On Tuesday, February 6, 2018 at 12:14:40 AM UTC-6, jfitch wrote:

I can't speak for John's idea, but the hard deck I was think of would break that chain back when you could do something about it.

I've been skeptical of the idea that losing speed points will change low save behavior once it happens - the inconvenience and risk of landing out in that moment seems to me to be the more important factors.

This is a slightly different take on the argument - and somewhat similar to the logic associated with low finish penalties. Can you create a penalty incentive that is a realistic inducement for pilots to climb a little higher, or glide a little flatter, to avoid ending up hazardously low and struggling?

I think the answer for the two decisions is decidedly different. On final glides over a known distance to a known finish height, a penalty gradient can specifically offset the points spent to take extra time to climb slowly in the last thermal of the day. A steeper penalty gradient can even influence the probabilistic assessment of a pilot contemplating leaving a slow-ish climb in hope of finding a better one in the limited number of miles on the way home.

On the other hand, on-course decisions are much less certain. The distance to the next thermal is much more uncertain and (depending on where you fly) the altitude you don't want to get below because you'll need to slow way below McCready speed is much higher than 500'.

Flying in the Great Basin there are places where pilots start dialing back at 3-4,000 AGL. Even in flatland soaring I don't know of many pilots who are steaming ahead at 90 knots at 1,500' AGL absent a dust-devil in the next mile or two. So, what pilot is going to take extra turns in a thermal at 5,000 AGL in anticipation of potentially getting committed to landing out at 500' instead of 350' some 35 miles ahead? Even a pilot who's down to 2,000' AGL over the prairie wouldn't (it seems to me) make different decisions because they perceive they'd have a fraction of a mile (from the 500'-350' difference) less range to search for lift before a landout. My limit for giving up on pressing on is closer to 1,000 than 350' so for decision-making purposes I'm above the Hard Deck, not below it.

The "stop the dangerous decision chain before it starts" argument doesn't seem to me to work - at least not with a 500' hard deck. You'd need more like 1500' feet or more in the east and something like 2-3,000' in a lot of places out west. If people are not up for the notion of a hard deck at 500' it's hard to imagine anyone getting excited about one high enough to alter the decisions that (only in a probabilistic sense) matter.

Andy Blackburn
9B