The Lockheed Martin F-35 Joint Strike Fighter programme is likely to grow beyond 10 countries, with requests for proposals expected this year, while the US Marine Corps will look at the F-35B's handling aboard ships.
US Navy Vice Adm David Venlet, programme executive officer of the JSF programme office, says he is "reluctant to speculate" as to the identity of the potential newcomers, but expects "RFP activity in the near months".
"I'll leave it to those nations to make their announcements and revelations," says Venlet, who has been with the F-35 programme for nine months. "We have nine partners and expect this to grow."
Venlet was speaking at a media conference in Melbourne before Australia's Avalon 2011 air show. The nation is already a partner in the programme, with the Royal Australian Air Force planning to purchase up to 100 F-35s to replace its Boeing F/A-18 Hornets. These were acquired in the late 1980s and are not expected to serve beyond 2020.
Possible new candidates in the Asia-Pacific region could include Japan, which is interested in acquiring a fifth-generation capability following its failure to acquire the Lockheed F-22 Raptor from the USA.
Venlet also spoke of how the troubled F-35B short take-off and vertical landing variant will be assessed during its two-year probation period. In January Washington restructured the F-35 programme, effectively decoupling the F-35B from the other variants - the conventional take-off and landing F-35A (the variant for the US Air Force that the RAAF will also use) and the F-35C carrier variant.
The USMC will focus mainly on the availability aspects of the F-35B, says Venlet, and getting the type to the point where it is capable of unmonitored flight clearance, or operating autonomously without a ground station monitoring aircraft performance.
The Marines will also look at its handling characteristics aboard amphibious vessels, including flight operations as well as maintaining and supporting the aircraft at sea.
"The Marines are focused on meeting development results and key performance parameters," says Venlet. "These will also be assessed against the F-35B's cost to own and operate."
In regard to the other variants, Venlet feels the Pentagon has a "realistic plan" for both flight sciences and operational testing.
"In flight sciences testing we have decoupled the three variants, so no one aircraft slows down any of the others," he says. "Each service chief will see the flight sciences developed at the best possible pace for the respective variant. What is not decoupled are mission systems: radar, other sensors and datalinks - which are common across all three variants."
As for initial operating capability (IOC), Venlet says that this is up to the individual service chiefs.
"Our IOC will be at the end of 2018," says Air Vice Marshal Kym Osley, who represents the RAAF in the programme. "Approximately 18 months before this we anticipate the USAF IOC in 2016. End-2018 is the date we've always planned for." The gap is required mainly due to testing and certification activities specific to Australia.