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Pivotal Altitude Calculator

The altitude where the pylon stands still.

In eights on pylons there's one altitude where your wingtip reference line stays pinned to the pylon — the pivotal altitude. It depends only on groundspeed: GS² ÷ 11.3. Enter your groundspeed to get it in feet AGL (and MSL over your terrain), then read why it keeps changing as the wind swings your groundspeed around the turn.

Pivotal Altitude Calculator

Groundspeed, not airspeed — that's the whole trick of the maneuver. Add your terrain elevation to see the MSL altitude to fly.

Educational estimates only — not for flight planning or dispatch. Fly the maneuver per the Airplane Flying Handbook and your instructor.

kt
115 mph
ft
Pivotal Altitude
885 ft AGL
Altitude to Fly
885 ft MSL

How pivotal altitude works

Pivotal altitude (ft AGL) = groundspeed² ÷ 11.3 with groundspeed in knots (÷ 15 for mph). At 100 kt that's 885 ft AGL; at 110 kt, 1,071 ft. The physics: at exactly this height, your angular rate around the pylon matches the rate the pylon's bearing changes, so the lateral reference line appears frozen on it.

GroundspeedPivotal altitude
90 kt717 ft AGL
100 kt885 ft AGL
110 kt1,071 ft AGL
120 kt1,274 ft AGL
130 kt1,496 ft AGL

Why you're always climbing or descending: the wind changes your groundspeed continuously around the pylon — fastest on the downwind side, slowest upwind. Since pivotal altitude tracks GS², you climb as you accelerate through the downwind side and descend as you slow on the upwind side. The visual cue closes the loop: if the pylon appears to move ahead of your wingtip reference line, you're below the pivotal altitude for your current groundspeed — climb back to it. If the pylon appears to fall behind the line, you're above it — descend.

Commercial-checkride staple: examiners love asking for the pivotal altitude at your entry groundspeed. Compute a table for your typical maneuvering speeds before the ride — and remember your entry altitude also has to respect minimum-safe-altitude rules over the terrain. High-elevation practice areas change your density altitude and the true airspeed behind any groundspeed — cross-check with the TAS calculator on hot days.

Frequently asked questions

How do you calculate pivotal altitude?

Square the groundspeed in knots and divide by 11.3 to get feet AGL (with mph, divide by 15). At 100 kt groundspeed: 100² ÷ 11.3 ≈ 885 ft AGL. Add terrain elevation for the MSL altitude to fly.

Why does pivotal altitude change during eights on pylons?

Because it depends on groundspeed squared, and wind changes your groundspeed around each pylon — highest downwind, lowest upwind. You continuously descend into the upwind side and climb on the downwind side to stay on the pivotal altitude.

What do I do if the pylon moves ahead of my reference line?

The pylon appearing to move ahead means you are below the pivotal altitude for your current groundspeed — climb to catch it. If the pylon drifts behind the line, you are above pivotal altitude — descend. It's the same logic as the wind correction: groundspeed builds on the downwind side, raising the pivotal altitude, so the pylon starts creeping ahead and you climb.

Does bank angle or airspeed affect pivotal altitude?

No — only groundspeed. Bank angle determines how far from the pylon you fly (steeper bank, closer pylon), and indicated airspeed matters only through the groundspeed it produces with the wind. That's what makes the maneuver such a good test of wind awareness.

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