Getting your Trinity Audio player ready...

The passenger terminal at Quincy Municipal Airport could almost serve as a stand-in for the set of television’s “Wings.”

The building has two lonely ticket counters-one for each of the regional airlines that serve the Quincy/Hannibal, Mo., area.

But the small turboprops the carriers operate link business and leisure travelers from the area with major airlines in St. Louis and Chicago.

Those links are becoming increasingly important as the bigger carriers seek to cut costs by eliminating jet service in many small-city markets.

Trans States Airlines, which operates as a feeder for Trans World Airlines at Lambert Field in St. Louis, has taken over some jet routes from its partner and is providing supplementary turboprop flights on others.

“There’s a lot of replacement service going on today,” said Bill Mishk, marketing director for the St. Louis-based regional airline, which flies under the name Trans World Express.

More than 50 million passengers traveled on regional airlines last year.

Turboprop service has replaced jet service on 375 routes in the last five years, according to analysts at Kidder, Peabody & Co. in New York. But airlines have introduced jet service on 202 other routes, for a net loss of service on 173 routes.

Trans World Express’ route system now stretches as far south as Birmingham, Ala., and as far north as Madison, Wis., and includes Chicago’s Midway Airport.

Most of the cities connected by regional airlines to St. Louis and Chicago never had jet flights.

Many others that have lost some or all of their jet flights are actually getting better service, because the regionals can offer more daily departures with their smaller aircraft.

The number of people flying the nation’s 130 regional airlines has doubled in the last decade.

The carriers posted much of that growth in just the last three years.

That growth has been assisted by government subsidies to some of the small airlines for providing flights from certain small cities under the federal Essential Air Service program.

As the regional airlines have become bigger, so has the size of the aircraft they operate.

Some of the turboprop aircraft in U.S. fleets carry nearly 70 passengers, as well as flight attendants.

Comair Inc., which operates as Delta Connection at Lambert Field and also serves Midway Airport, has started to operate a 50-passenger Canadair regional jet between St. Louis and its base in Cincinnati.

The airline has 16 of the jets in its fleet and plans to increase that number, said Gloria Weber, communications director.

“It’s enabled us to expand our geographic territory,” Weber said.

Comair now offers jet service in such far-flung cities as Omaha; Des Moines; Newark, N.J.; Providence, R.I.; and Portland, Maine.

Comair’s jets are more than 50 percent faster than its turboprops and have a range that is roughly three times greater, Weber said.

Although vacationers from small cities use the regional airlines to connect with major carriers, the operations are geared more toward business travelers.

People who need to travel to close a crucial deal are less likely to be concerned about price than people who are flying for fun, Weber said.

Because most regional airlines attract a greater percentage of high-paying business travelers than the major airlines, they can fly half-full planes and still make money.