El Bunto asked:
I wonder if they still do it or has it been subcontracted too?
From globalsecurity.org:
The Combat Flight Inspection (CFIN) aircraft performs in-flight wartime/peacetime/contingency inspections and evaluations of Air Traffic Control systems and procedures (e.g., instrument departures, arrivals, and approaches). The aircraft ensures navigational aids (NAVAIDs) provide safe guidance for instrument flight, especially at night or adverse weather. Since 9/11 over 900 CFIN sorties (4,500 hours) were flown in support of OEF/OIF. The Air Force reservists flew and maintained the C-29A aircraft, a military version of British Aerospace Hawker 125-800 light corporate executive transport. Six were ordered by USAF for the combat flight inspection and navigation mission roles.
By a Memorandum Of Agreement (MOA) between the Air Force and the Federal Aviation Administration (FAA), the FAA accepted responsibility for the flight inspection program from the DOD in March 1991. As a part of this MOA, the Air Force transferred its organic CFIN aircraft to the FAA. The FAA assumed responsibility to operate and maintain the fleet (maintenance and fuel) while the Air Force provides flight crews.
In 1991 the Air Force turned over flight inspection and its C-29s to the FAA and went from 150 people to just 24. Those two dozen pilots, technicians, maintenance and support staff are responsible for a worldwide flight inspection mission. The 1st Aviation Standards Flight was a new mission for the Air Force Reserve and the 507th Air Refueling Wing. As of 01 June 1998, the 1st Aviation Standards Flight with 23 full- and part-time citizen airmen stood up at Will Rogers Airport, Oklahoma City. When fully manned, the flight consisted of 23 people - one officer and three enlisted AGRs (Active Guard Reserve) who are full-time people, and seven officer and 12 enlisted traditional reservists.
The C-29 didn't have the range and capacity to support worldwide deployments, had an operational availability of 80%, and suffered from severe wet wing corrosion problems. These capability gaps and deficiencies limited the Air Force’s ability to provide rapid and flexible support to mission tasking. In response, the Air Force and FAA established a program to replace the C-29 with the Bombardier Challenger 600 (CL-600) series aircraft. Six aircraft were required to support operational war plan tasking. The MOA stipulated the FAA will procure five new aircraft and the Air Force one. The MOA also required the Air Force to fund procurement of any military unique avionics. By 2011 the FAA had already procured four CL-600 series aircraft and phased out three C-29s. Purchase of this aircraft continued the conversion of the CFIN fleet from the C-29s to CL-600 series aircraft and satisfies the Air Force MOA commitment. Now that the Air Force has funded the fifth aircraft, the FAA has also contracted for the sixth and final CFIN aircraft in FY09 and initiated phase out of the last three C-29s.
Since the mission went to the FAA the aircraft were all given N-reggies and a smart blue and white colour scheme.