• Do use the speed-to-fly function of the electronic vario, preferably with sound; it is a great wake-up call wey every time one is tempted to dillydally about in bad air. Plus the speed-to-fly sound saves a great deal of workload in terms of thinking about what would be the ideal speed; it just commands it.
• Do not follow the speed-to-fly sound slavishly, but softly in its tendency, and never forget that any vario information is information from the past, while only the pilot can look ahead and into the future (admittedly with varying quality of her/his powers of prophecy...).
• As to McCready settings, do not bother with too fine adjustments; one knot steps do fully suffice. I use a very simple "five-speed gearbox."

(0 kt: never use MC zero, it just makes you far too vulnerable in case of sudden sink, especially with an unballasted club class ship)

• 1 kt: minimum MC setting for all situations of mere survival: setting off in the morning in the first weak thermals; reaching that last chance for a thermal; stretching the glide before an inevitable outlanding; bringing her in on a long, marginal final glide; working your way home in the evening in the last weak thermals
• 2 kt: MC setting in generally weak weather, or below-average weather combined with other difficulties such as few outlanding fields, unknown landscape, etc. A very very careful setting.
• 3 kt: Seems to be my most commonly used MC setting, typically in predictable, reliable weather with normal thermals.
• 4 kt: MC setting for good, above-average conditions, reliable lift, high cloudbase, well marked thermals, an everything's-just-fine MC setting.
• 5 kt: My personal MC setting for throttle fully open.

6 kt: will of course deliver higher average speeds in very good weather in a classic climb-glide-climb-glide situation, but in the Alps strong weather always brings good lifting lines and I had the impression that with a MC setting of 6 kts I ran a higher risk of dropping out of those lifting lines, thus being forced back to a climb-glide-climb-glide strategy which consumes quite a big deal of the higher speeds.

I know I am not too much in line with classical speed-to-fly theory with this, but from all flying my personal opinion is that the optimum McCready setting for a given situation is not too closely related to the climb rates achieved or expected. Instead, I try to boil my whole assessment of everything that is in any given situation of flight down into something like a "throttle setting". So, climb rates do go in there, but also cloud base altitude, reliability of the clouds so far, any difficulties experienced, my current altitude, my personal level of knowledge of the landscape ahead, and so on, and so on. All this goes into that "throttle setting", i.e. the MC setting, and this in turn ensures that the speeds chosen will fit to the situation (and to the whole situation, not merely mathematically to some climb rate value found previously or expected ahead).

The habit of using this "five-speed gearbox" with its five McCready settings evolved from flight experience only, so no particular features of my polar have contributed to the choice of these five settings.

The polar is, of course, implemented in my speed-to-fly calculator (my electronic vario, that is), so that any McCready setting leads to the appropriate speed being commanded by the calculator.

As to the numeric values of the MC settings in use, mine will probably do as a starting point. Depending on where you fly, they will probably need to be adapted to typical weather conditions in your area. For example, in an area with typically high cloud base and strong lift, but long glides in between, the "throttle fully open" mark will probably need to be at a higher McCready value, say at 7kt (3.5m/s) or even 8kt (4m/s). Also, some adaptation to pilot preferences might be required. The type of glider however will not make much difference, simply because this is cared for by their different polars; same with ballast.

I think using five settings suits human perception and psychology well, because it gives you one "normal" value in the middle, with one "very bad" and one "rather bad" on the one side and a "rather good" and a "very good" on the other side. It seems to be quite simple to categorize even complex soaring situations into one of these five settings. Using more settings makes this assessment more difficult, and classic speed-to-fly theory shows that mathematically five settings are fully sufficient, errors caused by the steps in between are negligible.

Also, I think that the rule of never using a McCready value of zero is applicable to all gliders. It is of course theoretically true that a zero setting maximizes gliding distance from a given height, but this is static theory, i.e. while it does take constant air mass movements into account (and holds true for constantly rising air or constantly sinking air), it does not depict *changes* in the vertical air mass movement, particularly not the dynamics of a glider entering into sudden sink. Flying at MC = 0 leads to very slow airspeeds (on an unballasted Std. Cirrus theoretically only about 50kts) and consequently high vulnerability to such variations in air mass movement. A slightly higer McCready setting allows a significantly higher airspeeds (Std. Cirrus 60kts @ MC=1kt) at the price of a marginally reduced glide ratio. This pays off as soon as you hit sink: part of the increase in speed now required is already done, and the remaining speed needed is picked up much quicker.

For more, including diagrams analyzing Jan's flight history, see Cross Country Flying.

This is a critical safety issue of the highest order! If your glider is among the serial numbers 21, 23, 27, 30, 32,-34, 36-52, 54-120, then, if you have not already done so, inspect the lower bearing in the elevator for compliance with the following technical note. Do it before you fly again!