Presolicitation notice from the Department of Defense, specifically the Department of the Air Force, is seeking engineering services for the maintenance, testing, research, and design of medium caliber aircraft guns. The focus is on the 20mm M61A1/A2 used on various aircraft models and the 30mm GAU-8 used on the A-10 aircraft. These guns are fixed mounted on the aircraft and are used to suppress or incapacitate aerial or ground targets. The purpose of this task is to improve the reliability, maintainability, and supportability of the weapon systems. The contract is sole source to General Dynamics-OTS, Inc. located in Williston, Vermont.