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#21
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Here's the solution to the problem that someone might be tempted to
dive for the base of the finish cylinder and do a radical pull-up, as well as the problem that someone might try to thermal at 300' to get up to 500' and save himself the rolling-finish penalty: There is a donut of airspace, from 1 mile radius to (say) 4 miles radius, with top at 500 feet (or finish cylinder base, if higher). This is forbidden airspace, marked in the sua file as such. One fix in that airspace, and you've landed out. (Or, if you feel that's too much, it gets you a 100 point penalty, plus any rolling finish penalty or time addition.) Essentially, we create an airport located in a 1 mile radius valley, surrounded by a plateu at 500 feet. Now the optimum thing to do for a pilot who cares even zero about his own safety is to fly about 90 kts (regular glide speed) to about the 2 mile radius and 501 feet, then let speed bleed off to the average speed for the flight at the 1 mile mark. Of course, sensible people will just fly 90 kts to the 550' 1 mile point, with trivial loss of points. (It's not efficient to end up as slow as possible at the 1 mile mark. To see why, imagine you could fly at 0 airspeed. Taking 10 minutes to go the last 100 feet would not make sense. If you flew 60 mph average for the flight, flying level at 59 mph slows you down, while flying level at 61 mph increases your average speed. Thus, you want to cross the line at the average speed for the flight, 60 mph in this case. 5-10 kts extra cost hundredths of a point.) There is no incentive for low-altitude thermaling just outside the cylinder. Once you're below 500 feet (or 1000, or whatever the top of the donut) you landed out so you might as well glide home. (If it's 100 points plus the rolling finish penalty, you just got the rolling finish penalty, so again you might as well stop screwing around and go land.) If you're 5 miles out and you can't make it over the donut (about 1200 feet is the decision height here), you have every incentive to stop; either thermal at a decent altitude or find a decent landing place. It's just like not being able to cross the final ridge into the airport. There is no need for a rules change to do this. CDs may now designate any airspace they want to as off limits. Just put the donut in the sua file. Any CD or contest manager who wants to ensure really safe finishes can put this into place now. The donut can also be used with a conventional finish line. This will ensure that pilots arrive at the airport with plenty of energy, or already committed to rolling. John Cochrane BB |
#22
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At 20:00 29 March 2005, Bb wrote:
Here's the solution to the problem that someone might be tempted to dive for the base of the finish cylinder and do a radical pull-up, as well as the problem that someone might try to thermal at 300' to get up to 500' and save himself the rolling-finish penalty: There is a donut of airspace, from 1 mile radius to (say) 4 miles radius, with top at 500 feet It's the Krispy Kreme finish! It's appealing as a disincentive to cylinder antics and has the additional virtue that it ensures adequate energy for gate finishes since 500' gets most gliders roughly to redline at 50' over the airport. Since the main complaint about gate finishes is inadequate energy for a pattern this basically forces a rolling finish decision at 1 mile or more if you don't have the energy. I'm assuming you don't get the penalty if you do a rolling finish. I would also allow the CD some discretion over penalties since 499' and 150 knots is not the same as 499' at 40 knots. Pretty interesting - I think this came up last year didn't it? 9B |
#23
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Or how about this for a solution. The start cylinder has a top, right?
It actually extends well beyond the boundary of the cylinder. If you go above this top, you must come back below it and remain below it for two minutes before you can get a start without incurring a penalty. We all know the rule. How about a similar, but inverted plane and system at the base of the finish cylinder? One data point below the base of the finish cylinder, and you cannot get a finish until you have been above it for two minutes. Or, maybe make it five. Might as well go take your rolling finish if you dip below it on final glide. It is much easier to apply the same rule two different places than to try and come up with something else, IMHO. Will certainly stop ballistic trajectories, but not the level decel. Don't get me wrong, John. I like donuts, but in the morning before the Pilot's Meetings! Steve Leonard ZS |
#24
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If we were to have 4 cylinders (only one of which would be in use any given
day), such that the cylinder's edge was more or less down the centerline of the runway (one on each side); or perpendicular to the runway (one at each end), then, other than altitude, the spectator appeal is about the same as with a line. (We ought to change the subject of this thread.) -- Bob bobgreenblattATmsnDOTcom --fix this before responding |
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