Claims by Hawker Beechcraft that the U.S. Air Force’s choice of Embraer’s AT-29 Super Tucano over its AT-6 to equip the Afghan air force is “fundamentally flawed” and will cost U.S. jobs are being dismissed as misinformation by winning bidder Sierra Nevada Corp. (SNC).

The normally closed-mouthed SNC has issued a public rebuttal of the claims as Hawker Beechcraft’s (HBC) lawsuit challenging the Air Force’s decision works its way through federal court, accusing its rival of using delaying tactics.

“Urgent requests for the A-29 from Afghanistan continue to languish because Hawker cannot provide an acceptable capability, but will not let anyone else provide it either,” says Taco Gilbert, vice president of ISR business development, in an SNC statement.

The point-by-point rebuttal is SNC’s response by a campaign by HBC and Americans for Job Security, a conservative-leaning “pro-business” group that has launched a website and letter-writing drive to pressure Congress to oppose the deal.

The AT-6 was eliminated from the LAS competition as “technically unacceptable” on Nov. 1 last year. Hawker Beechcraft Defense protested its exclusion, but the Government Accountability Office rejected the protest as untimely. This cleared the way for the award of a $355 million contract for 20 aircraft to SNC, the only other bidder, on Dec. 22.

On Dec. 27, HBC filed suit against the Air Force, seeking a legal review of the decision. In response, the Air Force issued a stop-work order on Jan. 4. Motions must be filed with the court by March 6.

Deliveries to the Afghan air force are scheduled to begin in April 2013, but are likely to be delayed by the litigation, the Air Force says.

Alexandria, Va.-based Americans for Job Security says it “is outraged by the Obama administration’s recent decision to turn its back on the proven American aerospace manufacturing community.”

SNC challenges the claim that the loss of the LAS contract will cost 1,400 U.S. jobs. “Only two prototype AT-6 aircraft are in existence. The AT-6 is not currently in production and does not support any U.S. manufacturing jobs,” the company says.

SNC estimates the LAS contract will support more than 1,200 U.S. jobs, with another 50-plus jobs to be created in Jacksonville, Fla., where final assembly will be performed.

“Over 88% of the dollar value of the A-29 Super Tucano comes from components supplied by U.S. companies or countries that qualify under the Buy America Act. No new jobs are being created in Brazil as a result of this contract,” SNC says.

The rising rhetoric comes as HBC chairman Bill Boisture takes over as acting president of Hawker Beechcraft Defense. Jim Maslowski retired from the post effective Jan. 31