| 747 Supertanker | |
|---|---|
 | |
| Global 747-400 Supertanker, N744ST | |
| Role | Aerial firefighting Type of aircraft |
| National origin | United States |
| Manufacturer | Boeing |
| Designer | Evergreen International Aviation |
| First flight | 2006 |
| Introduction | 2009 |
| Retired | 2021 |
| Status | N744ST Converted into a freighter and sold toNational Airlines |
| Primary users | Global SuperTanker Services Evergreen International Aviation(former) |
| Number built | 3 |
| Developed from | Boeing 747 |
The747 Supertanker is a retiredaerial firefighting airtanker derived from variousBoeing 747 models. The aircraft is rated to carry up to 19,600 US gallons (74,000 L) offire retardant orwater. It is the largest aerial firefighting aircraft in the world.[1]
Initially developed byEvergreen International Aviation, the first Supertanker was based on a747-200 (N470EV, tanker/tail number 947), but never entered service. The second Supertanker (N479EV, tanker/tail number 979) was based on a747-100 originally manufactured by Boeing in 1971 forDelta Air Lines.[2] It entered service for the first time in 2009, fighting a fire inCuenca, Spain, and made its first American operation on August 31, 2009 at theOak Glen Fire in California. It is no longer in service.[3][4][5]
The third 747 Supertanker was developed by Global Supertanker Services, which acquired most of Evergreen's assets. The Global Supertanker (N744ST, tanker/tail number 944) is a Boeing 747-400 dubbed the Spirit ofJohn Muir. It was certified for firefighting flights by the Federal Aviation Administration in September 2016 and fought fires in Chile and Israel before being contracted by U.S. officials to fight California wildfires in 2017.[6] It also took part in firefighting in Bolivia in August 2019. It was sold to National Airlines and converted back to a cargo configuration in 2021.[citation needed]
Development started after the 2002 fire season, which saw thefatal crashes of two air tankers in the United States. The accidents, involving aLockheed C-130 Hercules and aConsolidated PB4Y-2 Privateer, prompted theUS Department of Interior to issue an officialrequest for information on next-generation airtankers.[7]
Evergreen proposed to convert up to four of its Boeing 747-200 Freighters into Supertankers. The first converted Boeing 747 (N470EV) made its maiden flight on February 19, 2004.[7]
By June 2006, Evergreen had spent $40 million on the project and was waiting for bothUS Federal Aviation Administration (FAA) certification and an evaluation contract from theUS Forest Service.[8] In October 2006 the FAA issued Evergreen a supplementary type certificate for the "installation and removal" of internal tanks, associated systems and the support structure for the aerial dispersal of liquids.[9]
The Global Supertanker was equipped with a pressurized liquid drop system, which could dispersefire retardant under high pressure or drop retardant at the speed of falling rain.[10] Using the pressurized system, the aircraft could deliver retardant to the scene of a fire while flying at a height of 400 to 800 feet (120–240 m), at approximately 160 mph (260 km/h; 140 kn), configured as if it were on approach for landing. The Supertanker's tank system could be configured for segmented drops, allowing the contents of the tank to be released at multiple intervals while in flight.[10] According to the company, the aircraft was capable of laying down a swath of fire retardant 3 mi (4.8 km) long and as wide as 150 ft (46 m).[11]
A top speed of nearly 600 mph (970 km/h; 520 kn) allowed it to be almost anywhere in the U.S. in approximately 5 hours and reach most of the world in under 20 hours.[12]
The Supertanker can operate from any airport with an 8,000-foot (2,400 m) long runway and suitable facilities.[10] In late 2009, the aircraft was under a call-when-needed (CWN) contract withCalifornia Department of Forestry and Fire Protection (Cal Fire) and was stationed atSacramento McClellan Airport outside ofSacramento,California.[11]
Regulations allow for five individuals that are not crewmembers to be carried in the upper deck. This area could be used for command and control, mapping, incident monitoring and video/communications operations.[13]
In December 2010, the Supertanker was deployed to Israel to fight the2010 Mount Carmel forest fire. This was carried out along with crew and utilities donated by other international fire agencies.[14] On June 9, 2011 the Supertanker was also deployed to fight theWallow Fire in the US state of Arizona which was at 607 square miles (1,570 km2) burned and uncontained at the time.[15]
Since May 2016, Global SuperTanker has been based in Colorado at theColorado Springs Airport, chosen in part for its convenient location for quick deployment to the western US and necessary infrastructure for the large and heavy aircraft.[16] Just a few weeks later, the company was awarded a one-year contract from nearbyDouglas County to assist with wildfire containment.[17][18]
In November 2016, the newer N744ST 747-400 Global Supertanker was deployed to Israel to help fight the wildfires raging in the northern port city of Haifa and elsewhere throughout the country.[19]
In January 2017, the Global Supertanker was deployed toSantiago,Chile, to help the local authorities to combat one of the biggest series of wildfires in the country's history. The wildfires in the south of the country, at the time of the arrival of the 747-400, had burnt more than 494,000 acres (200,000 ha) of forests and hundreds of houses. The operation of the aircraft was the initiative of philanthropist Lucy Avilés and her husband Benjamin Walton, who funded the costs.[20]
In September 2017, the Supertanker was contracted by Cal Fire.[21] In December 2017, the plane was leased by Cal Fire during thelate-2017 wildfire season with most drops over theThomas Fire.[22]
In July 2018, the Colorado Division of Fire Prevention and Control signed a CWN contract to use the supertanker over US Forest Service lands.[23] This followed media inquiries earlier in the summer as to why the supertanker wasn't contracted to fight the fires burning in its home state.[24][25][26]
In November 2018, the Global SuperTanker was deployed to northern California to assist with the out-of-control Camp Fire[27] in Butte County.[28][29][30]
On June 14, 2013, the Supertanker received a call-when-needed contract from theUnited States Forest Service, despite not being operational. The aircraft was sitting without engines at theboneyard and maintenance facility atPinal Airpark outsideMarana, Arizona, in need of a“C” check and other maintenance, which would cost US$1 million. Evergreen deferred the maintenance because of financial difficulties, planning to have the Supertanker ready in time for the 2014 fire season.[31]
On November 30, 2013, Evergreen effectively shut down operations.[32] In December 2013, Marana Aerospace Solutions proceeded with the sale of the Supertanker, in lieu of rent and other payments that Evergreen had failed to make. An involuntarybankruptcy case was filed against Evergreen later in the month, and then Evergreen itself filed for dissolution underChapter 7 bankruptcy on December 31, 2013, freezing the sale.[33]
On December 31, 2013, Evergreen International Airlines filed a Chapter 7 petition with the US Bankruptcy Court inDelaware with substantially all assets (including all 747 airframes) subsequently sold to a parts salvage re-seller, Jet Midwest Aviation. On July 12, 2017, tail number 979 was intentionally destroyed for salvage atPinal Airpark, in Marana, Arizona.
In August 2015, Global SuperTanker Services (the successor to the defunct Evergreen Supertanker Services), purchased all the physical assets and intellectual property related to Evergreen's original Supertanker (except the 747-100 airframe itself) from Jet Midwest. They transplanted the existing sprayer tank system from the 747-100 into the newerBoeing 747-400 (N744ST) airframe.[1][34][35]
In 2021, Global SuperTanker Services began facing financial difficulties, and in April 2021, the company shut down. They sold the Supertanker toNational Airlines to be converted into a cargo aircraft.[36][37][38]
