Performance Requirements for Exploiting Microlift
Some people may question the adjective "high performance" ... but when your ultimate goal is a sink rate of 1 fps or 60 fpm, achieving a sink rate of 100 fpm is indeed high performance. But sink rate alone is not the answer. Many glass ships with very high L/D ratios achieve a low sink rate ... but at a relatively high speed. The high speed of glass ships makes it difficult to exploit the inner core of narrow thermals on weak days. According to papers presented by Gary Osoba, your sailplane must meet several criteria to operate in the regime of microlift and microthreads of lift:
| Spec: | Required for exploiting microlift ... mostly from Gary Osoba |
| 100 fpm | Very low sink rate |
| 25 mph | Very low speed at above sink rate |
| Extremely small thermalling circle diameter (directly related to the speed squared ... v2) | |
| 26:1 | A decent glide ratio at a respectable speed ... here the Carbon Dragon is weak. |
| 20 feet | Altitude loss during a 360 degree turn |
| docile stall entry and very rapid recovery ... Steve Arndt |
Some people are skeptical about the loss per turn, but on a very overcast day with no lift, I have seen Osoba complete four 360 degree turns while finishing a full pattern and landing at Elmira ... after a 200' autotow launch! ... where I drove the tow vehicle.