I’d agree that the number of regional aircraft will decrease in the future, but fuel cost coupled with the age and unpopularity of the 50 seaters will be more of a determining factor than environmental brownie points. If fuel stays cheap, aging and inefficient types could stick around for a while. If fuel goes up significantly, the smaller jets could be retired fairly quickly and replaced with reduced frequency on bigger planes. United for instance will be taking delivery of 94 aircraft over the next two years and will have plenty of lift available. Should be an interesting couple of years to see how the industry comes back.

Except what they are “OK” with doesn’t change the geometry a bit - not if they truly want a smaller carbon footprint. Current regional flying just won’t provide that result. Lower frequency would, small turboprops would, electric eight or twelve pax short range aircraft would. But flying someone 100-200 miles south or north so they can land, taxi in at a crowded hub, unload, then reload, taxi out at a crowded hub, to then travel 1500 miles East or West is going to be pretty counterproductive if you are trying to save on carbon footprint.

They'll have to get at the carbon some other way, SAF or possibly even battery power for some short-range EAS type ops.

Reduced frequency only works up to a point: six flights/day vs. three is a competitive advantage, but the pax would tolerate 3/day of that was the only option. But three flights/week is a non-starter in the US, we're too busy. In the developing world it's OK to have 1-3 flights/week, slower pace of life, a couple extra down days to groom your camel and chew khat is no big thing.

Serious question, does anyone know how a 50 seat RJ compares with a reasonably modern car? Which has a bigger carbon footprint per mile? If we curtail the short haul 50 seater flights, I'm guessing we'll just incentivize driving? Might be a good thing (carbon footprint wise) if pax travel from COS-DEN in a packed 15 pax shuttle-van. Maybe not such a good thing if the pax all drive their F-150 to DEN.

Serious question: Have you ever looked at the economics for EAS flights? Or the Amtrak station in Fargo ND that gets one Amtrak Empite Builder stopping at 0324 in the morning three nights a week? The train weighs 1.08 MILLION pounds and will
slow from 50 mph to a stop to pick up (or drop off) one passenger, then accelerate back up to 50-70 mph. Just figure the energy requirements of that - and it’s all fossil fuel - and then repeat that for Cutbank Montana and every other little whistle stop on the way to Seattle. DO THE MATH.

Congress doesn’t really give a rats rear about CO2 release. They just want the votes of those who do give a rats rear about carbon release who they can play like the fools they are.

My opinion. Later in this decade, bridging the gap between the 76 seat RJs and the A320 & 737 metal will be new A220s and used A319s (I doubt Airbus will want to build new A319s when they are selling the A220s.). Those look like the ideal fit at the bottom of the majors (AA terms it Group 1 pay, with the A320s & 737 as Group 2 pay).

50 seat reduces to much fewer, replaced by 76 seat lift. Much of current 76 seat will be replaced by A220s.

Not only carbon footprint, but gate availability and as the pilot shortage reemerges.

That is what my crystal ball says.

Actually, Airbus IS making new A319 NEOs. NK has a number of them on order:

https://www.airbus.com/aircraft/pass...y/a319neo.html

Well I just learned something new. I had zero knowledge that a 318 existed in the 320 family.

Aka the short, short bus.