Is the 200ft below Min Finish Height Rule Working?

On Tuesday, January 21, 2014 7:14:15 AM UTC-5, J. Nieuwenhuize wrote:
Op maandag 20 januari 2014 21:21:11 UTC+1 schreef : On Monday, January 20, 2014 3:03:41 PM UTC-5, J. Nieuwenhuize wrote: Why not use the total height? So height (AGL) plus potential height (speed²/(2*a)) That makes ballistic pull-ups useless, allows, actually favors smooth finishes. Then set the total height rather high and substract one point per feet too low. Simply put- because this becomes a pilot and scoring nightmare. Note that each glider converts kinetic energy to potential energy differently. UH Not really; in fact they do it exactly the same way. Even an unballasted club class glider looses only a few percent (due to drag during the pull-up). Since virtually all pilots fly with a TE energy system and rely exclusively on it, I highly doubt it'd be a pilots nightmare. The ideal finish with a fixed height finish line/circle (or point substraction when too low) is fairly straightforward; fly at best MC, say 100 kts and pull up agressively, just before the finish ring. Exactly the opposite of what you'd want... A hard deck within - say - 4 miles from the finish line is a simple alternative. Get below finish height and you're scored as a land-out.

You are suggesting an alternative that requires computation in the cockpit to allow for kinetic energy and then asking the scorer to do the same. The current systems use direct measurement of one attribute (height) measured with a simple existing instrument and easily verifiable by the scorer.
The glide final scenario you describe is actaully not optimum. A perfectly flown ending has the glider at a fairly low speed, roughly the average speed for the task,and does not have a big pull up.
UH

Op dinsdag 21 januari 2014 14:28:50 UTC+1 schreef :
On Tuesday, January 21, 2014 7:14:15 AM UTC-5, J. Nieuwenhuize wrote:

Op maandag 20 januari 2014 21:21:11 UTC+1 schreef : On Monday, January 20, 2014 3:03:41 PM UTC-5, J. Nieuwenhuize wrote: Why not use the total height? So height (AGL) plus potential height (speed²/(2*a)) That makes ballistic pull-ups useless, allows, actually favors smooth finishes. Then set the total height rather high and substract one point per feet too low. Simply put- because this becomes a pilot and scoring nightmare. Note that each glider converts kinetic energy to potential energy differently. UH Not really; in fact they do it exactly the same way. Even an unballasted club class glider looses only a few percent (due to drag during the pull-up). Since virtually all pilots fly with a TE energy system and rely exclusively on it, I highly doubt it'd be a pilots nightmare. The ideal finish with a fixed height finish line/circle (or point substraction when too low) is fairly straightforward; fly at best MC, say 100 kts and pull up agressively, just before the finish ring. Exactly the opposite of what you'd want... A hard deck within - say - 4 miles from the finish line is a simple alternative. Get below finish height and you're scored as a land-out.



You are suggesting an alternative that requires computation in the cockpit to allow for kinetic energy and then asking the scorer to do the same. The current systems use direct measurement of one attribute (height) measured with a simple existing instrument and easily verifiable by the scorer.
If you dumb it down enough, there'll be a point where it's a simple "get up and fly as far as you can". YMMV, but the hard deck is a simple alternative, to which I can't see any major drawbacks..

The glide final scenario you describe is actaully not optimum. A perfectly flown ending has the glider at a fairly low speed, roughly the average speed for the task,and does not have a big pull up.

Yes, it is the optimum. If you fly from a given point A with a given lift to a given point B, ignoring sink or lift during the final glide, flying mac-Cready, while decreasing the altitude of point B with the potential height from the given MC gives the smalles time and thus the highest speed. Then you'd fly @ MC till you're below point B and pull up vertical. With a ground-level finish this is impossible, but flying MC until you're near the ground and coasting out in ground effect then is optimum (least time taken=highest speed)