Embraer has submitted to the Brazilian air force a list of recommendations for suppliers of the engines, avionics, structural components and other systems for the KC-390 tanker/transport.
As the launch customer and owner of the KC-390, the service will make the final decisions soon on the partners who will comprise the supply chain for the jet-powered aircraft that is aimed at replacing the venerable Lockheed Martin C-130.
The Brazilian airframer says the air force's decisions could be made in either late February or during March. Finalising the KC-390's key suppliers is necessary before the company launches the joint development phase that will freeze the aircraft's design.
Recommendations on suppliers are based on the company's internal evaluation, says Fernando Ikedo, Embraer's director of defence market intelligence.
The Brazilian air force is also conducting its own evaluation, and could make supply chain decisions independently of Embraer's recommendations.
"This is the way we've worked for more than 40 years with our Brazilian air force," says Ikedo, noting successful examples of previous programmes including the A-29 Super Tucano and three military versions of the EMB-145 regional jet.
"Everything [with KC-390] is the same way," Ikedo says. "We know each other very, very well."
Key parts of the supply chain, such as the KC-390 engine supplier, remain the programme's biggest unknown only three years before a scheduled first flight in 2014. With a requirement to deliver a 23t payload up to 1,400nm (2,590km), Embraer wants an off-the-shelf engine in the 30,000lb thrust (130kN) category, which includes the CFM International CFM56 and International Aero Engines V2500.
Meanwhile, the air force's Center for Aerospace Technology has begun evaluating a full-scale wooden mock-up of the KC-390 cargo compartment. With a 3.45m (11.6ft)-diameter cross-section, the aircraft is designed to carry up to 80 passengers or up to three high-mobility multipurpose wheeled vehicles.
Embraer also reveals the company is considering the installation of an aerial refuelling boom, although officials have declined to provide details. For the tanker role, the KC-390 has previously been advertised as a hose-and-drogue refueller only.
In the last 10 months, six countries have signed up to eventually order up to 60 KC-390s. That amounts to about half of Embraer's business case to justify launching the aircraft, which was based on orders for 120.