banked turn. The projected visual reference line
appears to move forward along the ground (pylon appears to move back) as the airplane turns. The pilot then executes a climb to an
altitude well above the pivotal altitude. When the airplane is again at maneuvering speed, it is placed in a medium-banked turn. At the
higher altitude, the projected visual reference line appears to move backward across the ground (pylon appears to move forward).
Figure 7-13. Effect of different altitudes on line of sight.
After demonstrating the maneuver at a high altitude, the pilot should reduce power and begin a descent at maneuvering speed in a
continuing medium-bank turn around the pylon. The apparent backward movement of the projected visual reference line with respect
to the pylon will slow down as altitude is lost and will eventually stop for an instant. If the pilot continues the descent below the
pivotal altitude, the projected visual reference line with respect to the pylon will begin to move forward.
The altitude at which the visual reference line ceases to move across the ground is the pivotal altitude. If the airplane descends below
the pivotal altitude, the pilot should increase power to maintain airspeed while regaining altitude to the point at which the projected
reference line moves neither backward nor forward but actually pivots on the pylon. In this way, the pilot can determine the pivotal
altitude of the airplane.
The pivotal altitude changes with variations in groundspeed. Since the headings throughout turns continuously vary from downwind
to upwind, the groundspeed constantly changes. This results in the proper pivotal altitude varying slightly throughout the turn. The
pilot should adjust for this by climbing or descending, as necessary, to hold the visual reference line on the pylons.
Selecting proper pylons is an important factor of successfully performing eights on pylons. They should be sufficiently prominent so
the pilot can view them when completing the turn around one pylon and heading for the next. They should also be adequately spaced
to provide time for planning the turns but not spaced so far apart that they cause unnecessary straight-and-level flight between the
pylons. The distance between the pylons should allow for the straight-and-level flight segment to last from 3 to 5 seconds. The
selected pylons should also be at the same elevation, since differences of over a few feet necessitate climbing or descending between
each turn. The pilot should select two pylons along a line that lies perpendicular to the direction of the wind.
The pilot should estimate the pivotal altitude during preflight planning. Weather reports and consultation with other pilots flying in
the area may provide both the wind direction and velocity. If the references are previously known (many flight instructors already
have these ground- based references selected), the sectional chart will provide the MSL of the references, the Pilot’s Operating
Handbook (POH) provides the range of maneuvering airspeeds (based on weight), and the wind direction and velocity can be
estimated to calculate the appropriate pivotal altitudes. The pilot should calculate the pivotal altitude for each position: upwind,
downwind, and crosswind.
The pilot should begin the eight on pylons maneuver by flying diagonally crosswind between the pylons to a point downwind fro m
the first pylon, so that the first turn can be made into the wind. As the airplane approaches a position where the pylon appears to be
just ahead of the wingtip, the pilot should begin the turn by lowering the upwind wing to the point where the visual reference line
aligns with the pylon. The reference line should appear to pivot on the pylon. As the airplane heads upwind, the groundspeed
decreases, which lowers the pivotal altitude. As a result, the pilot should descend to hold the visual reference line on the pylon. As the
turn progresses on the upwind side of the pylon, the wind becomes more of a crosswind. Since this maneuver does not require the turn
to be completed at a constant radius, the pilot does not need to apply drift correction to complete the turn.
If the visual reference line appears to move ahead of the pylon (pylon appears to move back), the pilot should increase altitude. If the
visual reference line appears to move behind the pylon (pylon appears to move ahead), the pilot should decrease altitude. Deflecting
the rudder to yaw the airplane and force the wing and reference line forward or backward to the pylon places the airplane in
uncoordinated flight, at low altitude, with steep bank angles and should not be attempted.
As the airplane turns toward a downwind heading, the pilot should rollout from the turn to allow the airplane to proceed diagonally to
a point tangent on the downwind side of the second pylon. The pilot should complete the rollout with the proper wind correction
angle to correct for wind drift, so that the airplane arrives at a point downwind from the second pylon that is equal in distance from
the pylon as the corresponding point was from the first pylon at the beginning of the maneuver.
At this point, the pilot should begin a turn in the opposite direction by lowering the upwind wing to the point where the visual
reference line aligns with the pylon. The pilot should then continue the turn the same way the corresponding turn was performed
around the first pylon but in the opposite direction.
With prompt correction, and a very fine control pressures, it is possible to hold the visual reference line directly on the pylon even in
strong winds. The pilot may make corrections for temporary variations, such as those caused by gusts or inattention, by reducing the
bank angle slightly to fly relatively straight to bring forward a lagging visual reference line or by increasing the bank angle
temporarily to turn back a visual reference line that has moved ahead. With practice, these corrections may become slight enough to
be barely noticeable. It is important to understand that variations in pylon position are according to the apparent movement of the
visual reference line. Attempting to correct pivotal altitude by the using the altimeter is ineffective.
Eights on pylons are performed at bank angles ranging from shallow to steep. [Figure 7-14] The pilot should understand that the
bank chosen does not alter the pivotal altitude. As proficiency is gained, the instructor should increase the complexity of the
maneuver by directing the learner to enter at a distance from the pylon that results in a specific bank angle at the steepest point in the
pylon turn.
Figure 7-14. Bank angle versus pivotal altitude.
Common Errors
The most common error in attempting to hold a pylon is incorrect use of the rudder. When the projection of the visual reference line
moves forward with respect to the pylon, many pilots tend to apply inside rudder pressure to yaw the wing backward. When the
reference line moves behind the pylon, pilots tend to apply outside rudder pressure to yaw the wing forward. The pilot should use the
rudder only for coordination.
Other common errors in the performance of eights on pylons are:
1. Failure to adequately clear the surrounding area for safety hazards, initially and throughout the maneuver.
2. Skidding or slipping in turns (whether trying to hold the pylon with rudder or not).
3. Excessive gain or loss of altitude.
4. Poor choice of pylons.
5. Not entering the pylon turns into the wind.
6. Failure to assume a heading when flying between pylons that will compensate sufficiently for drift.
7. Failure to time the bank so that the turn entry is completed with the pylon in position.
8. Abrupt control usage.
9. Inability to select pivotal altitude.
Chapter Summary
Ground reference maneuvers require planning and high levels of vigilance to ensure that the practice and performance of these
maneuvers are executed where the safety to groups of people, livestock, communities, and the pilot is not compromised. While
training to perform ground reference maneuvers, a pilot learns coordination, timing, and division of attention to maneuver th e
airplane accurately in reference to flight attitudes and specific ground references. After mastering ground reference maneuvers, the
pilot should be able to command the airplane to specific pitch, roll, and yaw attitudes, correct for the effects of wind drift, and control
the airplane’s orientation in relation to ground-based references. While safety is paramount in all aspects of flying, ground reference
maneuvers focus on mitigation of risk during low altitude flying. With these enhanced skills, the pilot also significantly improves their
competency in everyday flight maneuvers, such as straight-and-level, turns, climbs, and descents.