It’ll soon be possible to take a flight from the state capital to the nation’s capital. Northwest Airline’s Thomas Becker says the carrier stepped in to offer airlink service after another airline dropped it last year. While it can be a battle to get a “gate” at a big airport, Becker explains a “slot” is even more elusive — because it’s a moment of time, at the nation’s busiest places. It’s a time frame you can land and take off in, he explains — and Washington’s Reagan National Airport, Chicago’s O’Hare and New York’s LaGuardia airports are the only places where an airline must have a “slot,” a document from the federal DOT that entitles their planes to land and take off at certain times …or if something’s thrown off all the schedules, at least land and take off a certain number of times per day. Unlike the carrier that gave up the Des Moines to Washington route last year, Becker says Northwest will use a smaller plane, a 44-seat regional jet that will make the route economically viable. Flights are set to begin two weeks from today, on March first, with Northwest airlink partner Pinnacle Airlines.