Boeing 747-400 Global Supertanker 🔥✈️ The largest firefighting aircraft ever to operate. Converted from a 747-400, the Global Supertanker could drop 19,600 gallons (163,503 lbs) of fire retardant or water in a single pass, nearly 10x more than a typical air tanker. Operated by Global Supertanker Services (GTS), it entered service in 2016 and flew missions across the United States, Chile, Israel, and Bolivia, responding to some of the largest wildfires on Earth. Cruise speed: 560 mph Drop speed: