The U.S. Air Force has issued a stop-work order to Sierra Nevada and partner Embraer on their recently awarded $355 million Light Air Support (LAS) contract as the team’s onetime competitor, Hawker Beechcraft, claims unfair contracting practices in federal court.

But the Air Force is sticking by its controversial award and the stop-work could just be a precautionary move. A temporary restraining order was likely to come that would have prevented work, and the Air Force issued its stop-work order Jan. 4 in an effort to expedite the process of sorting out the claims made by Hawker.

“The competition and source-selection evaluation were fair, open and transparent,” according to an Air Force spokesman, Lt. Col. Jack Miller. “The Air Force is confident in the merits of its contract award decision and anticipates that the litigation will be quickly resolved.”

An Air Force official says that the service’s paramount concern is fielding the first LAS aircraft next year, with the last of 20 to be delivered in 2014.

Hawker was dropped from the competition in November, apparently, although information dribbled out publicly and mostly from Hawker over the last month.

Just before New Year’s Eve the Pentagon publicly announced that Sierra and Embraer had won the $355 million deal (Aerospace DAILY, Jan. 4). The Hawker AT-6 and Embraer Super Tucano were evaluated by the Air Force in a flyoff conducted in January 2011. Sierra is the A-29 Super Tucano’s U.S. lead in the LAS competition, and final preparation of the aircraft will occur in Jacksonville, Fla.

Hawker filed suit against the Air Force on Dec. 27 in the Washington-based U.S. Court of Federal Claims, seeking to negate the November decision to exclude the AT-6 from the competition (Aerospace DAILY, Nov. 23, Dec. 26).

The court filing came after a Government Accountability Office (GAO) decision, dated Dec. 22 and released Dec. 23, in which congressional bid referees dismissed a bid protest by Hawker. According to GAO paperwork, Hawker’s protest was based on procedural issues regarding the timeliness of notifications. But the GAO ruling also provides insight into the Air Force’s decision-making — namely, that the service found the company’s AT-6 proposal insufficient.