Pilot-physicians were previously assigned only to an operational flying squadron in their respective aircraft, with their main assignment as a pilot, but also with clinical duties seeing patients, usually the aviation medicine clinic, depending on the pilot-physician's medical specialty. On 21 April 2011 the USAF Pilot-Physician Program (PPP) was completely revised to make "... the most of the special resources of Air Force officers who are simultaneously qualified both as pilots and flight surgeons...", with a senior pilot-physician selected by the Air Force Surgeon General to be Program Director, and assignment of designated command, staff, research, training, and education billets as well as duty in operational units. A P48VX Air Force Specialty Code (AFSC) is assigned to those medical officers on aeronautical orders as a pilot-physician and assigned to one of these designated PPP billets. Pilot-Physicians are entitled to conditional flight pay (i.e., Aviation Career Incentive Pay or ACIP), that is, only if assigned to an active flying position and flying a prescribed number of hours monthly.