Close Air Support (CAS) depends on close cooperation between ground and air units, predicated on mutual understanding and close proximity. CAS also depends on aviator training and aircraft characteristics. Despite predictions of air power's dominance, air-ground teams are the most effective employment of military power. This thesis demonstrates that the modern Army Combat Aviation Brigade mimics the WWII Tactical Air Command's effective, close working relationship between air and ground units. However, Army Aviation lacks fixed-wing attack aircraft, forcing the Army to rely on the Air Force for fixed-wing CAS. Utilizing non-organic means for critical functions violates unity of command and results in CAS performed by aircraft primarily designed for other missions. This situation is likely to worsen in the coming years. This thesis summarizes Army-Air Force CAS issues since WWII and argues that the Army requires an organic fixed wing attack aircraft to bridge the capability gap between its helicopters and USAF platforms at the tactical level. Fielding such aircraft would free the Air Force to focus on its broader missions while enhancing the capabilities of Army Aviation.On June 9 2014, a United States Air Force (USAF) B-1B bomber dropped two 500lb GPS-guided bombs on a team of Army Special Forces and Afghan security forces, killing five. Numerous errors on by the aircrew and ground element contributed to deaths on the ground, all of which are historically endemic to Close Air Support (CAS). The terminal controller was unfamiliar with the operating environment and the aircrew could not visually acquire either the friendly or the enemy positions from 12,000 feet above ground level. Because they believed the aircraft's targeting pod could identify friendly strobe lights, the air-ground team "collectively failed to effectively execute the fundamentals, which resulted in poor situation awareness and improper target identification." Sadly, when it comes to CAS, this type of tragic incident is too common.No military cooperation issue creates more acrimony than CAS. CAS has been contentious since the first aircraft teamed with ground forces and remains so today. These friction points are relative priority of CAS and Interdiction; operational control of CAS aircraft and; aircraft characteristics. The history of Army-Air Force CAS largely consists of poor initial efforts followed by the development of workable systems success as effective air-ground teams and aircraft developed on the battlefield. No organizational processes or technology has been able to bridge the Army-Air Force CAS divide. This thesis examines that divide, proposing an Army Fixed-Wing (FW) aircraft as a solution.