Nibble Falcon's Shift Thermaling Circles Often

This is a very interesting article which relates to soaring in some interesting ways.  Like the Peregrine, soaring pilots need to constantly shift their circles as pulses or bubbles of stronger lift work their way up through the main column.  Pilots often wonder why someone several hundred feet above seem to be climbing away from them.  “What’s wrong with me?”  Doubt creeps in.  I think, more times than not, the other glider is simply riding a stronger pulse of surging air in that thermal; therefore, no reason for self doubt.

The article points out:

Glider pilots already have a simple set of rules developed by the long distance glider pilot Helmut Reichmann (who died in a mid-air collision in 1992). Pilots apply these so-called Reichmann rules when they are climbing in a spiral due to a thermal. The rules are these:
1. If the climb improves, widen the spiral by decreasing the banking angle.
2. If the climb deteriorates, tighten the spiral by increasing the banking angle.
3. And if the climb remains constant, keep the banking angle constant.

This works reasonably well but has important limitations, particularly when there is thermal noise (ie turbulence) in the atmosphere. Turbulence can fool fliers into thinking they’re in a thermal when in fact they’re not; and vice versa, fooling them into thinking they’re not in a thermal when they are.

Read the full article