IFR in a glider means I Follow Roads, right?
Well it can mean that too, but not all roads lead to good lift. What works nearly every time is following Raptors!
And just as most roads lead in two directions, birds in straight flight offer a similar choice. On average, those who are low and flapping are apt to be going toward lift, but when high and gliding, might be pointed directly away from it… Though hardly a stroke of genius, that could be a pivotal distinction. And the exact meaning of low and high, BTW, is up to you.
Many kinds of birds mark lift in different ways, such as geese, ducks, and pelicans. Even little tweety birds sometimes soar high aloft, still flapping their wings as they gobble insects carried up by thermals. (Them you may not see, however, until you’ve already found the lift.)
Ravens are the smartest creatures in the sky and master aeronauts in every phase, but their curiosity and deviousness make them unpredictable. They can mark lift brilliantly, yet don’t always circle in it. When you see three or four ravens just goofing off dogfight style, the secret is they’re probably marking lift then, too! Alas, they tend to flee when we approach, so whatever they’re up to, we should note where they were at first, and go there as they fly away…
Vultures we often see from the ground, singly or in large groups, but only rarely have I had the fortune to soar with one in a thermal. Although technically categorized as raptors, the game they hunt is no longer alive. Their trick is not catching prey with stealth or quickness, it’s detecting where remains lie, perfectly still, fading into the landscape. Hence their specialty of flying low and very slow, conserving energy in lieu of accumulating more. Efficiency is not a one-sided coin, after all.
Twice, three years apart, I watched a vulture circle slowly down over the same paved runway, waiting for a thermal to form there. Same individual? Doesn’t matter. Point is, in each case its actions were identical, and so was the result. The bird hung motionless in a shallow bank on the verge of stall, wings locked at the root, exerting no apparent muscular energy except a constant fugue of blue notes with its tail feathers. It finally bottomed out not much above fifty feet as the bubble marshaled energy — and no surprise, when a teensy dust devil sprang up, the vulture’s circle was already centered on it.
Throughout all that slow descent, then several circles of sketchy zero and many more of incremental climb, the maestro never moved a wing! Only several hundred feet up did it finally flap a couple times, not to get higher, but to generate speed for a steeper bank into the thermal’s accelerating core. Simultaneous with that, the little whirlygust gave a hushed aeroacoustic growl, pulled up its invisible trap door and left the earth for good.
Ten minutes later the maestro had specked out and gone, both times the same, three years apart. I’ll never prove that having witnessed those twin tours de force has somehow enhanced my own buoyancy in a slew of lowdown dig outs — nor can you prove it hasn’t. One of us knows the truth.
Big picture though, it’s hawks and eagles who serve as our premier soaring tutors. They fly like saintly warlocks, fierce yet dispassionate, low and very high, slow and very fast. What’s more, they have the nerve to hold position when we intrude. From any remote distance, just head straight at them, they won’t care. Not much reason to worry about ever hitting one, they’re way too quick for that. They’ll either ignore you completely or stare back in defiance, challenging you to stay with them in the very best lift.
It’s simple stuff, in principle. Centering your turn around a bird’s smaller one – the same direction of course – also makes it easier to observe. And here’s where this gets interesting. You’ll see they seldom fly many consecutive circles without some change in attitude… or direction. Raptors don’t need rules of the road; results are all that matter. Consider their every move as optimized to extract more energy from that particular situation, and do what you can to follow their lead. (Plus, if you’ve got the brain space, try to visualize more of what their singular fight paths imply about surrounding airflow.)
Wherever right of way does become an issue, just do what wise glider pilots always should, and give it up! Any bird will shy away at the last instant – if it sees you – but when you fear it may not and contact seems imminent, one rule always applies. Their first defensive strategy is to dive, so never fly directly under one, and when they’re right at eye level, don’t lower your wing it, raise it. More than once, I’ve gladly pulled my craft into a stall to assure safe passage for both vessels. Shrewd bargain if you think about it.
All these feathered exemplars will outclimb us with embarrassing quickness, and that’s okay. In the whole world, there’s no better opportunity to study how they do it and find ways to emulate perfection. We have few sure things in soaring, but IFR comes close.