• American Airlines will launch new long-haul routes from LaGuardia. They only fly once a week.
• LaGuardia’s new routes are feasible because the “perimeter rule” is waived on Saturdays.
• American and other airlines also use exceptions to the perimeter rules in Washington, DC.

American Airlines will use a waiver next year to fly longer routes than normal from New York’s LaGuardia Airport.

An airline spokesperson confirmed to Business Insider on Monday that American will launch new flights to Bozeman and Kalispell in Montana and Calgary in Canada in June 2025 to target leisure travelers.

There is one restriction: the routes will only operate on Saturdays.

This is because LaGuardia allows flights of only 1,500 miles or less Sunday through Friday to manage airport capacity. This is called the “perimeter rule.” Longer flights and larger jets will primarily be relocated to the nearby Newark Liberty and John F. Kennedy airports.

However, the rule does not apply to flights to Denver at any time or to flights to any other location on Saturdays. The latter exception gave American the flexibility it needed to fly the new Saturday routes to Montana and Canada.

LaGurdia’s slot restriction is also waived on Saturdays, meaning American Airlines does not require special takeoff and landing permits for the routes. Cirium data shows all three flights will be on a Boeing 737 Max and will travel about 2,000 miles.

Operating flights only on Saturdays to get around the perimeter rule at LaGuardia is nothing new, although airlines have struggled to fill their planes because Saturdays are days of lower demand.

Delta Air Lines, for example, canceled two Saturday cross-country flights from LaGuardia to Los Angeles and Phoenix in January.

American also uses perimeter exceptions in the US capital

Ronald Reagan Washington National Airport in Washington, DC is the only other U.S. airport with a mandatory perimeter rule. The restrictions at both airports were introduced in the 1980s.

Reagan’s routes are limited to 1,250 miles. Dulles International Airport, about 30 miles away, offers longer flights.

However, over the past two decades, Congress has increased daily slot quotas to allow more flights outside the Perimeter on Sundays through Fridays.

American and other airlines have made use of the exemptions. Cirium shows that American already flies daily to Las Vegas, Los Angeles and Phoenix.

Alaska Airlines, Delta Air Lines, Frontier Airlines, Southwest Airlines and United Airlines also use exemptions to fly daily from Reagan to cities such as Los Angeles, San Francisco, Austin, Denver and Seattle.

The Federal Aviation Administration reauthorization bill signed in May authorized 10 additional slots that could operate within or outside Reagan’s radius. That’s the equivalent of five more round-trip flights.

American won one of the spots Friday, a daily round-trip to San Antonio starting in March. It will be the only airline operating the flight.

Meanwhile, Delta received a pair of slots to Seattle, Alaska one to San Diego, Southwest will use one to Las Vegas and United received approval to San Francisco – which will be the airline’s second daily flight to the California city.

There is a debate about keeping the perimeter rule at Reagan and LaGuardia.

Some advocates say it reduces airport noise and congestion and ensures airlines don’t shift slots to give up regional routes within the radius. A near-miss at Reagan in May also sparked concerns that more flights could compromise runway safety.

Opponents of the rule say it restricts the airline network, gives travelers less choice, increases airfares and limits economic growth. For lawmakers, repealing the Reagan rule would mean more convenient flights to D.C. from their home states.