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#1
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or fantasy of flight?
On page 52 of the September issue of Soaring magazine Jim Payne is listed as having flown an out and return course of 300 km at an average speed of an amazing ground speed of 189.62 MPH ! Can someone please explain how he did this when the Vne of the Arcus M is 174 MPH. It seems to me the only way to do this is to somehow fly (at Vne the entire flight),downwind, on both out and return legs. |
#2
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On Tuesday, September 20, 2016 at 7:01:26 PM UTC-6, Soartech wrote:
or fantasy of flight? On page 52 of the September issue of Soaring magazine Jim Payne is listed as having flown an out and return course of 300 km at an average speed of an amazing ground speed of 189.62 MPH ! Can someone please explain how he did this when the Vne of the Arcus M is 174 MPH. It seems to me the only way to do this is to somehow fly (at Vne the entire flight),downwind, on both out and return legs. Wave and altitude kick. Remember the higher you fly your TAS increases. That"s why speed and distance folks fly the great basin. Crusing at 16-18 thousand gets you a 30 Kt kick in TAS. Here's his story from the OLC. Best. #711. ___________ Pilot: Co-pilot Miguel Iturmendi. Mission was to fly a declared 300 km out-and-return between Inyokern and Big Pine. The forecast said the wave would be weak early with winds and lift increasing in the late afternoon. During the first lap, the wave was not good between Cindercone and Manzanar....the turn was covered in cloud. During the second lap, the lift was better...the speed was 278 kph. By the third lap, the lift was ripping and the clouds much better...the speed was 305.12 kph (189.62 mph)... Late in the day the Antelope Valley was overcast. We descended through a large hole in the overcast near California City. Had a Sage 2 clearance to FL290 in R-2508. For photos see www.tumblr.com/SoaringBlog. Thanks, Cindy for coordinating the Sage 2; Joshua for the outstanding service; and Doug T, Greg, Beth, & Jackie for crewing. |
#3
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Link doesn't work for me
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#4
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On Wednesday, September 21, 2016 at 8:28:43 AM UTC-7, Duster wrote:
Link doesn't work for me http://soaringblog.tumblr.com/ |
#5
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![]() Wave and altitude kick. Remember the higher you fly your TAS increases. That"s why speed and distance folks fly the great basin. Crusing at 16-18 thousand gets you a 30 Kt kick in TAS. Here's his story from the OLC. Best. #711. Tom, Thanks for the explanation. I recalled it as the other way around. |
#6
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On 21/09/2016 03:24, Tom Kelley #711 wrote:
On Tuesday, September 20, 2016 at 7:01:26 PM UTC-6, Soartech wrote: or fantasy of flight? On page 52 of the September issue of Soaring magazine Jim Payne is listed as having flown an out and return course of 300 km at an average speed of an amazing ground speed of 189.62 MPH ! Can someone please explain how he did this when the Vne of the Arcus M is 174 MPH. It seems to me the only way to do this is to somehow fly (at Vne the entire flight),downwind, on both out and return legs. Wave and altitude kick. Remember the higher you fly your TAS increases. That"s why speed and distance folks fly the great basin. Crusing at 16-18 thousand gets you a 30 Kt kick in TAS. Here's his story from the OLC. Best. #711. Pilot: Co-pilot Miguel Iturmendi. Mission was to fly a declared 300 km out-and-return between Inyokern and Big Pine. The forecast said the wave would be weak early with winds and lift increasing in the late afternoon. During the first lap, the wave was not good between Cindercone and Manzanar...the turn was covered in cloud. During the second lap, the lift was better...the speed was 278 kph. By the third lap, the lift was ripping and the clouds much better...the speed was 305.12 kph (189.62 mph)... Late in the day the Antelope Valley was overcast. We descended through a large hole in the overcast near California City. Had a Sage 2 clearance to FL290 in R-2508. For photos see www.tumblr.com/SoaringBlog. Thanks, Cindy for coordinating the Sage 2; Joshua for the outstanding service; and Doug T, Greg, Beth, & Jackie for crewing. Hats off to the pilots for their performance. But the above looks a bit extreme. So I did some checking. Google found me a copy of the "Flight Manual for Powered Sailplane, Arcus M" at http://www.schaenis-soaring.ch/filea..._M_AFM_ENG.pdf Around page page 38 of that document is a table listing Max permitted speed verses altitude. I listed 3 points in their hight band below and used my old circular flight computer to find the TAS at each of the altitude. Altitude (m) VNE (km/h) TAS (km/h) 7000 220 318 8000 207 320 9000 195 318 There is obviously a pattern above. To achieve an average cross country speed of 305km/h must have required operating right on the edge of the envelope for the entire flight. Ian |
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On Thursday, September 22, 2016 at 9:10:35 AM UTC+12, Ian wrote:
On 21/09/2016 03:24, Tom Kelley #711 wrote: On Tuesday, September 20, 2016 at 7:01:26 PM UTC-6, Soartech wrote: or fantasy of flight? On page 52 of the September issue of Soaring magazine Jim Payne is listed as having flown an out and return course of 300 km at an average speed of an amazing ground speed of 189.62 MPH ! Can someone please explain how he did this when the Vne of the Arcus M is 174 MPH. It seems to me the only way to do this is to somehow fly (at Vne the entire flight),downwind, on both out and return legs. Wave and altitude kick. Remember the higher you fly your TAS increases. That"s why speed and distance folks fly the great basin. Crusing at 16-18 thousand gets you a 30 Kt kick in TAS. Here's his story from the OLC. Best. #711. Pilot: Co-pilot Miguel Iturmendi. Mission was to fly a declared 300 km out-and-return between Inyokern and Big Pine. The forecast said the wave would be weak early with winds and lift increasing in the late afternoon. During the first lap, the wave was not good between Cindercone and Manzanar...the turn was covered in cloud. During the second lap, the lift was better...the speed was 278 kph. By the third lap, the lift was ripping and the clouds much better...the speed was 305.12 kph (189.62 mph)... Late in the day the Antelope Valley was overcast. We descended through a large hole in the overcast near California City. Had a Sage 2 clearance to FL290 in R-2508. For photos see www.tumblr.com/SoaringBlog. Thanks, Cindy for coordinating the Sage 2; Joshua for the outstanding service; and Doug T, Greg, Beth, & Jackie for crewing. Hats off to the pilots for their performance. But the above looks a bit extreme. So I did some checking. Google found me a copy of the "Flight Manual for Powered Sailplane, Arcus M" at http://www.schaenis-soaring.ch/filea..._M_AFM_ENG.pdf Around page page 38 of that document is a table listing Max permitted speed verses altitude. I listed 3 points in their hight band below and used my old circular flight computer to find the TAS at each of the altitude. Altitude (m) VNE (km/h) TAS (km/h) 7000 220 318 8000 207 320 9000 195 318 There is obviously a pattern above. To achieve an average cross country speed of 305km/h must have required operating right on the edge of the envelope for the entire flight. Ian The police won't come knocking on your door if you exceed the "permitted" speed. They're designed to 40% (?) above Vne and test flown to 20% (?) over. Yes, exceeding the Vne printed in the manual makes you a test pilot. That's part and parcel of world record flying. Don't try it at home. |
#8
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Designed and test to 11% above vne. Not enough margin there for any excursions above VNE..
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#9
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On Thursday, September 22, 2016 at 2:03:52 AM UTC-4, J. Nieuwenhuize wrote:
Designed and test to 11% above vne. Not enough margin there for any excursions above VNE. Never have seen it but I read that wave lift is very smooth and nearly continuous. This flight, so close to (or above) Vne, could not be done in thermal lift. There should really be two classes of records for these very different conditions. |
#10
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The design margins are far less than those indicated. More like 10-11 %.
Better not encourage breaking the limits. By the way, while practically all sailplanes can withstand higher g loads than required (recent wings generally fail at very high loads), the same can't be said about flutter resistance. On the other hand, a few models can be upgraded for increased flutter limits, probably by adding balancing masses and maybe improved control linkages. Talk to the manufacturer to search into it. Aldo Cernezzi They're designed to 40% (?) above Vne and test flown to 20% (?) over. Yes, exceeding the Vne printed in the manual makes you a test pilot. That's part and parcel of world record flying. Don't try it at home. |
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