A second industry team has dropped from the competition for the U.S. Air Force’s $16.3 billion T-X advanced pilot training program to supply the service with 350 new jet trainers. Northrop Grumman and its principal partner BAE Systems will not submit a proposal for the requirement, the companies announced on February 1.

The companies “have carefully examined the U.S. Air Force’s T-X trainer requirements and acquisition strategy as stated in the final request for proposals,” the service released on December 30, Northrop Grumman stated on its website. “The companies have decided not to submit a proposal for the T-X trainer program, as it would not be in the best interest of the companies and their shareholders.”

On January 24, the team of Raytheon and Italy’s Leonardo-Finmeccanica group publicly withdrew from the competition. The companies had proposed the T-100 variant of the Alenia Aermacchi M-346 Master for the requirement and selected a location in Meridian, Miss., to assemble the jet. But the partnership dissolved after Leonardo was unable to cut the cost of the jet by nearly a third, Defense News reported, citing unidentified Italian sources.

Northrop Grumman’s withdrawal comes after the company’s Scaled Composites subsidiary in Mojave, Calif., built a new single-engine jet—the Model 400—that was expected to contend for the T-X program. Chairman, CEO and president Wes Bush hinted at the move during Northrop Grumman’s fourth-quarter 2016 conference call on January 26.

“We have not reached a conclusion on that,” Bush said, when asked about T-X. The company has to look at all such opportunities “through the cold, hard winds of what’s the RFP [request for proposals] really tell you and what would the business case look like,” he added. “While it’s interesting that we have made some investments along the lines of supporting this program, we need to be thoughtful as we are on every single one of these RFP activities about what it means going forward. They all have to be good business opportunities for us."

The latest withdrawal leaves two leading teams in the running: Lockheed Martin and Korea Aerospace Industries with the T-50A variant of the single-engine T-50 Golden Eagle; and Boeing and Saab, with a single-engine clean-sheet design. Another partnership of Sierra Nevada Corporation and Turkish Aerospace Industries may also compete, according to published reports. The Air Force has said that it plans to award a contract this year.