There's an infinity of scenarios. In the mountain sites I mostly fly, there are final glides that are predictable winners and others that are almost guaranteed to be losers. One common one for me into my home club (at day's end) has a last likely thermal source 20-some miles out, with a glide over a river valley that is normally a net loser, followed by four or five miles of completely unlandable terrain, followed by tall trees, then our airport, which is pretty much a bowl scooped out of higher surrounding terrain and is famous for obstructions on the runway (some with legs, some with wheels, some with large fabric envelopes filled with hot air) that you won't see until you are right there. I usually set that final glide up with MC=2.0 plus 1400. I pretty much always show up high enough to assess landing options, then "check the compass" against the appropriate runway heading, and that's the way I like it.

1400 is silly high for many sites, especially out in the flat lands.

On a wave day at Sugarbush, 1500 may not be enough.

If the wind is blowing, MC goes up because uncertainty goes up (another alternative is enter a manual wind, but that's more work). A stiff tailwind usually means wind shear which means your fat final glide may go "poof" when 25 kts at altitude runs into something less down low. Or you may run into wave sink, or whatever.

If wind is blowing hard across mountains or ridges, then most often I'm not flying a final glide per se... I'm "soaring home" on ridges or wave and the objective is to get there at sufficiently high altitude that I can deal with any conceivable nonsense (wave sink, rotor, what have you) when I get there.

I normally don't set MC higher than 3.5 for final glide. About the time I feel like I might need MC 4.0 (for safety) I'm thinking a final glide in the usual sense isn't such a hot idea.

best,
Evan Ludeman / T8

On Monday, October 3, 2016 at 6:28:12 PM UTC-4, Jonathan St. Cloud wrote:
The below is what I do, but I had not actually thought of putting in a higher MC than flying with at the time of final glide. Just curious about using a higher MC, when do you input this value, before beginning final glide or while I glide. If the day is still active I began final glide before I have arrival altitude.

On Monday, October 3, 2016 at 3:14:32 PM UTC-7, Tango Eight wrote:

There is no one safe arrival height.

The correct course of action is to let the computer report your estimated arrival height at your destination (f(MC, wind, ballast, bugs) and then do that PIC thing.

Evan Ludeman / T8