A journey through 14 CFR 1.2 Abbreviations and Symbols
So, let’s talk AGL—yeah, I know… I choose exciting topics—and I’m not talking about your Aunt Gladys Louise, though she does have a few altitude-related opinions when she’s had too much to drink. Not judging, just saying… 🤷
AGL stands for Above Ground Level. That’s aviation speak for “how high up you are from the actual dirt below you.” Not the sea, not your ego, just the very patch of earth under your wings at that moment.
Why is this important? Because pilots, much like Roombas with trust issues, prefer not to slam into things unexpectedly. If you’re flying at 500 ft AGL, that means you’re 500 ft above the ground directly under you. If you keep that same altitude over a mountain? Congratulations, you’re now very much not 500 ft AGL anymore… you’re potentially one with geology. Not a good day!
AGL constantly changes with terrain, kind of like your mood during tax season. You can be cruising along at 2,000 ft MSL (i.e., mean sea level), feel fine, then suddenly the ground starts rising up like a Pixar villain and now you’re only 100 ft AGL and screaming, “Why didn’t I look at the chart?!”
So, the next time someone tells you they were flying “just 300 ft,” politely ask: “AGL or MSL?” If they say “I don’t know,” maybe don’t get in that aircraft.
Fly high! But more importantly, fly high enough!
Crock’s Thoughts 