TECHNOLOGY / Just out of reach A helpful safety tool that's not infallible BY DAVE HIRSCHMAN GL IDE R INGS ARE a powerful safety tool that tell pilots at a glance whether they're close enough to an airport to glide to it- but how trustworthy are they? Dynon, Garmin, and ForeFlight all offer glide rings that can be displayed on moving maps, primary flight displays, tablets, and iPhones to visualize emergency landing site options in the event of an engine failure. The graphical tools show pilots how far they can expect to glide following an engine failure and point out any airports in that area. ForeFlight ForeFlight introduced its graphical Glide Advisor in 2017 and credits it with several " saves " in which pilots successfully glided to safe airport landings after an engine failure. Glide Advisor uses manufacturerderived glide ratios for FAA-certified aircraft but allows users to customize them based on their own airplane's performance. Unlike some other apps which link their glide safety features to proprietary autopilots and onboard flight data computers and display them on panel-mount AOPA PILOT / January 2025 81