It is said in The Aerospace Daily & Defense Report that Airbus and Boeing are jointly attempting to unseat Lockheed Martin from South Korea’s KF-X indigenous fighter program, offering stealth know-how from Europe that could not be supplied from U.S. sources.

With Korean Airlines as the local partner, the pair are likely to be proposing the Boeing F/A-18E/F Super Hornet as a base design for the KF-X. The defense ministry’s procurement office, the Defense Acquisition Program Agency (DAPA), issued a request for proposals for KF-X development on December 23, 2014.

The Boeing-Airbus KF-X proposal should be an economical alternative to a fighter design of the defense ministry’s Agency for Defense Development (ADD) that Korea Aerospace Industries has been expected to build with technical assistance from Lockheed Martin.

According to DefenseNews.com, Seoul aims to produce 120 KF-X jets between 2023 and 2030. The state-funded ADD has long studied a twin-engine concept, either of the C103 design that looks somewhat like the F-35 or the C203 design following the European approach and using forward canards in a stealth-shaped airframe. Both of the twin-engine platforms would be powered by two 18,000-pound (80 kN/8,165 kgf) engines, ADD officials said.

Korea Aerospace Industries, on the other hand, prefers a single-engine concept, dubbed C501, which is to be built based on the FA-50, a light attack aircraft version of the T-50 supersonic trainer jet co-produced by Lockheed Martin. The C501 aircraft, powered by a 29,000-pound (129 kN/13,154 kgf) engine, is designed to be fitted with a limited low-observable configuration and advanced avionics.

The U.S. limits the technology that its companies can transfer abroad. Thus, South Korea lacks technology in many fields, such as active, electronically scanning radar. Nevertheless, Airbus, as an airframe company, is probably involved in the Boeing bid as a supplier of stealth know-how that the U.S. company is not authorized to provide.

A budget of 8.6991 trillion won ($7.9171 billion) approved by the finance ministry this month must be intended to pay for development of the ADD KF-X. However, parliament has not yet authorized that spending or the launch of full-scale development, nor can it do so before it votes on the government’s 2016 budget next December.

In the meantime, KAL (Korean Air Lines) looks likely to submit the cheaper alternative, based on the Super Hornet, to DAPA in response to its request for proposals.

Industry officials previously told Aviation Week that Boeing was proposing the Advanced Super Hornet, an update of the F/A-18E/F with a weapons pod and conformal tanks. Other industry officials said Boeing was working with Korean Airlines. Now different officials say that Airbus is also on the team.

This is not the first time that Boeing has offered non-U.S. technology to South Korea. When proposing an advanced F-15 version called the Silent Eagle for the separate F-X Phase 3 fighter program, Boeing suggested technology transfer from Israel Aerospace Industries, an industry official says. Lockheed Martin won F-X Phase 3 with the F-35 and in return is supposed to back KF-X development.