The YF-113G was flown at least as early as 1993 and was still flying in 1995 (The Bird of Prey did not fly until September 1996). The description in Sager's bio said he commanded the squadron that "took the YF-113G from design to first flight," which strongly suggested that the airplane was a new design rather than acquired foreign hardware. That said, it should be noted that Sager had been one of the Red Hats pilots that tested various foreign fighter planes. The only other pilot so far confirmed to have flown the YF-113G was also a Red Hat so it's possible that it was, in fact a foreign aircraft and that the words "from design" were in error.

Other Red Hats aircraft flown from 1987 to 1995 include theYF-110E, YF-110L, YF-110M, YF-113C (not to be confused with the Cambodian MiG-17 flown in 1970 as the YF-113C), YF-113E (MiG-23MS), YF-113H, and YF-116A.

If it's still classified, he won't be talking about it. That's the way it works.

Sadly, the greatest need for "blackworld" test pilots these days seems to be with the Red Hats. It's a top priority program. Also, use of unmanned vehicles has been expanding in recent years. There are still some classified aircraft yet to be revealed to the public, though fewer than I had once hoped.

I would very much like to see the "classified advanced technology demonstration prototype" that was flown by Maj. Frank Birk in August 1983. He made the first flight, as well as two additional flights for envelope clearance, stability and control, and initial systems evaluation. The words "advanced technology demonstration" suggest an entirely new aircraft as opposed to a foreign type, and Birk was never a Red Hat.

Doug Benjamin flew four classified aircraft during his Air Force career. So far only one, the Bird of Prey, has been declassified. Were the others Red Hats types or something new? We can only guess at this point.

Between 1992 and 1997, Joe Lanni flew hundreds of sorties in 10 different classified aircraft to evaluate performance, flying qualities, avionics, and military utility. Most of these were definitely Red Hats aircraft. He flew first flights in two "classified prototypes" during this time. One of them was designated YF-24, a departure from the use of three-digit identifiers for classified aircraft (such as the YF-113G and YF-117A). Because of the YF designations and the experimental and developmental nature of the tests, Red Hat pilots refer to their airplanes as "classified prototypes" or "specially modified test aircraft." According to some sources, the YF-24 was first flown in the spring of 1997. One source described it as a "technology demonstrator" and said that there was a "follow-on program." That brings to mind the way that Lockheed's HAVE BLUE was a technology demonstrator with SENIOR TREND (the YF-117A) as a follow-on development of an operational aircraft.

Daniel R. Vanderhorst, a test pilot who had flown Northrop’s TACIT BLUE (reportedly designated YF-117D) was honored in October 2004 at the Gathering of Eagles banquet, a fundraiser for the Air Force Flight Test Center Museum. Unfortunately, he was unable to attend but there was some excitement when his biography was read at the event because it claimed that he had “flown seven classified aircraft to date,” and that many of his flights were in one-of-a-kind technology demonstrators. The Master of Ceremonies said that Vanderhorst had “made his career in so many classified aircraft, there is not much we can say about him on record.” This description proved to be misleading, however. In putting together a short biography for the event, someone unfamiliar with the details of Vanderhorst’s career inadvertently garbled several pieces of information. A list of seven consecutive months of flying sorties in TACIT BLUE (the aircraft type was listed simply as “Classified”) was misconstrued as a list of seven different aircraft. Vanderhorst never saw the text before it was published and so was unable to make corrections. The resulting discussions on ATS ate up a great deal of bandwidth and I am sorry to say that I was I was responsible for much of it.

Since 1983, there have been more than a dozen classified manned aircraft flown at Groom Lake (Area 51). Most of then were foreign types used by the Red Hats but there were at least a few revolutionary new aircraft.

There have also been a great many unmanned craft flown at Area 51, as well as Tonopah Test Range (Area 52) and Yucca Lake (Area 6). Many of them come from the Lockheed Martin Skunk Works. For example, we have seen photos of the P-175 Polecat and the P-170/RQ-170 Sentinel but we have yet to see any pictures of the Desert Prowler.