Pivotal Altitude – What? Why? How?
Wednesday, May 26th, 2010
Most pilots don’t think much about pivotal altitude. Commercial pilots remember it vaguely as an altitude you have to understand to be able to do on-pylon turns. CFIs need to be able to teach it to commercial applicants. What else is it good for? We never seem to read much about its possible applications. Here, then, are several good applications for pivotal altitude.
Pivotal altitude is a function of ground speed. You know that you are at pivotal altitude when, while in a coordinated turn, you can keep your wing tip off a point on the ground. When you fall below pivotal altitude the reference point moves behind the wing. The wing then covers the point you were circling on the ground. When you are making turns above pivotal altitude – where 99% of our flying is done – reference points on the ground appear to move ahead of the wing. The latter appearance is so familiar to us that we aren’t generally aware of it. Commercially rated pilots are familiar with pivotal altitude from maneuvers such as on-pylon 8s. Unfortunately, most of us were never told why an understanding of pivotal altitude was important other than for passing our commercial practical test.
