Federally mediated talks aimed at resolving the dispute over wages and flights by nonunion pilots started this afternoon.

With only five days left in a mandated cooling-off period, the Allied Pilots Association and AMR Corp., parent company of American Airlines, were scheduled to take their dispute before the National Mediation Board this afternoon.

They have until 12:01 a.m. EST Saturday to reach agreement or the 9,300 pilots promise to walk out, grounding the airline during the busy Presidents Day weekend. American offers more domestic flights than any other U.S. airline, and carries 200,000 passengers a day on national and international flights.

(In Hawaii, American runs five daily round-trip Honolulu flights - two from Dallas and one each from Chicago, Los Angeles and San Francisco - a daily Los Angeles-Maui round trip, and a daily Honolulu-Maui round trip.)

After meeting last week with American President Donald Carty and other top airline managers, union President Jim Sovich said a strike is "more likely than not." The union has created a "war room" to keep track of pilots this week to inform them if a strike is called and help them if they become stranded.

The airline also is preparing, including sending notices to its 90,000 employees that they could be laid off soon. To pay the bills in case a strike ends flight operations, American has borrowed $1 billion from an existing credit line and has pledged its fleet as collateral for another $1 billion in credit. The funds are in addition to more than $1 billion the airline has on hand.

The money would support the company through a three-month strike, based on AMR projections showing that for each 30 days of a strike the company would lose $1 billion, or all of 1996's profits.

The pilots have not had a basic wage increase since their contract became amendable in 1993. They are seeking raises of about 11 percent over four years, plus increased stock options.