By The Herald Editorial Board

Alaska, United and Southwest are not cleared for takeoff at Paine Field.

Not just yet, and maybe not for as long as 18 months.

The Federal Aviation Administration last week announced it was launching a new environmental assessment, a supplement to the assessment it made in 2012 that had assumed the operation of up to 12 flights a day — 12 takeoffs and 12 landings — at the Snohomish County-operated airport in Everett.

Since that review one of the initial airlines that had proposed offering commercial flights dropped out and was replaced by two others. Combined, the three airlines are planning a total of 24 flights each day from the general purpose airport, adding a new option for business and other travelers who now choose between Seattle-Tacoma International Airport — with a traffic-choked I-5 to slog through — and Bellingham International, about an hour north of Everett.

It’s an announcement that will disappoint supporters of commercial flights at Paine Field, who view that service as a needed boost to the county’s economic strength. Propeller Airports, which is building and will operate the terminal is, itself, part of that economic boost. It moved its headquarters from New York to Everett, and secured a 50-year lease for 11 acres of airport property, bringing $429,000 annually to the county in lease payments, plus a share of flight and parking revenue.

At the same time, the FAA’s decision gives a community group and Mukilteo city officials a second opportunity to voice their opposition to the daily commercial flights.

With a doubling of anticipated flights since 2012, it’s a review that should go forward now to avoid potential legal challenges in the future and to give full confidence to Paine Field neighbors and the larger community that possible impacts have been examined and addressed.

As of January, the two-gate terminal now being completed by Propeller maxed itself out with the addition of Southwest Airlines, which is seeking to offer five daily flights using Boeing 737s with 143 to 175 seats. That’s in addition to United Airline’s plans to offer six daily flights on 76-seat Embraer E175 jets and 13 daily flights on Embraer jets from Alaska Air’s partner, Horizon.

Propeller expects to serve about 1,700 departing passengers daily, a significant increase from the 1,000 passengers studied in the 2012 review.

Supplemental reviews by the FAA typically take between six and 18 months, including a 30-day public comment period prior to a final determination by the federal agency. The FAA could find that additional review isn’t necessary or that a new — and even lengthier — environmental review of noise, traffic and other impacts is required.

At its quickest, the review would mean the airlines couldn’t begin operations until the end of the year. The terminal, on which Propeller is spending about $40 million to build, is expected to be complete by September. A longer review will mean a frustrating wait as the terminal sits empty, whether that’s during a long, gray winter when warmer southern destinations are calling or when opportunities to land new businesses and jobs fly overhead to other new homes.

But both supporters and opponents can use that time best to continue their discussions, rather than re-litigate old arguments and force further delays.

When the state Supreme Court declined last year to hear an appeal by Mukilteo officials and Save Our Communities regarding approval for the terminal, Mukilteo Mayor Jennifer Gregerson said the city would focus on working with Propeller and the airlines to mitigate noise and traffic impacts.

Mukilteo and Paine Field neighbors can continue to hold Propeller and the airlines to their earlier commitments to a “fly friendly” program that works to set flight paths, hours of operation and other practices that limit noise and other impacts. The FAA’s review can then serve as an accurate baseline on which to evaluate those planned mitigations.

With ground transportation between Everett and Sea-Tac increasingly choked — and light-rail service between Everett and Sea-Tac not arriving for another 20 years — Snohomish County must be able to provide a link by air to Seattle, the West Coast and other destinations. But the airlines, which will have exclusive access to the passenger market here, need to be good neighbors.