Alenia North America and General Dynamics are teaming up to vie for a U.S. Air Force contract to build 350 T-38 fast jet trainer replacements.

The teaming agreement, announced today, is likely to round out the field of would-be competitors for the so-called T-X competition.

The competition is not likely to start until 2014 at the earliest, but the announcement comes as the Air Force plans to conduct a T-X industry day later in the month.

Alenia North America will provide the Alenia Aermacchi M346 — dubbed the T-100 for the U.S. sales campaign — while General Dynamics C4 Systems will handle prime contractor responsibilities, including subcontractor management and systems integration work, based on a letter of intent jointly signed by both companies.

The team vows to build the aircraft in the U.S.; they are currently built in Venegono, Italy. Executives have not said, however, if all of the aircraft for the U.S. would roll off of a stateside final assembly line or merely some portion of the buy if the team wins the competition.

Current M346 customers include Italy, Israel and Singapore.

The GD/Alenia team joins a familiar field. BAE will compete with the Hawk trainer and Northrop Grumman as its U.S. manufacturing lead. Lockheed Martin and Korea Aerospace Industries will propose the T-50. One exception in this arena, which has competed for other work abroad, is the arrival of Boeing in the competition.

The company plans to propose a clean-sheet design based on the forthcoming U.S. Air Force request for proposals. This is seen by some as a risky proposal because the Air Force has said it prefers to buy a trainer with as little development cost as possible. Boeing will either have to underwrite some of the development cost — as it has done with the KC-46A tanker program — or risk competing with off-the-shelf designs that may need less costly modifications.

In replacing the aging and maintenance-needy T-38 fleet, the Air Force plans to buy not only a fleet of aircraft, but an end-to-end training system, including sophisticated ground-based training aids.

Past performance evaluations could be a challenge for Alenia. Last month, the Air Force decided not to renew a contract with the company to train the burgeoning Afghan Air Force to operate its refurbished G222 tactical airlifters, which were purchased by the U.S. This was Alenia’s first prime contract with the Air Force, and the decision came within a year of the service’s decision to terminate purchases of the C-27J, a more modern tactical airlifter, and ground all those that have been delivered.

However, it is unclear whether the service will consider the G222 contract suitable for inclusion in the team’s past performance criteria. More likely, it will assess its performance on the earlier contract with Alenia to convert the old G222s into usable aircraft for the Afghan Air Force. Though they were all delivered, there were times when the company had to pay for excess labor hours because it underestimated the challenge of refurbishing the aircraft.

Ultimately, though, the Air Force is likely to emphasize the cost of developing, procuring and operating the aircraft in its eventual T-X decision.