Alaska's small planes get until 2034 to upgrade altimeters — if they fly Outside

Alaska's air taxis, floatplanes and small planes have until 2034 to upgrade a key safety instrument — but only if they fly to the Lower 48.

Under a final FAA rule, aircraft equipped with radio altimeters must retrofit them to withstand wireless interference by Oct. 31, 2034. Radio altimeters measure a plane's height above the ground and feed terrain-warning and low-visibility landing systems — the equipment that matters most in Alaska's mountains and weather.

Operations flown only within Alaska are exempt. The deadline kicks in only when an Alaska aircraft enters covered airspace outside the state.

The driver is 5G. The FCC is opening a slice of the airwaves near the frequencies altimeters use to wireless bidding, and those signals can interfere with the instruments — the same conflict that snarled flights when C-band 5G first rolled out a few years ago. Large carriers must comply sooner, by the end of 2030.

The FAA pegs the national retrofit at up to $7.1 billion, with the rebates aimed mainly at airlines. Alaska's smallest operators get the most time to comply and, on slim margins, the least room to absorb the cost.