Originally, the designations' suffix letters were not only used to designate different versions of the same basic aircraft type (as in standard USAF designations), but also to distinguish between individual aircraft of the same type (e.g. YF-113A, YF-113C and YF-114C were all MiG-17Fs).

Apr 17, 2000 · The U.S. Air Force's classified YF-113G aircraft was a MiG-23, not an early effort to explore radar-evading technologies, as reported earlier (AW&ST Apr. 10, p. 18). The existence of the...

The MiG-21s and Shenyang F-7Bs were called the "YF-110" (the original designation for the USAF F-4C), while the MiG-23s were called the "YF-113". [2][6] The focus of Air Force Systems Command (AFSC) limited the use of the MiGs as tools with which to understand the performance, capabilities, and qualities of the enemy.

Boeing Bird of Prey at the National Museum of the United States Air Force. YF-118G Bird Of Prey: The ‘Stealth Fighter’ Lost To History Archived 2022-07-05 at the Wayback Machine, 1945.

May 15, 2001 · 'The U.S. Air Force's YF-113G aircraft has been identified as a 1970s stealth testbed and as a MiG-23, but both of these are wrong, according to an observer and some USAF documentation ( AW&ST Apr. 10, 2000, p. 18; Apr. 17, 2000, p. 33).

Oct 16, 2010 · In the early 1990s Dennis F. "Bones" Sager was handpicked to lead a "classified prototype aircraft" called the YF-113G from design to first flight. As a fighter pilot and experimental test pilot, Sager accumulated over 2,900 flight hours in …

Aug 4, 2018 · In the early 1990s, Dennis F. "Bones" Sager was handpicked to command a "Classified Flight Test Squadron" that led a "classified prototype aircraft" called the YF-113G "from design to first flight."

Sep 18, 2006 · The YF-110 designation is believed to have been used by MiG-21s, the YF-112 by the MiG-17, and the YF-113 by the MiG-23, though the YF-113G designation was used by a more highly classified black world programme.

Jul 25, 2011 · Sager accumulated over 2,900 hours of flight time in 54 different aircraft types. He was also hand-picked to be the lead on a classified prototype aircraft known as the “YF-113G” from design to first flight.

Feb 21, 2016 · The aircraft bore US designations prefixed by YF- with numbers ranging from around 110 to 118 with letter suffixes. For example, YF-114C may have been a MiG-17F used in the Have Ferry program.