The Air Force has eliminated Hawker Beechcraft’s AT-6 from the bidding process under the Light Air Support (LAS) program, the company said last week, adding that it had formally requested a review of the decision.

“We have been notified by the United States Air Force in a letter that the Beechcraft AT-6 has been excluded from the Light Air Support competition. The letter provides no basis for the exclusion. We are both confounded and troubled by this decision,” the company said in a statement on Friday.

Hawker Beechcraft had teamed with prime contractor Lockheed Martin [LMT] in the competition to supply the Afghan government with about 20 planes. The elimination would leave only one other publicly declared bidder, the Sierra NevadaEmbraer team with Brazil-based Embraer’s Super Tucano.

The Air Force did not immediately respond to a request on the status of the program.

The Air Force is also looking into buying its own aircraft under a separate program known as Light Attack/Armed Reconnaissance (LAAR). The Air Force has identified the need for a small aircraft that could be used for low scale air support missions that do not require the heavy firepower but also higher cost associated with using traditional support aircraft.

“We have followed the Air Force’s guidance closely and, based on what we have seen, we continue to believe that we submitted the most capable, affordable and sustainable light attack aircraft as measured against the Air Force’s request for proposal,” Hawker Beechcraft said. “We have requested a debriefing from the Air Force and will be exploring all potential options in the coming days.”

The Air Force had been expected to announce an award last summer.