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U-2 Vs SR-71
At Lockheed’s advanced development group, the legendary Skunk Works in Burbank, work on a revolutionary intelligence aircraft had already begun before the shooting down of Gary Power’s U-2. This innovative aircraft had to fly faster than any aircraft before or since, at greater altitude, and with a minimal radar cross section (RCS).
Developed from the Lockheed A-12 and YF-12A aircraft, the SR-71 (unofficially known as the “Blackbird”) performed its maiden flight on Dec. 22, 1964, and the first SR-71 to enter service was delivered to the 4200th (later 9th) Strategic Reconnaissance Wing at Beale Air Force Base, Calif., in January 1966.
With a top speed of Mach 3+, throughout its nearly 24-year career, the SR-71 remained the world’s fastest and highest-flying operational aircraft. From 80,000 feet, it could survey 100,000 square miles of Earth’s surface per hour.
By contrast the U-2 Dragon Lady has a top speed of 410mph and can fly above 70,000 feet.
Still, the U-2 is still in active service today while the US Air Force (USAF) retired its fleet of SR-71s on Jan. 26, 1990.
Which was easier to track by radar and infrared, the much faster and higher-flying SR-71 with afterburner on or the much slower and high-flying U-2 which has no afterburner and wouldn’t show up as much on infrared?
Both easy to track with radar
Damien Leimbach, former US Air Force (USAF) U-2 Avionics Technician, explains on Quora;
‘Either plane is pretty easy to track with radar.
‘While there were some aspects of the SR-71’s shape that may have made it less observable by Radar than planes of comparable size from that era, it was still clearly visible on Radar. The shape was a function of its purpose, any reduction in RCS was mere serendipity. It was fired on hundreds of times (some estimates as many as 800) over places like Vietnam and Libya. While I can say that it was never shot down, that is also not to say that it was never hit.
‘And you don’t shoot 800 Radar guided missiles at something difficult to see with Radar. We even added a special compound to the JP-7 fuel that was supposed to ionize in the exhaust and scatter Radar waves but that was ended after just a few years. They realized the rest of the plane was still pretty visible so there was no point.
‘The seven U-2’s that were shot down with Radar guided SAM’s expose that particular aircrafts vulnerability to Radar guided missiles all too well.
‘There were attempts to make the U-2 less vulnerable to SAMs of course. Paint with iron balls mixed in, or active jamming signals were all tried but, in those days, they were not very successful. These days we have much more compact and powerful computers so now it is much easier to spoof the missile than it is to try to make the plane invisible to Radar. Our U-2’s still flies over some very nasty spots with very nasty missiles, but none have been shot down since 1969. There is a reason for that.
IRST
‘Infra-red tracking was simply not a thing the way you make it sound.
‘First, there really aren’t any high altitude, Infra-red guided SAMs. They do have some fairly long-range air-to-air missiles that are IR guided, but those only reach their max range when they have the advantage of being launched at Mach 1 and 50,000 feet. Shooting from the ground, fighting thicker air and gravity is going to severely cut their capabilities. And they are all modern designs.
‘The SR-71 was retired in the 90’s, and IRST (Infra-Red Search and Track) was in its infancy. Back then it would have had a max detection range of about ten miles. Since the U-2 and SR-71 fly higher than that, it wouldn’t have been a concern. So afterburner or not, you weren’t going to track either of them on IR in the 90’s or before.
SR-71 easier to spot on IRST than the U-2
‘Today, if the SR-71 was still flying, it would be much easier to spot on IR. Modern IRST missiles have 100NM range, especially with a rear-aspect view. The plane gets unbelievably hot regardless. Temps in the wheel wells exceed 400 degrees F during a high-speed dash, which is why aluminum had to be mixed with the latex in the tires. Otherwise they’d melt.
‘The U-2 is the opposite. It comes down freezing cold.’
Leimbach concludes;
‘If you look at this picture carefully, you can see the outline of the inboard and outboard fuel tanks traced in frost. The fuel in the wings gets colder than 32 F, and when the plane dips down into warm moist air water will condense on the wings and freeze.
‘That one is going to be much harder to see on IRST, but not impossible.’
Be sure to check out Linda Sheffield Miller (Col Richard (Butch) Sheffield’s daughter, Col. Sheffield was an SR-71 Reconnaissance Systems Officer) Twitter Page Habubrats SR-71 and Facebook Page Born into the Wilde Blue Yonder for awesome Blackbird’s photos and stories.
Photo credit: Unknown and Screenshot from YouTube video
