Uir/fir
Legit question, no one can tell me at What’s the difference between a UIR and an FIR? I know that it’s a UIR= Upper flight Information Region and Flight information region, I see that altitudes are listed on charts but they are very straight forward, basically UIR correspond to class A. I fly basically in the US, Carib, and Central America, is this An ICAO thing? Is it just basically an FIR offering the same services but it differentiates to higher altitudes? For ICAO purposes... not like it has ever impacted me but I see the chart and wonder why have two things like FIR/UIR listed.