Thread: Hard Deck
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Old January 28th 18, 07:01 PM posted to rec.aviation.soaring
Steve Koerner
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Default Hard Deck

On Sunday, January 28, 2018 at 8:38:49 AM UTC-7, John Cochrane wrote:
There you go again overcomplicating things ... Just because it's hard to define a SUA that rules out all the problematic high terrain out of Logan or Nehphi does not argue against a simple altitude floor at Hobbs, Uvalde, or all the east coast flatland sites. It does not argue against valley floor SUAs even at those complex sites. Again, we are not here to stop bad behavior, to control what pilots do, and so forth. We are just, where we can with a simple transparent means, removing the strong incentive for SOME dangerous flying. Not all. Not at all sites. Not at all parts of all sites.

There is a lot of speculation around here. I used to do the numbers for the SSA safety report. We had a seriously damaged glider or worse in about one of every two contests. Almost all the damage was off field landings gone wrong, and almost all the traces showed low altitude thermaling attempts before crash. The reports are still on the SSA webpage. (Before the cylinder, we used to have regular crashes at and around the finish too.) Smacking into terrain or midair collisions are present, but quite rare.

On the elevator. I was skeptical too. Then I tried it. It's pretty benign.. You float down the eastern shore of Tahoe with an easy bail out to minden or carson most of the way. The ridge lift is very predictable. If there are whitecaps on tahoe, there will be ridge lift. The wind has to go somewhere. If there are not whitecaps on tahoe, it's not going to work. Smooth ridge lift gives you enough for a very comfortable glide back in to Truckee.

I see how it can be overdone. I have seen some traces of pilots shooting through the gap from the west, coming around the corner very low and squeezing lift out of the elevator from low altitude. That's a little hardy for me, in part that the back through the gap escape is gone. So far I have only tried it from about ridge top height up.

John Cochrane


John - Thanks for the discussion on the "Elevator". I suspect that Sergio, at one point or another, did a good job of explaining that conservative approach and it didn't sink in with me. I'm certainly willing to try it the way you describe.

Regarding the hard deck idea, there have been two rationales expressed. One relates to safety -- protecting us from temptation of dangerously low saves. The other rationale relates to fairness -- not wanting a fellow competitor to get advantage by doing something that I would never do. Let's dissect that second rationale a bit.

I think the difference in AGL altitude at which BB or GW would safely quit turning and start landing and the lower altitude at which dangerous Joe Blow might risk his life and limb is not really very great. Wouldn't you say it's only around 150 feet? In most cases Joe Blow won't get any sort of advantage from doing so because he'll end up landing at that location regardless of his treachery. In the scheme of things, 150 feet isn't much. Certainly it is less than the typical variation in starting height between gliders on any given day.

The hard deck idea introduces an uncertain stopping point which is actually a lot greater than 150 ft. It's uncertain because, when low, we are normally gliding to or around landing alternates based on visual clue. Hard deck cannot be so easily judged or anticipated along the way. The height at which you are hit by hard deck would depend on where exactly the glide-to terrain elevation is in your step structure and it would depend on the present error of your pressure altimeter. There would be considerable variation in those factors between competitors who might be snagged by the hard deck and that is itself unfair.

In considering the fairness rationale, it would seem that this is a case that the cure is worse than the disease. If the fairness argument doesn't really work, the discussion needs to focus exclusively on whether or not there would be a realistic improvement in safety and whether or not added rules and complications are worth that improvement and whether or not the reduction in each pilot's liberty to find his own way to the finish line is worth it, as well.