As a result of a redesign to reduce the weight of the F-35B short take-off and vertical landing (STOVL) variant, AA-1 is a one-off and not fully representive of the production JSF. It is being used to validate design, manufacturing, assembly and test processes for the 14 development flight-test aircraft that will follow.
Powered by a Pratt & Whitney F135 engine, AA-1 is equipped with most of the vehicle systems planned for later F-35s, including the fly-by-wire/power-by-wire flight controls and flat-panel cockpit displays. The mission systems, incuding active-array radar and 360deg infrared sensors, will be tested in later aircraft.
Assembly of the next flight-test aircraft, the first optimised-airframe STOVL F-35B, is already under way at Lockheed and partners Northrop Grumman and BAE Systems, with the aircraft scheduled to fly in February 2008. The first optimised-airframe F-35A is to fly in August 2008 and the first F-35C carrier variant in Januray 2009.
AA-1 carries the flags of the eight international nations involved in development the JSF (pictured below): Australia, Canada, Denmark, Italy, the Netherlands, Norway, Turkey and the UK, which is the only Level 1 partner. Lockheed and the US government are hoping the eight nations will sign a memorandum of understanding on the JSF production, sustainment and follow-on development phase in December.
sa: http://www.flightglobal.com/Articles...+official.html