5 February 2026
Garmin has received approval of its GHA 15 height advisor for certified aircraft – it has previously been approved only for experimental aircraft.
The GHA 15 is a small and lightweight height advisor that uses radar technology to provide height above ground level (AGL) information, displayed on compatible GI 275 electronic flight instruments.
The US authority, the FAA, has granted Supplemental Type Certificate (STC) approval for the installation of GHA 15 in more than 500 certified class I & II aircraft.
🔊 SOUND UP FOR TOUCH DOWN 🙌
Hear our GHA 15 height advisor provide radar-based AGL altitude readouts for ErinandPaulFly 💪 🔟
Available for select certified and experimental installations.
Bearhawk Aircraft Five#GarminAmbassador pic.twitter.com/6AseJYQ0hN
— Garmin Aviation (@GarminAviation) February 27, 2026
The GHA 15 calculates height AGL by sending radio waves to the ground and determining the time it takes to receive the signals back. It processes hundreds of measurements per second and applies advanced digital filters to maintain continuous readings – even over water or in challenging terrain environments.
AGL readouts are shown on the GI 275 electronic flight instrument at altitudes as high as 500 feet AGL. Using the readings provided by the GHA 15, the GI 275 can also provide AGL audio callouts to help keep the pilot’s eyes looking outside the cockpit.
Height readout on the GI 275
Beginning at 300 feet, the pilot will hear audible AGL altitude callouts at select intervals down to 1 foot AGL. The pilot can configure the callouts to start and stop at specified altitudes. Knowing precise height AGL can be helpful to pilots during landings and flying in areas where limited barometric altimeter setting information is available – such as backcountry flying.
Garmin’s new GHA 15 radar altimeter mounted on the underside of the fuselage. Photo: Ed Hicks
The single module integrates all electronics into one compact unit that attaches to the bottom of the aircraft. It’s slightly larger than a pack of cards and weighs less than one pound.
The Garmin GHA 15 is available now for certified aircraft at a suggested retail price of $2,695.
