On Monday, February 5, 2018 at 2:18:50 PM UTC-8, ND wrote:
On Monday, February 5, 2018 at 4:24:22 PM UTC-5, Kevin Christner wrote:
Bumping below as no response from any hard deck advocates:

1) Lets define a typical contest area as a circle with a radius of 75 miles from the contest site. Lets assume this is Elmira. In this area the valley floors likely vary +/- 300ft and often that much within 10 miles of each other. Creating an SUA file to account for this would be nearly impossible.

2) This is one more thing that will cause people to be staring in the cockpit instead of outside. Spending time looking at computers WILL lead to not spending time looking at potential landing sites. This WILL lead to accidents that would otherwise not occur. The question is will the hard deck prevent more accidents than it will cause. This is a question that would likely take 10 years of data to analyze. In the meantime the rule may cause more deaths than it prevents.

3) The rule will penalize perfectly safe flying. I remember a 60 mile glide in dead air coming back to Mifflin while in the back seat of KS. Detoured to Jacks a few miles west of the airport and arrived about half way up the ridge (250ft+/-). Minimum sink speed and on top of the ridge in 30 seconds, home for the day win. If the SUA had a 300ft hard deck in the valley we would have crossed under it on the way to the ridge save. Result - landout.

yeah, i'd like to see a SUA hard deck file that works for any of new york state... we land on the high ground, we land in the valleys. we also ridge soar 700 feet above the valley floor to make saves. there is no practical way to make a SUA file for Mifflin, Harris hill, blairstown, new hampshire, VT et cetera. the terrain is far too complex. maybe for a place like TSA, Hobbs, Ceasar Creek, or perry, you could implement it, but there are just too many places where you can be thermalling within proximity of higher terrain, while maintaining a good altitude margin above the surrounding area. google Mount pisgah in PA, and imagine a low save 500 feet above the peak of that mountain. there's just no way to make it sensical in areas of complex terrain.

Not that I'm in favor of the Hard Deck - I remain unconvinced that it materially affects pilot decision making and I think the argument that successful pilots systematically use low thermalling as a tactic has scant evidence to support it. Nevertheless, the above criticisms probably aren't the main ones, or even correct. The idea was to define the hard deck only above the lowest terrain you could reasonably glide to and in discrete steps MSL so it isn't continually varying. So it's not clearance form the ridge below you, it's clearance from the bottom of the nearest, lowest valley. That means there would be no hard deck at ridges higher than 500'.

It probably gets complicated if you need to soar 500' ridges or over wide escarpments adjacent to lower valleys (from what height can you clear the edge, shifting the landout option from on top of the escarpment to the valley?), but those situations are quite a bit rarer. For those of you who have ever flown on a day with morning valley fog with the mountains poking out, it's kind of like that.

As I said, I'm not a fan of the proposal, but we should probably stick to discussion of what was actually proposed or everyone will get confused.

Andy Blackburn
9B