Representatives from the United States, Canada, Australia and the United Kingdom all approved an international memorandum of understanding solidifying the participation of those nations for the next stage of development on the fifth-generation aircraft.

The MOU is expected to lay out a set of principles that will formally articulate the international fighter effort’s production schedule. It also is expected to cover sustainment and follow-on development issues for the multibillion-dollar program, according to U.S. defense officials.

Perhaps more importantly, the MOU could dictate terms and an overall number of component and system transfers that would be granted to the U.S. allies participating in the F-35 program.

U.S. and Canadian defense officials finalized terms of the MOU during a Dec. 11 signing ceremony at the Pentagon. Representatives from the U.K. and Australian defense ministries followed suit a day later, ratifying the terms of the MOU during separate ceremonies at the Pentagon and the State Department, respectively.

Noting the effort “has proved to us to be an excellent program [and] an excellent example of international cooperation and collaboration,” Canada’s Joint Strike Fighter program manager, Michael Slack, said his nation is pleased with the final version of the agreement.

“At the end of the day, we reached a consensus on what was going to be required by Canada to operate and sustain these airplanes well into the future,” he said during a Dec. 11 interview.

ITAF first reported in July that representatives from each of the participating nations signed a draft version of the MOU. Since that time, defense officials in each country turned their focus toward garnering approval of the pact’s language within their respective governments.

For its part, the United Kingdom viewed the MOU as a “very important and positive” outcome, after months of formal and informal negotiations between the two allies, personal assurances from senior U.S. defense officials and a contentious debate regarding the transfer of sensitive technology information, U.K. procurement czar Lord Drayson said.

“I wasn’t sure that we were going to get there . . . [but] this is an important stepping stone” for the continued participation of the United Kingdom on the F-35 project, Drayson said during a Dec. 12 press conference in Washington, following the signing of the multinational development pact.

International JSF members have argued for increased access to developing technologies related to the F-35, so they can adequately perform mandatory maintenance and sustainment work through the life of the aircraft, defense sources say.

Earlier this year, Drayson told members of the Senate Armed Services Committee that the United Kingdom would pull out of the F-35 coalition due to a perceived unwillingness by the Pentagon to disclose sensitive technological information.

More recently, a Dec. 8 report issued by a key defense committee in the U.K. House of Commons suggested that the Ministry of Defence “switch a majority of its efforts” toward a “Plan B” alternatives to the F-35, should the U.S. continue to deny full disclosure of sensitive technologies.

But after an intense round of last-minute negotiations, coupled with a personal assurance from U.S. acquisition czar Kenneth Krieg that the U.S. would accommodate their demands for “operational sovereignty” on the F-35, the United Kingdom agreed to the terms in the MOU.

To that end, Defense Department officials also inked individual agreements with Canada and Australia regarding technology transfer issues, senior military officials from those countries told ITAF.

With the Netherlands signing the international procurement pact in November, the remaining JSF coalition members who have yet to sign are Italy, Turkey, Denmark and Norway.

Even with technology transfer issues resolved, the United Kingdom still plans to explore alternatives to the F-35 under the “Plan B” strategy, outlined by the Parliamentary defence panel, Drayson said.

Refusing to go into details regarding those Plan B options, the U.K.’s procurement chief said his government has repeatedly emphasized the importance of seeking F-35 alternatives.

The JSF “provides the military capability we need . . . but it is absolutely right for the United Kingdom to have a plan B,” he said during the Dec. 12 briefing.

While echoing the sentiment that preliminary evaluations of the F-35 have shown the aircraft to be the answer to its fighter requirements, Canadian defense officials are also looking at potential alternatives to the fifth-generation aircraft.

“I think that we are going to look at the full spectrum of capabilities to meet future operational requirements,” Slack said in the interview. “If something emerges that turns out to be extremely capable, who knows? I do not have a crystal ball anymore than you do.”

Canadian defense officials are eying the 2012 time frame for a final decision on what platform, or mix of platforms, will replace the F/A -18E/F Super Hornets that make up the majority of Canada’s fighter fleet.

Production aircraft seen as possible alternatives to the JSF include the JAS 39 Gripen and the Eurofighter Typhoon, along with upgraded versions of the Super Hornet, Col. Dave Burt, Canada’s director for air requirements, said in a brief Dec. 11 interview with ITAF.

That eventual fighter force structure is expected to be transitioned into the Canadian air force between 2017 and 2020, he added.

However, the chances of Canada fielding a mixed fighter fleet are slim, Burt said, adding that the operation and sustainment costs to field two fighter platforms would be too expensive.

“We will look at all options, but from an affordability perspective, that would create significant challenges,” Burt said. “Having a mixed fleet, in relatively small numbers, would be extremely expensive.”

The more likely option would be to select a single fighter aircraft to fill the country’s requirements, he added.

Earlier this year, military officials from JSF partner nation Norway began their own “concept solution study,” evaluating military requirements and the capabilities provided by the JSF and other similar aircraft.

The study covers a wide spectrum of options -- from modifying the nation’s current fleet of F-16s with state-of-the-art systems to fielding a new mixed fleet composed of F-35s and a second fighter, Norwegian Defense Attache Maj. Gen Tom Knutsen said during a brief interview at a Sept. 6 international interoperability seminar in Washington.

Noting the examination of F-35 alternatives probably will not result in any one country leaving the program, Burt said the exploratory efforts were simply geared toward learning what exactly the fighter has to offer, outside the issues relating to the MOU.

“Up until this point . . . a very large part of Canada’s program has been about industrial issues and [technology] transfer issues” in the MOU, Burt said. “We have done a relatively modest operational analysis” of this program, he added.