SEATTLE — Capt. Mike Adams demonstrated what the future will look like at the nation’s airports as he pulled back on the throttles of his Boeing 737 flight simulator, setting the engines on idle to glide smoothly from his cruising altitude all the way down to the runway.

Starting in June, that’s exactly what actual Alaska Airlines flights will be doing when the airline begins testing the use of satellite technology to land at Seattle-Tacoma International Airport — all in the hope of saving fuel and reducing delays.

Alaska Airlines, one of the nation’s smallest airlines, has taken some of the biggest steps in adopting a technology that allows its planes to navigate Alaska’s hazardous terrain, weaving through narrow valleys and mountain peaks, and land at remote airports in some of the worst imaginable weather. Now it wants to demonstrate that technology at big, busy airports, said Captain Adams, the airline’s chief technical pilot.

Planes using the new technology will cut 30 miles from their approach to the airport by taking a more direct path to the runway. They will no longer need to circle overhead awaiting clearance to land. And pilots will not have to push and pull at the throttles — in effect, repeatedly stepping on the gas, then coasting — to maintain the altitude assigned by air traffic controllers as they begin a stairlike descent. For passengers, landing will feel more like coming down a slide.