Which aircraft are used by U.S. regional carriers?

I was thinking about regional airlines. In the '80s the now-defunct PSA used BAe 146 aircraft. I’d always thought they were neat-looking. (I generally like high-winged aircraft.) I can’t remember the last time I saw one. So that got me wondering which aircraft are used by regional airlines in the U.S.

Off the top of my head:
[ul][li]Boeing 737 series[/li][li]McDonnell-Douglas MD-80[/li][li]Airbus A320[/li][li]de Havilland Dash-8 series (now Bombardier Q-series)[/li]Embraer EMB-120 Brasilia[/ul]

I fly American Eagle fairly frequently, usually on a Canadair CRJ or Embraer 135/145. I seem to recall Comair Delta Connection using Embraers, but they are now operating CRJs exclusively.

Great Lakes Airlines uses the Embraer Brasilia and the Beechcraft 1900D.

Fokker F100 (?).

I don’t think I’ve seen any of those Fokkers.

The Fokker F100s, besides being an “orphan” design with the demise of the company in 1996, was driven out of service with US carriers in the early-mid 2000s due to uncompetitive economics vs. the A319 and new-generation 737 at the top of the market, and RJs at the bottom.

Johnny, we may need to consider a definition distinction between “regional airline” in the generic sense of any smaller-sized airline that only covers a limited market, and the industry-jargon meaning of “regional airline” as the feeder services that serve small airports or thin-volume routes with connections to the hubs of the major airlines.

This is significant in that from your list, the 737, A319/320 and the MD80s are considered “main route” airliners, for the purposes of the union rules and and codeshare contracts that regional affiliates have with the national carriers (e.g. Delta Connection, American Eagle, USAir/United Express, Air Canada Jazz, etc.) to determine who flies what flight (e.g., ATL-CVG on a CRJ = Comair/Delta Connection plane/crew; ATL-CVG on a MD87 = Delta plane/crew). This has raised a new issue with the introduction by EMB and Bombardier of 90/100 seat RJs, which puts them close to the capacity of an A318, 737-500, MD95(B717), or the old DC9-10/20.

My entirely unscientific sampling from airport-watching and airline-magazine/website reading has the following results WRT regionals:

Beech 1900 and derivatives
SAAB 340
Bombardier Dash-8/Q400
Dornier Do328
Small carriers doing small-volume small- or remote- airport routes still use DHC-6 Twin Otters, Britten Islander/Trislander and even Cessna Caravans and 414s, a-la the TV show “Wings”.

Bombardier CRJ (-200 to -900)
EMB ERJ 135-145
EMB EJet 170-190
Dornier 328JET (literally a Do328 with the prop nacelles replaced with pylons for hanging jets)

A version of the BAe146, the AvroRJet, is still made but I don’t know if it’s in use stateside.

When we expand “regional airline” to include any small capacity, limited-route-system airline, e.g. the late Midwest, or Spirit, my planespotting/reading has included 737 (various series), MD80/90/95, A319/320 and EJet190.
Just so happens, the rise of the RJs resulted in a drying up of the market for, and a displacement from US routes of, many just fine late-generation props, and now with the rise in fuel costs some carriers are looking to props again only to discover that production capacity and competition is way down.

Former airline type here. JRD nailed it.

In industry parlance, “Regional Jet” or “RJ” refers to size, not range. The major carriers’ union contracts require all jets bigger than size X to be flown by the main airline. Only jets smaller than X may be subcontracted out to afffiliates (at grossly lower wages & working conditions). So the manufacturers supply jets in sizes up to just below X for the affiliates to operate.

The value of X varies a bit from major to major, and there are frequently tiered rules: e.g. so many 50-seaters, and so many 70 seaters, none bigger than 71 seats, etc.

A318, 737, & DC9/MD80/717 are all mainline size; they are not RJs in anybody’s book.

The latest EMB EJets are pushing very hard against the ceiling, and could be offered in versions above the limit if any airline really wanted to take on the labor battle.

As technology marches on, the range of these small jets keeps growing; there is nothing “regional” about their coverage of the US marketplace.

The actual economics of the RJs are not as good as the big jets for the same passenger load; it’s union-busting pure & simple. But it has been very effective.

Incorrect terminology on my part.

I was thinking not only of smaller airlines, such as Horizon; but also Alaska Airlines, which I erroneously thought only served the western regions of the U.S., Canada and Mexico. Upon further reading I see they also go to Boston, Miami, Orlando, Newark, Arlington (VA), Chicago, and the District of Columbia. So it serves more places than I was thinking of for the purposes of the OP.

Just about the one old-school “region” carrier of that sort left is Hawaiian, which is kind of unique due to the market it serves. ISTM, with deregulation and the elimination of “protected” routes, the old-style limited-region scheduled carriers such as Piedmont or Western were thrown into competition head-to-head with the major carriers, expanding neighbors, and start-ups such as SouthWest; those who could not find a good strategy to make it work on their own ended up dying or else buying or being bought up by other airlines; e.g. modern USAirways = (America West + [old USAirways = (PSA+Piedmont+Alleghany)]). Alaska, already a specialist in Pacific-NW-coast routes, expanded by selling itself as a desirable airline to use to get connections to the Pacific-NW-coast destinations from elsewhere.