Jon Stout stood on a low mound last week and looked down the soon-to-be lengthened main runway at the Charles M. Schulz-Sonoma County Airport.

An Alaska Airlines twin-prop Bombardier Q400, the 4 p.m. from Portland, swooped out of the sky and glided in for an on-time arrival.

Stout, the airport manager, expects to have a busy 2014 leading the airport through its biggest expansion since World War II and attracting new commercial service to destinations east of California.

So far, this graded dirt mound and some new signs along the runway are the only evidence of a $53.8 million runway expansion project that broke ground in August. Construction, which is shut down for the winter, will resume in earnest in April with a flurry of work to extend both runways and divert an adjacent creek.

Stout said the project will be completed 10 months from now. Passengers on Alaska Airlines, currently the only airline serving Sonoma County with flights to Seattle, Portland, Los Angeles and San Diego, won't likely notice the construction.

"We should still be on track to be done by Nov. 1," Stout said. "We've developed a construction schedule to have no impact on commercial traffic."

The Federal Aviation Administration, which is funding 90 percent of the project, mandated that the airport decouple the ends of both runways so that they cross instead of forming a "V" shape. The project will also add new taxiways and safety improvements, which pilots will appreciate.

But the main benefit for the majority of North Coast travelers is the extra 885 feet of pavement on the main runway that will extend it to 6,000 feet, the key length for attracting regional jet service, Stout said.

"The interest from airlines definitely went up once we broke ground," Stout said.

In October, Stout met with a number of airline executives about adding service to Sonoma County. The most promising developments include a future United Airlines flight to Denver, which is a major hub for east coast connections, and American Airlines service to Phoenix, Stout said. Neither airlines have made commitments, though, he said.

Stout hopes to sign a letter of intent with an airline by June in order to take advantage of a $650,000 Department of Transportation grant to offset the airline's cost of starting new service.

Eastbound flights could start in the spring of 2015, Stout said, giving North Coast travelers a convenient alternative to San Francisco and Oakland airports.

Caltrans should finish widening the Airport Boulevard-Highway 101 interchange this year, and Sonoma-Marin Area Rail Transit commuter trains could serve a station near the airport in 2016. Both projects will help attract passengers, Stout said.

The airport's traffic reached an all-time high in 2012 with 213,917 passengers and was expected to exceed that in 2013 -#8212; 210,000 passengers had used the airport through November -#8212; with five daily Alaska flights. A new service could increase the total to up to 12 flights per day, Stout said.

The airport's long-term plan calls for 21 daily commercial flights. Stout said he has been in talks with other airlines about adding service in the next two to three years, including Allegiant Air to Las Vegas and Alaska Airlines to Maui.

Viva Aerobus, a budget Mexican airline, is exploring direct service from Sonoma County to Guadalajara, Mexico, the third most popular destination for North Bay travelers, Stout said. That would involve contracting Customs and Border Protection agents from San Francisco International Airport a few times per week.

"Are we underserved? Yes," Stout said. "But we're not going to have 50 flights a day. We're not going to be a San Jose or an Orange County."

More flights in and out of Sonoma County would be a boon for regional business and tourism, officials say.

Agilent Technologies, Medtronic and American AgCredit, a few of the large locally-based companies whose employees take frequent business trips, say they would benefit from additional air travel choices, according to Jonathan Coe, president of the Santa Rosa Chamber of Commerce.

The chamber has surveyed its members about expanded air service in an effort to help entice an airline to open routes to Sonoma County, Coe said. Now that the runway expansion project is underway, that is closer to becoming a reality, he said.

"Expanded service was theoretical until the dirt started flying," he said. "The dirt is now flying. It's time to say, 'Hey guys, who's going to be the first one in?'"

(You can reach Staff Writer Matt Brown at 521-5206 or matt.brown@pressdemocrat.com.)