One of the hardest things to figure out about cutting greenhouse gas emissions has been what to do about aviation, since most commercial jets are too heavy to fly under electric power with today’s technology. But United Airlines is beginning to provide a picture of how electric planes will be part of its future and a key to remaking the way travelers think about aviation as a choice for shorter distance routes.

The nation’s No. 3 carrier has a contract to buy electric 30-seat planes from startup Heart Aerospace, which Heart said it plans to introduce in 2028. In a twist, United’s plan is not to replace big jets, but to focus the new planes on regional service. The airline is also preparing to introduce eVTOL (electric vertical takeoff and landing) craft to do local transport like taking passengers from central cities to airports.

The idea is less to shift how fliers behave than to convince small-city residents who now drive on trips of 250 miles or less to take a plane instead, Mike Leskinen, United’s vice president of corporate development and president of its United Ventures investing arm, said at the CNBC ESG Impact earlier this month. If it works, it opens up a new market for carriers like United, especially outside major metropolitan areas.

“There’s absolutely a lot of hurdles to clear but…