FANS (Future Air Navigation System)
FANS is a set of datalink technologies, principally controller-pilot datalink communications and automatic dependent surveillance, that let aircraft exchange text messages and position reports with air traffic control by satellite instead of voice on HF radio. FANS 1/A equipment is required to fly in the most efficient North Atlantic tracks and increasingly in Pacific and Asian oceanic airspace. Aircraft without it are routed onto less direct tracks or lower altitudes, which can add 20–40 minutes and fuel to a transatlantic flight. Most business jets built after about 2012 have it; older aircraft may have been retrofitted, at a cost that buyers should factor in.