MC Setting for a Safe Final Glide
A few weeks ago I mentioned setting a MacCready setting of 2 (MC=2) for flying between thermals and follow your speed director. Remember too much time and energy can be spent looking inside to fly the perfect speed. If you miss the next thermal you land-out or get stuck.
But what about getting home? How do you establish a safety margin? Back as a new student you probably cut the glide ratio in half. Maybe as you gained more experience you reduced the safety margin a little.
Using an MC=2 isn't all that safe (in some conditions) for calculating the final glide as your computer is doing. Especially when you are flying that speed, its easier to fall below glide.
Use your MC settings to give yourself a safety margin. So what MC setting should we use?
A good way to increase your odds of making it home is with an MC=6. Then fly a 2.5, flip over make sure they could make the 6, then slowly bump up your flying MC setting. This gives you the same safety margin for the entire glide vs just setting 1000 ft over the airport. A 1000 ft safety at 2 miles is different than at 20 miles.
When I coached the US Juniors at the JWGC. I recommend they come home with an MC=6 because of large areas of sink around Narromine. We would then watch other finishers and monitor frequencies to get an idea if it appeared to be sinking or rising air on glide. We could then have them modify as necessary.
In areas where the conditions are less extreme an MC=4 might be plenty safe. Day 4 of the SGP in Ionia I used an MC=1.4 because that was as high as we could get.
This is not to say you couldn't start your final glide 50 miles out, 8000 ft below glide and make it without turning by using the energy better. But the last thing you want to do is end your flight in a field 3 miles from the airport.
Many accidents happen close to the airport and trying to select a suitable field from a low altitude.
Banner Photo: Tobias Barth
ClearNav Vario - ClearNav Instruments vario system has been designed to provide glider pilots with the best possible climb and speed-to-fly guidance, as well as valuable secondary information, including wind speed and direction, air and ground speeds, and altitudes.
Nano III is a small IGC flight recorder with a 56-channel GPS receiver and allows up to 14 hours of stand-alone operation with its built-in battery. This flight recorder comes with sunlight readable LCD screen displaying task and waypoint navigation. It also has a built-in variometer.
Garret Willat holds a flight instructor rating with over 8000 hours in sailplanes. His parents have owned Sky Sailing Inc. since 1979. He started instructing the day after his 18th birthday. Since then, Garret has represented the US Junior team in 2003 and 2005. He graduated from Embry-Riddle with a bachelor's degree in Professional Aeronautics. Garret represented the US Open Class team in 2008 and 2010 and the Club Class team in 2014. Garret has won 3 US National Championships.