Saint Grendel: The Bastard

The SR-71 Blackbird is nothing short of a legendary aircraft that is even recognizable to those who are not aviation enthusiasts, as it is a record breaker with a very famous pedigree and service history (some of which is still highly classified). Many pilots gave them the nickname “Habu”, after a venomous pit viper indigenous to the island of Okinawa in Japan where many of them were based during and after the Vietnam War.

What some may not know, is that there are a number of different variants of the aircraft out there that are not well known, in particular the one we have on display at Hill AFB museum.

The CIA's A-12 Oxcart came first in the family tree.

In reality, the first variant of the Blackbird was the A-12, also known as the Oxcart, which was the even faster, but slightly smaller, shorter ranged version for the CIA that predated the SR-71 that was based in the famous Groom Lake (Area 51). Then there is the SR-71A, which was of course the main production variant for the USAF. The SR-71B is a rare, stepped cockpit, two seat trainer variant, of which only two were built. Then there was the YF-12, another rare version that was meant to be an interceptor armed with an early variant of what would later evolve to become the AWG-9 radar and AIM-54 Phoenix missile system used by the F-14 Tomcat.

YF-12, the A-12's pissed off younger brother with a really long range punch.

However, even among all these variants, there is only one that bears the designation of SR-71C, and only one was ever built. It's story technically starts with the catastrophic crash of one of the two SR-71B trainers, and the Air Force desperately needed a replacement. With the limited production of aircraft already over, and there being no backup aircraft built, the Lockheed Skunk works had to think outside the box, which is something they excelled at.

What they came up with was some pretty novel engineering. The company had built a forward fuselage to an SR-71B that was meant strictly for ground testing, but was technically flight worthy. Then, they still had an intact rear section to the YF-12 fighter prototype that had suffered a landing accident earlier. So, the engineers said, "okay let's just Frankenstein this thing and mate the two sections together and see if it works!" so they did.

YF-12 on the left, SR-71 on the right, note the differences.

Not being a production aircraft, it got it's unique SR-71C designation for the one-off build, and it quickly took to the skies. Because of the somewhat slapdash nature of the plane's engineering and construction, pilots immediately reported it was more difficult to fly than any other SR-71, with it suffering from very abnormal trim and control issues, and even had different internal fuel tanks, which resulted in different refueling procedures for pilots.

Because of these difficulties, before it could be accepted by the USAF, there was a sixteen flight test program at Edwards AFB to figure out the issues. The engineers and pilots found that the variable inlet cones and ducts for the engines were not properly in sync, as well as the rudders were not correctly configured, which caused the poor handling characteristics, as well as an incorrectly configured pitot tube. So, measures were taken to provide workarounds for the pilots, as well as mechanical fixes so her flight characteristics would match the other SR-71B exactly. Despite this, it was still given it's unofficial name by the pilots during the tests as, "the bastard" for it's unique difficulties in getting her to fly correctly.

Note the stepped dual cockpit setup on the plane and engine display in the foreground.

With the issues fixed, she went to Beale AFB in California for operational use in 1970. The life of the SR-71C was extremely short with it only achieving 737.3 flight hours, with over 180 of those having been done when it was a YF-12, and it was quickly retired from flight status in 1976, but was still kept as a reserve backup for the sole remaining SR-71B for several years.

Thankfully, Hill AFB museum was granted custody of her in 1990, and she was transported in pieces to Hill in a C-5 Galaxy to be restored later. After two months of work she was restored and was able to be displayed in the museum in 1991 where she remains as one of the most popular displays in Hill AFB museum today, as she is one of a kind.