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#11
July 24th 03, 06:38 PM
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Trust me, if anyone ever broke that record the SR would have easily
re-established a higher record . . . The original record "upper limit" was set "low" to mask the true capabilities of the aircraft. Steve Swartz "RobbelothE" wrote in message ... I'm still amazed at the New York to London record set September 1, 1974: 1 hour 54 minutes and 56.4 seconds with an average speed of 1,807 statute mph over the 3,461 statute mile distance (and that INCLUDES slowing down for a refueling over the Atlantic)!!!!!!! Ed "Those who have long enjoyed such privileges as we enjoy forget in time that men have died to win them." Franklin D. Roosevelt, Address for Bill of Rights Day 15 Dec 1941 (Delete text after dot com for e-mail reply.) 
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#12
July 24th 03, 07:59 PM
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Trust me, if anyone ever broke that record the SR would have easily re-established a higher record . . . The original record "upper limit" was set "low" to mask the true capabilities of the aircraft. Steve Swartz With all the radar and stuff like that there why are the capabilities of the SR-71 still classified. I'm sure the bad guys already know. I'd really like to know how high and how fast it realy was. Dan, U. S. Air Force, retired
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#14
July 25th 03, 02:27 AM
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#15
July 27th 03, 02:43 AM
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huge difference in the glide ratio of SR-71 & U-2
Yep. Like the difference between a lead-covered high drag rock and a feather. Well, in view of its speed, I doubt the SR-71 had high drag. I'd like to hear what Mary Shafer has to say about that. And "lead-covered...rock" seems to imply you think weight affects glide ratio. It does not. A U-2 constructed of lead would have the same glide ratio as one constructed of balsa wood. It would glide faster, but just as far. vince norris
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#16
July 28th 03, 12:09 PM
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#17
July 28th 03, 09:43 PM
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A U-2 constructed of lead would have the same glide ratio as one
constructed of balsa wood. It would glide faster, but just as far. vince norris Say what? Dave Um, I think there's be a slight difference in wing loading which just might have a minor affect on glide ratio. Translation: the lead U-2 would glide like a bowling ball. Dan, U. S. Air Force, retired
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#18
July 28th 03, 11:36 PM
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"Jack G" wrote in message ... Only in a vacuum would both "glide" at the same speed and go the same distance - I think. Jack In this case you are probably right but there is some truth in the assertion. Neglecting supersonic/transonic effects glide ratio is not effected by wing loading but the glide speed is. This is why we find that large airliners can have glide ratios comparable with many low performance sailplanes. The difference being that their best glide speed is probably an order of magnitude higher and so therefore is their rate of descent. In the case of a lead U-2 though I imagine that glide speed would be hypersonic  Keith
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#19
July 28th 03, 11:50 PM
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#20
July 29th 03, 02:22 AM
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Jim wrote:
On 28 Jul 2003 20:43:34 GMT, (B2431) wrote: A U-2 constructed of lead would have the same glide ratio as one constructed of balsa wood. It would glide faster, but just as far. vince norris Say what? Dave Um, I think there's be a slight difference in wing loading which just might have a minor affect on glide ratio. Translation: the lead U-2 would glide like a bowling ball. Dan, U. S. Air Force, retired What a wonderful question. Glider pilots often add water ballast, 200 - 300 lbs I think, to their gliders to increase airspeed at a GIVEN glide angle, thus improving the glider's penetration through the air at that glide angle. The extra weight does not alter the glide angle (except for very small improvements due to higher Reynolds numbers at the higher airspeed). The glider's descent rate is increased by the extra weight, but the airspeed is also equivalently increased so the glide angle remains (pretty nearly) constant, glide angle being a factor of only lift and drag, weight not even being in the calculation. As for a lead U-2 vs a balsa wood U-2, the lead U-2 would certainly glide as long as its wing loading was such that its wing could supply sufficient lift to sustain equilibrium in steady flight. The "catch" here is probably the inclination to picture the lead U-2 and the balsa U-2 as the same size. In such a case, if the lead U-2 were the same size as the gliding balsa U-2 I expect the lead one would do as you so delightfully describe, and glide "like a bowling ball". But why would you go changing things?...if you're gonna do that then you could have bigger wings, you could fit leading edge slats, you could do lots to give one or the other the advantage. I think that the only way to do these comparisons is to have big ballast tanks fitted over the CG then play with weight. Perhaps I'm getting old and slow but I'm having trouble seeing how a glider (or an aircraft) can glide ...better?... (farther/faster) when it's heavier. I really don't follow your description about adding ballast (above) at all...? -- -Gord.
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