Viru Viru International Airport near Santa Cruz de la Sierra is Bolivia’s most important airport. From the end of last week a red and white jumbo jet is taking off up to four times a day from the 3.5-kilometer-long runway.

A “Global Supertanker”, the largest fire-fighting aircraft in the world and it is there at the request of the government of Bolivian President Evo Morales to help fight the fires in the Amazon savannah region of Chiquitania.

The home base of the converted Boeing 747-400 is in Sacramento, California and it is operated by Global SuperTanker Services.

“The Spirit of John Muir differs from other firefighting planes not just because it is capable of variable rate drops,” commented Jim Wheeler, President and CEO of Global SuperTanker Services when the four-engine aircraft was first converted.

“As the world’s largest aerial firefighting asset, the John Muir can fly 600 miles per hour for long ranges at efficient altitudes, reaching and combatting any fire in the Western U.S. in less than three hours.”

The aircraft bears the name “Spirit of John Muir” after the Scottish-American natural philosopher who, as one of the co-founders of the Sierra Club, brought nature conservation to the USA. On the tail fin, the white number “944” is emblazoned on a red background, an internal registration number of the operator.

The aircraft, which was first used as a passenger aircraft for Japan Airlines and later as a freighter for Evergreen International, is particularly unique because of what will be found in its interior: There are eight pressurized tanks that, combined, can hold up to 90,000 liters (20,000 gallons) of water or fire-retardant chemicals.

The liquids can be pumped out through four individual openings in the hull which can either be emptied simultaneously with great force or discharged more slowly to create artificial rain.