According to Official Guinness Records,
Global SuperTanker Services, founded in 2015, uses a converted Boeing 747-400 jumbo jet as an aerial firefighter. It is capable of carrying 74,200 litres of water or fire retardant a distance of 6,400 km. It is designed to drop its load onto wildfires from a height of just 120–240 m at around 260 km/h. The aircraft has a wingspan of 64 m and there is just one firefighting 747 in service globally.Evergreen went bust and have now reformed as GSS. The original jumbo was a 747-200 but GSS have now transferred the firefighting technology into the 747-400.
For a complete list of 2015 records, please visit 2015 Guinness Records in United States.