If current trends continue-and all indications point that way-both domestic and foreign airlines will soon offer passengers fewer frills than a Puri tan's parlor. "We got no ..." is rapidly becoming the draconian mantra of the airlines, as they systematically eliminate meals, first-class service and even tickets. Among carriers that have knocked out or drastically pared first class on longer flights are KLM Royal Dutch Airlines and Northwest Airlines, which have replaced first class with business class on trans-Atlantic flights. United Airlines is contemplating a similar move, though VP-Advertising and Promotion John Ruhaak said no decision has been made. He added that the pool of first-class passengers is dwindling because companies are keeping an ever-tighter rein on costs. USAir and Continental Airlines have ceased meal service on many flights; Continental has seat pocket cards saying, "Save now. Eat later." Details on Page 52.