Frequent fliers are people who travel often by air, usually for business or leisure. The term can refer to passengers of commercial airlines, private JETS, supersonic transports (SSTs), and other forms of air travel. The crossword solutions for the term 'Frequent Fliers' are JETS (4 letters), SSTs (4 letters), and Jetset (6 letters). JETS are a type of aircraft used for commercial air travel, SSTs are supersonic transports, and Jetset is a term used to describe people who frequently fly on private JETS.