WASHINGTON The United States and its allies plan to buy more than 3,100 new F-35 Joint Strike Fighter warplanes in coming years.
Following is a list of the planned purchases and possible changes, where applicable, according to data provided by Lockheed Martin Corp, the prime contractor for the $396 billion weapons program, and defense officials in the United States and other purchasing countries.
Lockheed is developing three variations for the U.S. military services and eight partner countries that helped fund the plane's development - Britain, Australia, Italy, Turkey, the Netherlands, Denmark, Norway and Canada. Two other countries, Israel and Japan, have also placed orders for the fighter jet.
The conventional landing A-model will be used by the U.S. Air Force and most allies; the B-model, which can take off from shorter runways and land like a helicopter, will be used by the U.S. Marine Corps, Italy and Britain; and the C-model, or carrier variant, will be used by the U.S. Navy and Marine Corps.
U.S. AIR FORCE
The U.S. Air Force plans to buy a total of 1,763 F-35 A-models through 2037. The Air Force has already begun early training of pilots to fly the F-35, and technicians to service the planes, at Eglin Air Force Base in Florida.
The first F-35As have begun to arrive at Nellis Air Force Base near Las Vegas, where the Air Force eventually plans to use 36 F-35s for operational testing and evaluation and training.
Current plans call for the U.S. Navy to buy 260 C-model F-35s, which have longer wings and a special tailhook that allows them to land on aircraft carriers. Navy officials are evaluating how many F-35 C-models to buy - and on what timetable - since lawmakers have also ordered the Navy to buy 41 new F/A-18 E/F Super Hornets built by Boeing Co at a cost of about $3.1 billion.
U.S. MARINE CORPS
The Marine Corps, the smallest of the U.S. military branches plans to buy 340 F-35 B-models and 80 F-35 C-models to replace its current fleet of F/A-18 Hornets, EA-6B Prowlers, and AV-8B Harrier "jump jets."
The Marines aim to start using the new F-35Bs by the end of 2015, if Lockheed completes development of the software it is now working on.
Britain's Royal Air Force and Royal Navy, which have invested $2 billion to help develop the new warplane, plan to buy a total of 138 F-35 B-models.
Britain has so far committed to buying 48 of the new planes, and remains committed to the F-35 program, but its defense budget remains under pressure.
Italy initially planned to buy 131 F-35 fighters, but curtailed its order early last year. Now it is slated to buy 60 F-35A models and 30 F-35Bs, but tough budget pressures in Europe and an inconclusive election could still pare that 90-jet order in coming years, experts say.
Italy has invested heavily in both the F-35 development effort and construction of a final assembly plant being built by Lockheed Martin and Alenia Aeronautica, a unit of Finmeccanica SpA at Cameri air base in northern Italy.
The Dutch military, which is slated to buy 85 F-35As in coming years, has already ordered two jets that will be used for training. A spokesman for the Dutch defense ministry said the government will finalize its procurement plans for the F-35 this year.
Turkey is slated to buy 100 F-35As. It recently delayed by two years its first order for two jets.
Australia is slated to buy 100 F-35As, but experts say it could reduce its order by 30 to 50 jets, given delays in the expected fielding of the new plane. It is expected to decide later this year whether to buy 24 more Boeing Co F/A-18 E/F Super Hornets.
Norway, which has a growing defense budget unlike many of its European neighbors, plans to buy 52 F-35A fighter jets at a total projected cost of $10 billion, the country's biggest weapons procurement.
Denmark is slated to buy 30 F-35As.
Canada, one of the eight international development partners on the F-35 program, was to buy 65 F-35 A-model fighter jets for C$9 billion, but announced in December that it would evaluate all available options for new fighters.
The announcement was intended to put an end to growing controversy about the government's decision to buy the F-35 without an open competition. A spending watchdog said the decision to buy the F-35s was based on bad data from officials, who deliberately downplayed the costs and risks of the program.
Canada has not formally withdrawn from the F-35 program, and still has a representative at the program's offices near the Pentagon.
Israel has ordered 19 F-35 jets, and plans to order up to 75 jets in coming years.
Japan announced in December 2011 that it was ordering 42 F-35 A-model jets.
A senior official at Japan's Defense Ministry said it was keeping a close eye on cost and schedule risks on the program, but there were no plans to change Tokyo's order.
(Reporting By Andrea Shalal-Esa; Additional reporting by Ivana Sekularac in Amsterdam and Kiyoshi Takenaka in Tokyo)