A labor dispute over job pay and security could threaten the airline that serves many of the smaller airports in the region. Mesaba and its pilots union started three days of negotiation today in Minneapolis. They have yet to agree on a contract after two-and-a-half years of talks. Mesaba operates connecting flights from hubs to smaller cities around the Midwest and the South for Northwest Airlines. Mesaba pilots voted overwhelmingly this fall to authorize a strike if necessary. To show they're prepared, today the union offered a first look at its strike operations center. On the 10th floor of an office building, overlooking Minneapolis-St. Paul International Airport, off-duty pilots watched a bank of five computer screens. Strike operations manager Mike Dockman says they can monitor air traffic all over the country.