Eights-on Pylons

Eights-on Pylons

• Not to be confused with • Eights around pylons • Eights across a road • Eights along a road

Objective

• Exhibit your knowledge of the elements related to eights-on pylons including the relationship of groundspeed change to the performance of the maneuver

Objective

–Involves flying the aircraft in circular paths, alternating left and right in the form of a figure”8” around two selected points or pylons –Altitude and airspeed vary such that a line parallel to the lateral axis extending from your eye to appears to pivot on each pylon

Objective

–No attempt is made to maintain a uniform distance from the pylon –Use a sighting reference line parallel to the lateral axis of the plane. High and low wing airplanes, swept wing, tandem seating will all present different angles from the eye to the wingtip

Objective

–It may be ahead, behind, above or below the wingtip • Groundspeed effects the performance of the maneuver

Objective

–At a given groundspeed there is an associated altitude at which the airplane will appear to pivot about the point and is called the pivotal altitude –The higher the groundspeed the higher the pivotal altitude

Objective

• Pivotal altitude is not a function of angle of bank –In calm air with groundspeed constant the pivotal altitude around the pylon would be the same

Objective

–If you started the maneuver close to the pylon the angle of bank would be higher but the pivotal altitude would be the same • The speed of the wind will affect the altitude changes to maintain the pivotal altitude

Objective

–In strong wind, altitude changes will be greater e.g. 100 to 200 feet –In light wind, altitude changes will be smaller e.g. 50 to 100 feet –Wind calm means no change to pivotal altitude

Determine the Pivotal Altitude • At an altitude above the pivotal altitude, your reference line will appear to move rearward in relation to the pylon

Determine the Pivotal Altitude • At an altitude below the pivotal altitude, your reference line will appear to move forward in relation to the pylon

Determine the Pivotal Altitude • To determine the pivotal altitude fly at an altitude well above the pivotal altitude then reduce power and descend at cruise airspeed in a medium bank turn.

Determine the Pivotal Altitude • The reference line will move back until the pivotal altitude is reached. If you continue to descend the reference line will move forward • You can estimate the pivotal altitude by using the following formula

Determine the Pivotal Altitude (Groundspeed in knots) 2 = 11.3

Pivotal Altitude 100 2 11.3

= 885

Determine the Pivotal Altitude 130 2 11.3

= 1495

Determine the Pivotal Altitude If you are using an airplane with an airspeed indicator marked in Miles per Hour use 15 for the denominator (100 mph) 2 15 = 666

Select Pylons

• Consider force landing areas and select pylons that will allow you to fly straight and level for 3 to 5 seconds between pylons • Pylons must be perpendicular to the wind

Select Pylons

• No closer than 1/2 mile apart • Emergency landing areas • Perform clearing turns and look for towers and other obstacles

Configuration & Airspeed

• Use the specified configuration in the POH • For the Bonanza use training cruise of 120 knots using 18” MP and 2300 RPM

Configuration & Airspeed

• Minimum altitude would be 1274 ft AGL if no wind, probably 1500 ft • Enter the maneuver moving diagonally crosswind between the pylons to a point downwind of the pylon and make the first turn into the wind

Configuration & Airspeed

• As you approach the pylon, it will be slightly ahead of the reference line, start the turn to keep the line of sight reference on the pylon

Perform the Maneuver

• Apply necessary corrections to line of sight reference remains on the pylon with minimum longitudinal movement • As you change headings the groundspeed will change causing the pivotal altitude to change

Perform the Maneuver

• As you turn into the wind the groundspeed decreases causing the pivotal altitude to decrease causing you to descend to maintain the pivotal altitude

Perform the Maneuver

• As you progress upwind of the pylon the crosswind will push you closer to the pylon • You do not have to maintain a constant distance from the pylon this is not Turns About a Point

Perform the Maneuver

• If you drift closer to the pylon increase your angle of bank • If the reference line moves ahead of the pylon you should increase your altitude

Perform the Maneuver

• If the reference line moves behind the pylon you should decrease altitude

Orientation and Planning

• Remain oriented on the location of the pylons and the direction of the wind • Plan ahead • Divide your attention between coordinated airplane control and outside visual reference

Orientation and Planning

• Watch out for other traffic

Apply Wind Correction

• As you turn toward the downwind heading you must rollout with sufficient crab angle to correct for wind drift • You must arrive downwind of the second pylon the same distance as you were from the first pylon

Use Pivotal Altitude

• Hold the pylon by climbing or descending to maintain the pivotal altitude • Use rudder to maintain coordinated turns

Use Pivotal Altitude

• Do not use rudder to force the reference line forward or backward to the pylon

Common Errors

• Faulty Entry technique –Poor planning –Not being at pivotal altitude –Rolling into a bank too soon • Poor Planning, Orientation and Division of Attention

Common Errors

–Lack of anticipation of changes in groundspeed –Poor pylon selection –Poor division of attention. Uncoordinated flight control applications and not looking out for other traffic

Common Errors

• Uncoordinated flight control application • Use of improper line of sight reference • Application of rudder alone to maintain line of sight on pylon – Most Common Error

Common Errors

–Do not Yaw the wing backward with rudder if the reference line is ahead of the pylon • Improper timing of turn entries and rollouts –Usually do to poor planning

Common Errors

–Rollout needs to be timed to allow the airplane to proceed diagonally to a point downwind of the second pylon

Common Errors

• Improper correction for wind between pylons • Selection of pylons where there is no suitable force landing area within gliding distance • Large pitch and airspeed changes