GT38
GT Owner
That’s an interesting story with confusing and contradictory information that’s been told over the years. To really understand how this unusual designation evolved, you need to go back to early in the Cold War. Although a lot of information has become muddled because of secrecy, disinformation and the passage of time, this is what I believe is the most plausible explanation.
A lot of people don’t know that the US flew a large number of reconnaissance flights over the Soviet Union in the 50’s, many of them in the Boeing RB-47 (predecessor of the B-52). A lot of RB-47s were being fired on by both SAMS and MiG interceptors, and it was a matter of time before one was lost. There is strong evidence that some were lost, and that the losses were covered up – and are still being covered up to this day.
The military likes code names, and the code name for the RB-47’s replacement was “Angel”. The result of the Angel program was the Lockheed U-2 from Kelly Johnson’s Skunkworks. One version of the origin of the Angel code name was that it described the ultra-high altitude capabilities of the aircraft. The “U” stands for Utility. It was given that designation to divert attention from the aircraft’s true mission, since that designation was used for small non-combat aircraft. (The much-upgraded later version of the U-2 was the TR-2, for Tactical Reconnaissance.)
Even though the U-2 flew at much higher altitudes than the RB-47, eventually the Soviets were able to shoot down Francis Gary Powers’ U-2 in the famous international incident in 1960. By that time, a replacement was in the works for the subsonic U-2. Speed is life in this situation, and so high-speed was a must for the Angel follow-on aircraft - known as Archangel.
The USAF had already begun development of a high-altitude Mach 3 bomber, the North American XB-70. By the time the XB-70s were test flown (only two were built), they were already made obsolete by ICBMs. The Air Force considered a reconnaissance version of the XB-70, designated the RS-70. The RS stood for Reconnaissance Strike, implying a dual-purpose platform. The aircraft was overkill for reconnaissance at 500,000+ gross weights and never got beyond paper studies. Besides, there was already something else waiting in the wings that was purpose-built and even faster.
The Archangel program was also developed by Kelly Johnson. It was a CIA program and the initial aircraft were sometimes referred to as the A-11 or A-12. The A supposedly came from either Archangel or the word “article”, which was sometimes how individual early aircraft were referred to (another bit of deception). Normally, the A designation was used for attack aircraft, which these were clearly not. They weren’t really even military aircraft either, so the whole thing would have been very confusing to anyone who stumbled across these designations. They were also unofficially referred to at the Titanium Goose. Those first aircraft were single-seaters and were slightly smaller and faster than the later two-seaters. That program was also known as Oxcart, which I’m sure someone thought was an appropriate diversionary name for a Mach 3+ aircraft.
There were two versions of the two-seaters; reconnaissance and interceptor. Initially the reconnaissance version was called the RS-71, which was the next number in line after the never-built RS-70 version of the XB-70. The Air Force soon after changed RS to SR, supposedly to designate Strategic Reconnaissance. Thus, the SR-71 name was born. There is a probably apocryphal story that President Johnson flubbed the name when he announced the existence of the aircraft at a press conference in 1964 (for political purposes before the election, of course), transposing the R and S, and that the Air Force changed the designation so as not to have to correct the president. Who knows?
Although I'm convinced that President Johnson's announcement was purely political, one of the reasons given was to mute public concerns of UFO activity. Shortly after that announcement, I happened to talk to an ARTCC (Air Route Traffic Control Center) controller who said they were regularly reporting UFOs to the Air Force - skin paints on radar that were traversing 3-1/2 inches to the sweep on their radar scopes, compared to 3/4 inch per sweep for a Boeing 707 at cruise. He said the Air Force always thanked them politely for the reports, but never seemed concerned or particularly interested, and never called back. As he put it, "That explained everything when Johnson made his announcement!"
The interceptor version was the YF-12A, and had several different physical characteristics from the SR-71, most notably ventral fins under the engines and a shorter nose chine. The Y denotes a pre-production aircraft. The F was for fighter, which all interceptors were designated. No production F-12s were built – just three YF-12s.
Production numbers of the Archangel/Oxcart A-11/A-12s and the SR-71s isn’t clear, but there were probably a dozen or fewer of the single seaters, and thirty-some SRs. Some of the confusion comes from claims that airframes were built and hidden away, which I suppose is possible. A more likely explanation is the fact that they often painted two tail numbers on one aircraft, one on each side, to throw off spies. Sometimes fictitious tail numbers were used too. The public may never know the actual number of airframes that resulted from the Archangel/Oxcart program.
Finally, there was the M-21/D-21 program. The D-21 was a ram-jet powered reconnaissance drone that was carried on the top of the M-21 (a modified YF-12A). The M and D designations were from Mother and Daughter. The D-21 was faster than the YF-12A once launched, and did not risk a crewmember over hostile territory. The program was not successful, and one aircraft and one crewmember were lost in testing. Ultimately the D-21s were carried by B-52s and were accelerated to ram-jet ignition speeds by a booster rocket, but they saw limited use. That program was fairly successfully kept quiet until well into the 1990s, as I recall, when the remaining D-21s turned up at the boneyard at Davis-Monthan AFB in Tucson.
This is all from memory, so please correct me if I’ve got something wrong. Indy GT has got a lot of info from personal experience on the engine side of things.
I've often wondered how "RS-71" would sound to the ear today if we'd become as accustomed to it as we have with "SR-71" - which has become synonymous with speed. Somehow, RS-71 just doesn't sound as good as SR-71!