Over a U.S. Air Force base in the southern New Mexico desert, pilots are testing some off-the-shelf options as the military looks for its next light-attack aircraft, a plane that could partly replace the A-10. Test flights for the light-attack experiment known as the OA-X initiative were being conducted Wednesday at Holloman Air Force Base in southern New Mexico. Air Force Secretary and former New Mexico congresswoman Heather Wilson was on hand along with other top officials. Pilots are putting commercially available planes through various scenarios that would emulate combat missions and other tasks such as search and rescue and reconnaissance. The testing includes the A-29 Super Tucano made by Sierra Nevada Corp. and Textron Aviation's Scorpion jet plane and its AT-6 Wolverine turboprop.