Objective:
To develop the student's ability to maneuver the airplane in close proximity to the ground and to keep a point along a specific reference through changes in altitude as a response to changes in ground speed while dividing attention inside and outside the airplane.
Elements:
- Visually clear the area and determine the wind direction and speed.
- Select a straight ground reference line or road with two points (pylons) that are perpendicular to the direction of the wind with suitable emergency landing areas.
- Pylons must be far enough apart to provide 3-5 seconds of straight and level flight between turns.
- Determine approximate ground speed and calculate pivotal altitude. KTAS2/11.3
- Enter maneuver on 45° to downwind at the determined pivotal altitude and note heading.
- Abeam the selected pylon, begin a maximum bank turn (30°-40°) and pivot around pylon maintaining the reference point (wingtip) on the pylon. See diagrams color or bw.
- Pylon forward - Controls Forward, Reduce Bank
- Pylon rearward - Controls Back, Increase Bank
- After completing turn around first pylon, roll wings level and fly between selected pylons at 45° angle.
- Abeam the second pylon, begin turn in opposite direction and repeat step 6.
- After completing the turn around second pylon, depart the maneuver on entry heading.
Common Errors:
- Failure to clear the area of other traffic.
- Selecting reference points without a suitable emergency landing area within gliding distance.
- Improper entry of the maneuver relative to the wind.
- Excessive gain or loss of altitude.
- Failure to maintain reference line (Possibly due to misunderstanding of pivotal altitude).
- Improper selection of points or pylons.
- Poor planning, orientation, or division of attention inside and outside the aircraft.
- Uncoordinated flight control application.
References:
- FAA Commercial Pilot PTS p. 1-25
- Pilot's Handbook of Aeronautical Knowledge, pp 3-17 (Aerodynamic Forces During Maneuvers)
- Airplane Flying Handbook, pp 6-12 – 6-16
Notes:
- Neither constant altitude nor radius are required for this maneuver.
- Pivotal Altitude: The altitude at which, for a given ground speed, the line of sight will appear to pivot on the chosen point. Does not vary with angle of bank unless bank affects ground speed.
- Distance from pylon effects angle of bank.
- If aircraft is HIGH, pylon will move forward of the "wingtip" and aircraft must DECEND.
- If aircraft is LOW, pylon will fall behind the "wingtip" and aircraft must CLIMB.
- Proper selection of pylons is essential for executing this maneuver correctly.
- After establishing aprox. pivotal alt. over fly area on a X-wind with wind off the right wing.
- Select points (pylons) to the left of the aircraft that are about 8-12 seconds apart.
- After passing second pylon continue outbound for 10sec and make a right teardrop back.
- Enter the maneuver 45° crosswind to downwind and pass between the two points.
- As reference line approaches pylon, begin the turn to the left while placing "wingtip" on pylon.
- As the turn progresses toward upwind, ground speed decreases and therefore so does the pivotal altitude. The aircraft must therefore descend to hold the pylon with ref. point "wingtip".
- As the aircraft turns through the upwind side of the pylon to the downwind side, ground speed will increase and therefore require a higher pivotal altitude. The aircraft may have to climb to hold the pylon and reference point even.
- As the aircraft approaches a downwind heading, roll out to make a 45° diagonal transition flying 3-5sec between the pylons to the downwind side of the second pylon.
- Repeat procedure in opposite direction for second pylon.
|