The F-35 short takeoff and vertical landing (STOLV) variant will make its international debut in July at the Royal International Air Tattoo (RIAT) and will also fly at the Farnborough International Air Show, according to the British Ministry of Defence (MoD).

RIAT is open to the public July 11-13 while Farnborough is open to trade visitors July 14-18 and the public July 19-20. Both RIAT and Farnborough are major international aviation shows, with RIAT calling itself the world’s largest airshow. Farnborough is hosted biennially.

The Marine Corps’ F-35B short takeoff and vertical landing (STOVL) variant. Photo: Lockheed Martin.

The United Kingdom is purchasing the STOVL F-35 variant, which the MOD said is scheduled to transition to U.K. hands in 2018. The MoD has three aircraft, all currently based in the United States, undertaking training with Royal Navy and Royal Air Force pilots. Orders for further aircraft will be placed over the next few years.

The Government Accountability Office (GAO) said in March delays in software development and testing may delay the F-35 STOVL variant, called the F-35B in the United States, from reaching initial operational capability (IOC) in July 2015. Software has been a significant challenge for the program.

Along with the United States and United Kingdom, Australia, Canada, Denmark, Italy, the Netherlands, Norway and Turkey are partner countries in the F-35 program. South Korea is also purchasing the F-35, which is developed by Lockheed Martin [LMT] with subcontractors Northrop Grumman [NOC] and BAE Systems.