In article ,
"Marc Ramsey" wrote:

If I plug MC 10 knots into my speed to fly spreadsheet for my LAK-17A
18M dry (which is likely to have a higher STF than your IIC for the
same MC setting), I get 148 mph (130 knots) for 0 airmass movement.
In order to get an STF of 200 mph, I would need to be in 10 knots of
sink.

Which is not at all impossible in the mountains!

-- Bruce