In the first seasons of competition flying with FLARM in Germany a few people were turning on stealth mode, especially if they did not have a display to get any tactical data. Turning FLARM off was also observed regularly. Now I hardly notice anyone using stealth mode anymore. The initial fear of having a competitive disadvantage seems to have run dry.

Flarm is far from giving you a clear picture of the thermals ahead. On average the range is smaller than the distance you can see with your eyes, so your best bet for finding a thermal is still looking outside. There are occasions where Flarm brings another glider to your attention you would otherwise have missed but it is far from being a reliable thermal finder.

FLARM range is extremely variable. I fly a lot of club gliders with different antenna installations and I have seen gliders with carbon fuselage with hardly 2km of reliable range for collision avoidance. Especially to the rear a carbon fuselage will often completely block the Flarm signal so that a target flying right behind you will sometimes not be visible. In other cases I have had peak ranges up to 25km which usually only last long enough to display the target for a few seconds. A very good installation should give you fairly reliable contacts up to 4 - 6km and irregular peaks of up to 8-16km. Remember that the range always depends on antenna installation in both gliders. Even with a perfect installation you will not see some Flarm equipped gliders even on short range.

Flarm will give you some benefits in competition flying. Besides the advantages mentioned above it is particularly good for tracking what is happening around. You can marker specific targets to keep track of your team mate or see your progress against a selected competitor. It’s not like the range and reliability is good enough to leech someone outside your eyesight but you get an occasional fix of your marked competitor a few km ahead (or behind) giving you some sense of whether you are gaining or losing ground. Personally I enjoy this because it makes gauging my own performance a little bit easier.

The most useful feature of Flarm is still collision avoidance. You get a really good situational awareness of what is happening around you. Bad surprises of a glider appearing out of nowhere, hardly happen anymore.