Development started after the 2002 fire season, which saw the fatal crashes of two airtankers in the USA. The accidents, involving a Lockheed C-130A Hercules and a Consolidated PB4Y-2, prompted the U.S. Department of Interior to issue an official Request for Information on next-generation airtankers.Evergreen proposed to convert up to four of its Boeing 747-200 Freighters into massive 'Supertankers'.The first converted Boeing 747 (N470EV) made its maiden flight on February 19, 2004.The current Supertanker is N479EV, a 747-100. By June 2006, Evergreen had spent $40 million on the project and was hopeful of both FAA certification, and an evaluation contract from the US Forest Service
An issue that impacted usage by the Forest Service was the USFS requirement for using fire retardant rather than water. When Evergreen attempted to convert the system from water dispensing to retardant, they encountered objections from the FAA. The FAA's issue related to the much greater density of fire retardant and the corresponding increased stress on the airframe thus delaying the FAA certification. The FAA determined that the Supertanker's service life would be much less and raised concerns about dangers of stress during firefighting operations and heavy weight maneuvering.Pesawat Pemadam Kebakaran Terbesar Di Dunia Evergreen Supertanker, Evergreen Supertanker, Pesawat Pemadam Kebakaran Terbesar Di Dunia ini dibuat dari Boeing 747. Evergreen memiliki ruang untuk tangki hingga 24.000 galon. dan dapat mematikan 105.000 hectar kebakaran. Evergreen Supertanker, Pesawat Pemadam Kebakaran Terbesar Di Dunia ini dibuat dari Boeing 747. Evergreen memiliki ruang untuk tangki hingga 24.000 galon. dan dapat mematikan 105.000 hectar kebakaran...