When entering a thermal not already marked by a circling glider, which way should you turn? Toward it of course, if you know which side it’s on. But that’s not always certain at first, so what other rationales might there be?
Everyone agrees on flying our circles against any lateral rotation, if it exists, but that’s seldom apparent either. One old timer said that since most dust devils in the northern hemisphere rotate counterclockwise due to Coreolis effect, he always turned clockwise, i.e. to the right. Okay, but even if there is lateral rotation, it’s typically very minor (except in dust devils) and will approach zero not far above ground level anyway… Another pilot always turned left regardless of any other considerations, because that’s required for competition where he came from in Europe. Other than solving the problem of folks occasionally circling opposite directions, these strategies seem more trouble than they’re worth. And there are others that confuse the issue even further.
All other factors being equal, I nearly always make that first turn into the prevailing wind, left or right. My rationale: every thermal drifts in the wind as it rises, so an infrared snapshot would show the thermal leaning downwind (visualize this schematically and think it through so you really understand it). Because air rising toward you comes from the windward direction, if you turn downwind and don’t find lift you descend through the sinking air beneath the thermal while it continues to rise, and you’ll need to fly an upwind leg to relocate that thermal at some lower point further away. But if you turn into the wind and away from lift you’ll be descending into space from which lower, newer pulses continue to rise, and simply continuing your circle will probably bring you back into lift with minimal loss of altitude or time.
It’s a big sky and which way you turn for any particular thermal is, usually, a small stakes gamble. There’s plenty of room up there for you to devise your own strategy. Meanwhile, in any possible scenario from aborted takeoff to crash landing, if you’re unsure which way to turn, the best default is into the wind.
We can expect the coming week to bring pleasantly cooler days and at least some of the marking clouds that were missing through most of September. Thermal activity is declining now (with still a long ways to go!), and if the southerly wind picks up we can expect a puncher’s chance of WAVE for the weekend.
Some pilots begin their landing pattern far higher than the normal altitude, or from some unusual place, often from mere sloppiness. We generally discourage that for several reasons.
First, here at Crystal more than half our flights are for training, whether with an instructor or solo, and it’s tough to develop solid technique for predictable landings while starting from a different point each time. Those who lack inexperience or currency need practice, and dismissing standard procedure denies that purpose altogether.
Also, other pilots may be nearby, lower but still above pattern height, still trying to stay aloft (I’ve been right there a hundred times). By entering too soon you could oblige
me them to give up and land first, only to pay for another tow. Perhaps someone is below you in a blind spot – theirs and/or yours – intending to land before you do. They may never see you and unknowingly cut you off. Or others may see you but not believe you’re really in the pattern, and so commit to their own approach…
You think we’re overstating this? True story: A student once entered downwind 300 feet higher than standard, and while he was arguing that the difference didn’t matter, not one, but two other gliders passed under us at the proper height, supposing we’d follow them in a minute or two later. Yes, that happened.
If you happen to arrive lower than standard pattern entry height, however, flying a ‘proper’ pattern would only squander precious energy and lengthen the period of increased hazard. Instead (being careful not to interrupt ordinary traffic!) fly directly to the point where you can intercept standard procedure as high and as soon as possible — even if it means a nice crisp COORDINATED turn to final at 100 feet. The objective, after all, is to make a safe landing in a safe place. Nothing else matters.
Practicing the straight-and-narrow of standard landing patterns leaves all that other air space available for dire improvisation in genuine emergencies — for which every self-respecting aviator should develop the flexibility to adapt when necessary. We do encourage rated pilots to practice unusual approaches when appropriate, but only with communication beforehand.
Earlier, I distributed some nonsense about September being a good time to look for lots of beautiful cloudscapes… Well now three weeks into the month, we’ve hardly seen a single cloud so far. While this coming weekend does promise improving thermal conditions, cloud base will be so high, if we do see even a teensy cumulus it’ll be marking some very good (and tall) lift. And from here on our days will be shorter than our nights, so get ‘em while they last!