When it comes to pure mastery of an aircraft, eights on pylons stands out for many commercial pilot applicants. The maneuver must be flown precisely under conditions that are changing constantly.
When flying eights on pylons, the pilot selects two objects (pylons) aligned 90 degrees to the direction of the wind, and flies a figure eight between them, keeping the lateral axis of the airplane directly aligned on those points. Altitude and airspeed will vary as the pilot works to keep the pylon where it needs to be, but whatever power setting is used should remain unchanged.
Breaking down the maneuver into three stages, the pilot starts by calculating the pivotal altitude that will be used to fly the maneuver. This altitude is calculated in feet above ground level. Unfortunately, it involves math: Take the groundspeed, square it, and then divide by 11.3 if using knots. So, for a 100-knot groundspeed, 100 squared is 10,000, divided by 11.3, which is 885 feet. That’s fairly low to the ground. (Add local elevation to the equation for your mean sea level altitude.) If you don’t wish to do mental math while flying, estimate this altitude beforehand and adjust based on the sight picture once you start the maneuver.
Pivotal altitude is affected by variations in groundspeed, so your altitude will change constantly throughout the maneuver, increasing with a tailwind and decreasing with a headwind.
Next, pick your pylons. They can’t be too close together or too far apart. For example, if your choice of pylons has you flying more than five seconds straight and level between them, they’re too widely spaced to work. Pick a pylon, circle it, roll out, count to three, and that’s the distance you should strive for when choosing a second pylon. Alternatively, pick two objects that are about a mile apart. Choosing two pylons that lie on opposites of a road or other straight line will help you keep both objects in sight, plus give you a reference point in the middle. Since you’ll be flying relatively low to the ground, it’s prudent to keep a suitable spot for an emergency landing in the back of your mind.Finally, fly the maneuver. Enter downwind, and try to visualize a tether from the lateral axis of your airplane to the pylon. Circle the pylon, adjusting your groundspeed and altitude to keep the pylon off the wing tip. If the wing tip moves behind the pylon, you are flying higher than the pivotal altitude and you must descend. Similarly, if the wing tip moves ahead of the pylon, you are flying below pivotal altitude and will need to climb. Keep bank angles below 40 degrees. And no skidding or flying non-coordinated as you circle your pylons.