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Frank Whiteley wrote:
White Storks. Although they can only fly about 30 miles on the flap, .... Impressive glide also. But as research has shown, they have no clue of the McCready theory: http://infonet.vogelwarte.ch/upload/00544921.pdf |
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On Nov 15, 9:08*am, John Smith wrote:
Frank Whiteley wrote: White Storks. *Although they can only fly about 30 miles on the flap, ... Impressive glide also. But as research has shown, they have no clue of the McCready theory:http://infonet.vogelwarte.ch/upload/00544921.pdf Neat paper. |
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On Nov 15, 4:59*am, Scott Alexander
wrote: So in a recent conversation with a greatly experienced soaring pilot, I was told that Buzzard's have terrible thermaling skills. I tend to agree with this as it sure seems Buzzards don't get into the core and stay there. The lesson learned was don't let Turkey Buzzard show you where the core is, just let them lead you to the thermal. I thought it would be interesting to ask you good people if anyone has any knowledge on these issues. *Does anyone know which broad winged birds have better or worse centering techniques that you can use to your advantage? SA I've been writing some short articles on birds and soaring. I'll attach some exerpts from one here. In Arizona and Coloorado the big wing birds I work with most are Red Tail Hawks. But, when looking for the best cores the little Swifts are THE best indicators... but you have to look closely to notice them. Swifts are a family (Apodidae) of small, highly aerial birds, flying almost constantly except when at the nest or roosting at night. As using rising air helps conserve their energy, these little guys are real pros at working thermals, and they tend to find the best thermals wherever they fly. They also have impeccable eyesight (about 10X human eyesight), allowing them to see small insects in the air. Amongst the fastest flyers in the animal kingdom, the common swift (Apus apus) can cruise at 12 to 30 mph and is capable of 130 mph for short bursts. Swifts not only can fly fast, they are incredibly aerobatic, often changing directions almost instantly, which helps in their quest for dinner in thermals. Back when I was flying hang gliders cross-country, we saw them often (commonly above 16,000’), and when we did, we knew we were in the best part of one of the best thermals of the day. Sitting under the hang glider, fully exposed to the elements, I had a “front-row seat” to watch swifts dart around me in good thermals. It was not unusual to see them zip in between my wings and flying wires, often within a foot or so of me. Incredible flying accuracy. Little wonder one of the première aerobatic gliders is aptly named the SWIFT! Powerful thermals vacuum insects from the surface and propel them skyward, and swifts have an uncanny knack for spotting these swirling aerial food bazaars, utilizing them for high altitude feasting. In the spring of 2009 I was flying with a friend, Ted Grussing, in his Lambada motorglider on a good soaring day, and we worked some pretty nice thermals going to and from the Grand Canyon. It was one of those days when about ¾ of the clouds were duds, as far as good thermals were concerned. On the way back, we glided over to the best looking cloud of the day, and rode the elevator up. Seeing a swift dart by as I was making the 3rd 360, I immediately turned to core what he was in. Bingo! Our 12 kt average leaped to 17 kts in the tight core. Yahoo! Crank & bank! The good looking cloud had attracted us, but the swifts helped me find the best part of the core. The last we saw of them was when we were pulling out at 17,500’. Those little guys obviously aren’t concerned about class A airspace…. Bob T. 19 |
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On Nov 15, 3:59*am, Scott Alexander
wrote: So in a recent conversation with a greatly experienced soaring pilot, I was told that Buzzard's have terrible thermaling skills. I tend to agree with this as it sure seems Buzzards don't get into the core and stay there. The lesson learned was don't let Turkey Buzzard show you where the core is, just let them lead you to the thermal. I thought it would be interesting to ask you good people if anyone has any knowledge on these issues. *Does anyone know which broad winged birds have better or worse centering techniques that you can use to your advantage? SA Red Tailed Hawks and their brethren seem to be the best at thermalling, they have helped me numerous times. Turkey Vultures are great for following, IF they are going up, once they hit the thermal all hell breaks loose and they thermal in very unruly groups. They seem to be really good at finding micro-lift threads. Swallows and Swifts don't seem to really "thermal", I suspect they just get sucked straight up while chasing bugs............but I've seen these guys many times at cloudbase bombing around like fighter planes. Soaring would be a lonely place without our raptor friends! Brad |
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On Nov 15, 5:59*am, Scott Alexander
wrote: So in a recent conversation with a greatly experienced soaring pilot, I was told that Buzzard's have terrible thermaling skills. I tend to agree with this as it sure seems Buzzards don't get into the core and stay there. The lesson learned was don't let Turkey Buzzard show you where the core is, just let them lead you to the thermal. I thought it would be interesting to ask you good people if anyone has any knowledge on these issues. *Does anyone know which broad winged birds have better or worse centering techniques that you can use to your advantage? SA An excellent soaring bird has not been mentioned: the Sandhill Crane. Although I have never soared with them, I watch hundreds of them per flock migrating from and to N. Wisconsin and Canada over our Western Chicago suburb each fall and spring. They wait for the right wind direction and instability (which there is not much of especially in fall) and climb/run as we do without batting a wing. They go into formation while running but the flock is without structure while in a thermal. They are magnificent large birds and their cries are very distinct. They are the first reliable sign in early to mid March that the Winter is on the way out and their sights and sounds are very much welcomed. Herb, J7 |
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On Nov 15, 8:48*am, Herbert kilian wrote:
An excellent soaring bird has not been mentioned: the Sandhill Crane. Very true, Herbert! In Central/Eastern Washington State there's a big Sandhill Crane migration every spring... We can hear the huge flocks on the ground as they pass over our gliderport at several thousand feet - loud conversationalists, they are! I've never shared a thermal with one, but I've flown near them and noticed they have an uncanny knack for finding shear-lines and streets. Someday I'll figure out how to take advantage of those myself... :-P --Noel |
#7
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In article
, Scott Alexander wrote: So in a recent conversation with a greatly experienced soaring pilot, I was told that Buzzard's have terrible thermaling skills. I tend to agree with this as it sure seems Buzzards don't get into the core and stay there. The lesson learned was don't let Turkey Buzzard show you where the core is, just let them lead you to the thermal. I thought it would be interesting to ask you good people if anyone has any knowledge on these issues. Does anyone know which broad winged birds have better or worse centering techniques that you can use to your advantage? SA Others have mentioned swifts. Here in the eastern U.S. they seem to me to be the best tell-tale of a superior thermal. One bird that has not been mentioned, but is a great indicator of a good thermal, is the Anhinga. They are also known as the snake bird or water turkey. In flight, they look like an arrow with high aspect ratio wings attached. They are a water bird so are usually around the low, wet places we sailplane pilots dread. I have only found them thermalling in good lift. Look for them the next time a sadistic CD puts your course line right down a river valley or across a swamp or lake. |
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On 15 Lis, 12:59, Scott Alexander
wrote: I thought it would be interesting to ask you good people if anyone has any knowledge on these issues. *Does anyone know which broad winged birds have better or worse centering techniques that you can use to your advantage? In Poland Hawks are very good thermal indicators and they're quite common. Most of the time I find better lift when I move closer to them. From what I've heard Eagles are even better but they're very rare here and I haven't had a pleasure of meeting one. I would avoid White Storks, especially on weak days - they're great soarers but they're low wing loading let's them use thermals that would just reduce glider's descent rate a bit. -- Wiktor |
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A few years ago I was sharing a thermal with three storks at 1800 m
and it seemed that one of them was very young and had not mastered its thermaling technique quite yet. It would make sudden corrections and flap a few times while the other two calmly circled and waited for it to catch up. When they got together they took off in tight formation. I was headed in about the same direction so I was able to watch them for several miles and I was amazed by their glide speed which appeared to be close to 80 km/h. Truly incredible birds.. I don´t know if they soar for fun but it looked like they were having a great time. Regards, Juan Carlos |
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On Nov 16, 4:03*am, JC wrote:
A few years ago I was sharing a thermal with three storks at 1800 m and it seemed that one of them was very young and had not mastered its thermaling technique quite yet. It would make sudden corrections and flap a few times while the other two calmly circled and waited for it to catch up. When they got together they took off in tight formation. I was headed in about the same direction so I was able to watch them for several miles and I was amazed by their glide speed which appeared to be close to 80 km/h. Truly incredible birds.. I don´t know if they soar for fun but it looked like they were having a great time. Regards, Juan Carlos a few years ago I shared a thermal with a whole flock of Geese. They were in a typical V formation then they hit the thermal, turned into the wind and just hung there, they did break formation a little. I circled around them as we all climbed together. It appeared they just sort of took a rest break in the air, hovering in one spot. After a while they turned back North and re-formed the V formation but seveal hundred feet higher. It was really cool to watch. Dan WO |
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