One of the original participants in the Air Force’s 2017 light attack experiment has filed a second protest with the Government Accountability Office (GAO), criticizing the service’s decision to procure a small number of two separate off-the-shelf aircraft by the end of the year.

Air Force Materiel Command Gen. Arnold Bunch confirmed Nov. 21 that Air Tractor Inc. had filed a new protest in a Defense Writer’s Group event in Washington, D.C. Per the GAO website, the protest was filed Nov. 1.

Air Tractor had originally partnered with L3 Technologies – which in June merged with Harris to become L3Harris Technologies [LHX] – to provide its AT-802L Longsword turboprop aircraft in the Air Force’s effort to demonstrate the capabilities of an off-the-shelf aircraft to perform light attack and close-air support missions in 2017 at Holloman Air Force Base, N.M.

Since then, the Air Force has chosen to move ahead to procure two to three aircraft each of the Sierra Nevada Corp./Embraer A-29 Super Tucano and Textron Defense [TXT] AT-6 Wolverine aircraft that also participated in the 2017 experiment. The service expressed its intent to procure two to three A-29s for use by Air Force Special Operations Command (AFSOC) at Hurlbert Field, Fla., while a similar number of AT-6 aircraft would be used at Nellis AFB, Nev.

Air Tractor filed an initial protest with the GAO in June following reports the Air Force intended to move ahead with the A-29 and AT-6, but then rescinded it less than two months later. That protest related to the sole-source contracting approach for the A-29 contract, said an industry source close to the situation. The SNC/Embraer Super Tucano had been selected for its potential to help AFSOC with counter-violent extremism operations and interoperability with allied and coalition partners. A-29s are currently flown by multiple partner nations and AFSOC pilots, but so are AT-802 aircraft.

The company said in a statement last Friday that its November protest was related to the proposed sole-source award of the AT-6, for which the Air Force opted for a different contracting approach than the A-29 contract and used an Other Transaction Authority for procurement for experimental purposes.

“Publicly available information shows the AT-6 sole source award is intended for testing and development of AEROnet – a low-cost, exportable datalink architecture, which could be exported to allied air forces,” the company said. “While the development of an exportable datalink architecture like AEROnet is certain to enhance the combat capability of our allied nations, Air Tractor submits that other aircraft warrant consideration for this project vice a sole source award.”

“Air Tractor, Inc. remains committed to supporting the USAF and our allied partner nations. We view ourselves as a reliable industry partner and intend to continue fostering that relationship,” the company added.