According to Wiki (reasonably credible on topics like this . . . ):
It is worth adding a bit on the Israeli version:
The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, all-weather stealth multirole fighters undergoing testing and final development by the United States. The fifth generation combat aircraft is designed to perform ground attack, aerial reconnaissance, and air defense missions. The F-35 has three main models: the F-35A conventional takeoff and landing (CTOL) variant, the F-35B short take-off and vertical-landing (STOVL) variant, and the F-35C carrier-based Catapult Assisted Take-Off But Arrested Recovery (CATOBAR) variant.
F35 in flight
The F-35 is descended from the X-35, which was the winning design of the Joint Strike Fighter (JSF) program. It is being designed and built by an aerospace industry team led by Lockheed Martin. Other major F-35 industry partners include Northrop Grumman, Pratt & Whitney and BAE Systems. The F-35 took its first flight on 15 December 2006. The United States plans to buy 2,457 aircraft. The F-35 variants are intended to provide the bulk of the manned tactical airpower of the U.S. Air Force, Navy, and Marine Corps over the coming decades. Deliveries of the F-35 for the U.S. military are scheduled to be completed in 2037.
The F-35I is an F-35A with Israeli modifications. A senior Israel Air Force official stated "the aircraft will be designated F-35I, as there will be unique Israeli features installed in them". Despite an initial refusal to allow such modifications, the U.S. has agreed to let Israel integrate its own electronic warfare systems, such as sensors and countermeasures, into the aircraft. The main computer will have a plug-and-play feature to allow add-on Israeli electronics to be used; proposed systems include an external jamming pod, and new air-to-air missiles and guided bombs in the internal weapon bays. Israeli pilots are scheduled to start F-35 training in December 2016 at Eglin AFB Florida with the first squadron activated about a year later.
Israel Aerospace Industries (IAI) has considered playing a role in the development of a proposed two-seat F-35; an IAI executive stated: "There is a known demand for two seats not only from Israel but from other air forces." IAI plans to produce conformal fuel tanks. A senior IAF official stated that elements of the F-35's stealth may be overcome in 5 to 10 years, while the aircraft will be in service for 30 to 40 years, which is why Israel insisted on installing their own electronic warfare systems: "The basic F-35 design is OK. We can make do with adding integrated software." Israel is interested in purchasing up to 75 F-35s.
An ongoing story. END