The Joint Strike Fighter (JSF) is a joint, multinational acquisition program for the United States Air Force (USAF), Navy, Marine Corps and eight cooperative international partners. It was created to replace various aircraft while keeping development, production and operating costs down. The objective is to develop a technically superior and affordable fleet of aircraft that would be capable of a wide range of missions in a variety of theaters. The F-35 Lightning II, which is descended from the X-35, has become synonymous with the JSF program. I

The JSF program's hallmark of affordability is achieved through a high degree of commonality among its three variants: conventional takeoff and landing (CTOL), short takeoff and vertical landing (STOVL), and carrier-based. The CTOL variant is designated F-35A, and the first aircraft rolled off the assembly line on February 19, 2006. After undergoing extensive ground testing, it completed its maiden flight on December 15, 2006.

The F-35A is the smallest, lightest version and is the only one equipped with an internal gun. It is intended to replace the F-16 Fighting Falcons and A-10 Thunderbolts of the Air Force beginning in 2011. The F-35A matches or exceeds F-16 performance levels and goes beyond with increased range on internal fuel and advanced avionics. As a result, operational effectiveness, supportability, and survivability are greatly enhanced. Unlike the F-16, the aircraft is stealthy, enabling first-look, first-shot capability. It is equipped with internal laser designators and infrared sensors as well.

As of 2004, requirements called for 1,763 F-35As, making it the most-produced variant. The Air Force is tentatively scheduled to receive its first aircraft in 2008, but initial operational capability for the service is set for 2011. The Lightning II is expected to be the world's premier strike aircraft through 2040. It will provide air-to-air capability second only to the F-22 Raptor.