Re: Pikes Peak Ceiling Climb III
For the PPCC in 2007 I asked Mark Drela about this issue. Mark sent me some calculations that showed the increase in sink rate for a 6000' altitude increase to be about 12% and the decrease in drag on launch to be about .833X. My understanding of his conclusions is that a glider that is maxed out in a Cat 1 site at sea level should do about the same flight time in an unlimited ceiling height at an altitude of 6000'.
For my standard class gliders that can barely reach a full height Cat 1 ceiling this is about the result that I get. I was doing mid thirties at home and about the same in Colorado (before various bad things happened). My unlimited glider did better times in Colorado (as did my previous one) because it will launch considerably higher in Atlanta than Cat 1. In Atlanta I used a loop .042 x 4" and could hit the ceiling at 28' easily. In Colorado I used a loop .058 x 4" and was launching to within a foot or so of the 37' peak of the room. This gave me a flight time about 5 seconds better in Colorado than in Atlanta.
----- Original Message -----
From: hermann andresen
To: construction Indoor
Sent: Tuesday, March 31, 2009 1:05 PM
Subject: RE: [Indoor_Construction] Pikes Peak Ceiling Climb III
Sorry,
Was speaking about CLG only. Because of drag/wt ratio, there are dozens of neg g's off the launch & thinner air lets decreased g's help offset the increased glide speed.
Having flown EZB in 7000' Lumberjack dome in Flagstaff I totally agree re rubber. Thought it would take a Coupe motor to get it to climb.
BTW the dome is interesting geodesic w/insulation almost flush w/structure & difficult to hangup. Also hard to hit 150' ceiling. Is conveniently close to I-40, I-17. Great site.
Pardon the confusion re climb,
H
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To: Indoor_Construction_at_yahoogroups.com
From: ddeloach_at_comcast.net
Date: Mon, 30 Mar 2009 21:19:43 -0600
Subject: RE: [Indoor_Construction] Pikes Peak Ceiling Climb III
Not sure what to say about this. Just come fly at 6000 ft and see how many National records you set!
Besides, improved climb doesn’t mean squat in low ceiling indoor where you do everything you can to LIMIT climb (variable pitch, backoff, etc)
Having said all this it still was a great contest at which we were all disadvantaged equally!
DD
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From: Indoor_Construction_at_yahoogroups.com [mailto:Indoor_Construction_at_yahoogroups.com] On Behalf Of hermann andresen
Sent: Monday, March 30, 2009 8:35 PM
To: construction Indoor
Subject: RE: [Indoor_Construction] Pikes Peak Ceiling Climb III
I originally thought that improved times were possible _at_ SL, but that ignores the improvement in climb with thin air. Actually cold actually helps because viscosity decreases (opposite of liquids) which helps both climb & glide.
One's Opinion,
H
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To: Indoor_Construction_at_yahoogroups.com
CC: MMMFreeFlight_at_yahoogroups.com
From: ddeloach_at_comcast.net
Date: Mon, 30 Mar 2009 14:16:45 -0600
Subject: [Indoor_Construction] Pikes Peak Ceiling Climb III
It was a terrific day, with 22 paid flyers. The biggest indoor meet in MMM history (though several regular flyers were not there).
Bill Gowen won ULCG with a best flight of 44+ and two 45+ unofficials. This was a really outstanding performance by Bill; it smashed his own site record from 2007. This morning when I drove Bill to the airport I opined that a :45 would probably equal 49-50 seconds at sea level. That would be a .75 to .72 ft/second sink rate!
Todd “The Arm” Reynolds won HLG; Romash and “Alfons” won SCLG. Times in these weren’t remarkable (34-36s).
Kagan won the F1D regional easily with 2x 18:00+. Romash dominated F1L with a new site record. Romash also won EZB and LPP. Gowen scored another site record in A-6 with 5:39.
Grand Champ was really close. Romash pipped Gowen by only one point, 20 to 19. Gowen barely got second in F1M and did not score any points in SCLG, otherwise he would’ve won.
Rgds
Don D.
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Received on Tue Mar 31 2009 - 16:47:20 CEST
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