Pivotal Altitude
Eights on pylons. Pivotal altitude follows groundspeed, so in any wind it is a range, not a number — lowest upwind, highest downwind.
At 90 kt true airspeed in 15 kt of wind, you are pivoting between 498 and 976 ft AGL — 478 ft of climb and descent every time around.
Click − or + to nudge; hold for a coarse jump. Elevation steps 100/1,000 ft above sea level and 1/10 ft below it.
Ground elevation is 0, so MSL and AGL are the same number. Set it to the terrain elevation at the pylons before you fly to the MSL column.
Turning the wind direction rotates this circle — it moves where the high and low fall, not what they are. Only wind speed changes the numbers. Watch the bars beside this swing round as you change it.
Heading, not track — the nose visits every heading in the turn and the drift is not corrected.
The upwind side falls to 498 ft AGL, below the 500 ft of 91.119(c). Legal only over open water or a sparsely populated area, and never within 500 ft of a person, vessel, vehicle or structure — which constrains the pylons you pick.
Pylon slides ahead of your wingtip reference — too high, descend. Slides behind — too low, climb.
Altitude is the control. Yawing to hold the pylon is uncoordinated, does not work, and is explicitly disqualifying (CA.V.E.S8).
Not a ground-reference maneuver. You are holding a sight line, not a ground track — understand the wind's effect, do not correct to a track.
Bank is an outcome, and varies around each pylon — but never past 40° (CA.V.E.S5).
The wingtip reference is yours: it depends on your seat height, so establish it and do not move the seat.
What pivotal altitude actually is
The altitude at which the reference line from your eye to a point on the ground appears to pivot on that point — no forward or backward drift along the wingtip. Fly above it and the pylon appears to move rearward; fly below it and it creeps forward.
It falls out of geometry, not aerodynamics, which is why it depends on groundspeed and nothing else — not weight, not bank angle, not aircraft type. Roughly, pivotal altitude in feet is groundspeed in knots squared, divided by 11.3.
Why it changes as you come round
Because it depends on groundspeed, and groundspeed changes continuously through a turn in any wind. Downwind you are faster over the ground, so pivotal altitude is higher; upwind you are slower and it is lower.
That is the whole difficulty of eights on pylons. You are not holding an altitude — you are flying a shallow climb and descent, timed so the pylon stays pinned. The spread between the upwind and downwind figures is how much vertical travel the wind is asking of you, and it is the number worth knowing before you go.
The mistake almost everyone makes first
Using indicated or true airspeed instead of groundspeed. The formula takes groundspeed, full stop. If the aircraft shows you groundspeed directly, use that. If you are working from indicated airspeed you have to correct for density altitude and then for wind, and getting either wrong moves the answer enough to make the pylon drift — which is usually blamed on the flying rather than on the number.
What this does not do
It gives you a planning figure, not a target to chase in the air. Pylons are flown by looking outside at the reference, not by staring at the altimeter. Use the numbers to know roughly where you should be and how much the wind will move you, then fly the sight picture. And check the range against the maneuvering altitude your aircraft and the terrain actually allow.