The Federal Aviation Administration has given the Martha’s Vineyard Airport Commission a deadline of Dec. 31 to finish designing an aircraft rescue and firefighting facility that is already years behind schedule.

Attorneys for the Martha’s Vineyard Airport Commission and embattled airport manager Sean Flynn met this week in Boston in an effort to negotiate the terms of Mr. Flynn’s exit.

Martha’s Vineyard Airport manager Sean Flynn is leaving his job, the chairman of airport commission said Thursday, capping months of tension over operational issues and workplace disputes. “We’re negotiating an amicable separation,” commission chairman Myron Garfinkle told the Gazette.

For the second year in a row, legal spending is sharply up at the Martha’s Vineyard Airport, due largely to the recently-concluded lawsuit with the county over control and authority at the airport.

A superior court judge Monday handed a victory to the Martha’s Vineyard Airport Commission, ending a costly protracted legal battle with the Dukes County Commission over control of the Island’s only commercial airport.

The embattled Martha’s Vineyard Airport Commission met briefly this week to elect new officers and set a short-term agenda which includes a review of financial affairs at the Island’s only commercial airport.

At a special meeting marked by bitter acrimony Thursday, county commissioners recast their controversial votes from last month when they ousted two airport commissioners and appointed three new ones.

The Martha’s Vineyard Airport Commission is in a state of limbo amid a dispute over authority to call a meeting and uncertainty about the recent seating of three new commissioners.