Friday, January 30, 2009

Video Del Fuego, Part XVII

Back in the late 1950s, the Eisenhower Administration had a problem. The United States had an adversarial relationship with a foreign power that, geographically, we knew almost nothing about. To the Soviet Union, accurate maps were state secrets. They were simply unavailable. So, if we were to have accurate information about where their new missile programs were located, we'd simply have to make our own maps. Not to put too fine a point on it, we'd have to fly overhead and take pictures.

The first aircraft the CIA built to accomplish this mission was the Lockheed U-2. As mentioned before, its basic design was an F-104 fuselage with a gigantic glider wing. It could fly higher than any other aircraft then in existence, and it was thought that this would give the U-2 a measure of protection from surface-to-air missiles. And it did, for a while. Between 1956 and 1960, the U-2 made a number of overflight missions of Soviet airspace, mapping sensitive missile sites. But with each year, Soviet defenses got progressively better. In May 1960, a U-2 flown by Gary Powers was brought down inside Soviet airspace, and the cover was blown.

But a replacement aircraft was already on the drawing board. In 1959, the CIA selected another Lockheed aircraft, the A-12 OXCART, as the replacement for the U-2. It was intended to fly higher and up to four times faster than the U-2: what it couldn't outclimb, it could outrun. The A-12 first flew in 1962, and was flown by the CIA between May 1967 and May 1968.

The interesting thing here is that Johnson introduced this aircraft as an interceptor, not as a spy plane. A natural enough bit of confusion, since there was an interceptor version in the works, the YF-12A Blackbird.

The major differences between the YF-12A and the A-12 are the addition of a second crewman to man the radar and missile systems. The recon equipment was replaced by a powerful AN/ASG-18 fire control radar, paired with the AIM-47 Falcon missiles originally developed for the XF-108 Rapier. There are a few other differences as well, easily visible from the front and side.

But the YF-12A was never authorized for full production. The Soviet bomber threat it was built to counter never really materialized. Instead, when manned recon was transferred from the CIA to the USAF, the USAF wanted a new aircraft developed from both the A-12 and YF-12A. The new aircraft would retain the second crewman, and would also add side-looking radar to the list of capabilities. This new aircraft would become the undisputed King of Speed: the SR-71 Blackbird.

Everything about this airplane is extreme. No manned air-breathing vehicle has ever flown faster or higher. The crews must wear full pressure suits. On the ground, the airplanes fuel tanks seep fuel from numerous seams, to give room for thermal expansion at speed and altitude. The engine lubricant is solid at room temperature, and must be preheated prior to engine start. The Blackbird's structure almost never experiences metal fatigue, since the heating it receives with each mission re-tempers the metal each and every time it hits Mach 3. And it demands the utmost attention from its pilots. At two thousand miles per hour, a pilot's attention cannot wander. A course error of one degree means half a mile per minute lateral deviation. The extreme operational conditions impose a hazard on the crew. Of 32 SR-71s built, 12 were lost to accidents.

But despite numerous missions over North Vietnam and other denied airspaces, no Blackbird was ever lost to enemy action. This isn't to say that it hadn't been tried. SR-71 crews had a fool-proof anti-missile system. Whenever they heard a launch warning, they simply advanced their throttle. Those few missiles that could reach their operational altitude of 85,000 feet poked through the empty air below and behind their intended target.

In the end, the march of technology brought the Blackbird's end. Not in the form of better defenses, no one ever did manage to build the system that could bring her down. But in the form of ever-improving satellite photography. The Eisenhower Administration was also pursuing a third recon option in the form of the Corona program. The technology was a long time in gaining maturity. But the latest generation, capable of beaming their pictures in real time back to headquarters, finally bring a capability to the table that the SR-71 can't match. Finally, in 1999, the Blackbird made its last flight, leaving several records that will probably stay untouched for decades to come.

But there's a postscript to the Blackbird story. Remember the YF-12A? Even though it never saw full production, its fire-control radar and missiles were such a useful combination that a slightly more advanced variant ended up finding life in the proposed F-111B air-to-air version of that aircraft. Well, the Navy decided that the F-111B was a stinkburger, but kept the AWG-9 radar and AIM-54 missiles for their new fleet-defense interceptor: the F-14 Tomcat. The combo of the AWG-9 and Phoenix could simultaneously track and engage six targets at once, at ranges of up to 100 miles away. Not that this has ever been proven in action. The U.S. Navy only fired two AIM-54s in anger, in 1999 against Iraqi MiG-25s southeast of Baghdad. Both missed.

It's really weird how things work out sometimes.

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