History

“… The cadets now had 107 feet of fire-breathing titanium in their faces as the SR-71 leveled and accelerated, in full burner, on the tower side of the infield, closer than expected, maintaining what could only be described as some sort of ultimate knife-edge pass…”

The stunning cover photo of this article shows the well-known image of an SR-71 Blackbird making a very low flyover. Brian Shul explains the intriguing backstory behind this incident in his book Sled Driver.

“I was flying the SR-71 out of RAF Mildenhall, England, with my back-seater, Walt Watson; we were returning from a mission over Europe and the Iron Curtain when we received a radio transmission from home base. As we scooted across Denmark in three minutes, we learned that a small RAF base in the English countryside had requested an SR-71 fly-past. The air cadet commander there was a former Blackbird pilot and thought it would be a motivating moment for the young lads to see the mighty SR-71 perform a low approach. No problem, we were happy to do it. After a quick aerial refueling over the North Sea, we proceeded to find the small airfield.”

“Walter had a myriad of sophisticated navigation equipment in the back seat and began to vector me toward the field. Descending to subsonic speeds, we found ourselves over a densely wooded area in a slight haze. Like most former WWII British airfields, the one we were looking for had a small tower and little surrounding infrastructure. Walter told me we were close and that I should be able to see the field, but I saw nothing. Nothing but trees as far as I could see in the haze. We got a little lower, and I pulled the throttles back from the 325 knots we were at. With the gear up, anything under 275 was just uncomfortable. Walt said we were practically over the field yet; there was nothing in my windscreen. I banked the jet and started a gentle circling maneuver in hopes of picking up anything that looked like a field.”

“Meanwhile, below, the cadet commander had taken the cadets up on the catwalk of the tower in order to get a prime view of the fly-past. It was a quiet, still day with no wind and partial gray overcast. Walter continued to give me indications that the field should be below us but in the overcast and haze, I couldn’t see it. The longer we continued to peer out the window and circle, the slower we got. With our power back, the awaiting cadets heard nothing. I must have had good instructors in my flying career, as something told me I better cross-check the gauges. As I noticed the airspeed indicator slide below 160 knots, my heart stopped and my adrenalin-filled left hand pushed two throttles full forward. At this point, we weren’t really flying but were falling into a slight bank. Just at the moment that both afterburners were lit with a thunderous roar of flame (and what a joyous feeling that was), the aircraft fell into full view of the shocked observers on the tower. Shattering the still quiet of that morning, they now had 107 feet of fire-breathing titanium in their face as the plane leveled and accelerated, in full burner, on the tower side of the infield, closer than expected, maintaining what could only be described as some sort of ultimate knife-edge pass.”

“Quickly reaching the field boundary, we proceeded back to Mildenhall without incident. We didn’t say a word for those next 14 minutes. After landing, our commander greeted us, and we were both certain he was reaching for our wings. Instead, he heartily shook our hands and said the commander had told him it was the greatest SR-71 fly-past he had ever seen, especially how we had surprised them with such a precise maneuver that could only be described as breathtaking. He said that some of the cadet hats were blown off and the sight of the plan form of the plane in full afterburner dropping right in front of them was unbelievable. Walt and I both understood the concept of “breathtaking” very well that morning and sheepishly replied that they were just excited to see our low approach.
As we retired to the equipment room to change from space suits to flight suits, we just sat there-we hadn’t spoken a word since “the pass.” Finally, Walter looked at me and said, “One hundred fifty-six knots. What did you see?” Trying to find my voice, I stammered, “One hundred fifty-two.” We sat in silence for a moment. Then Walt said, “Don’t ever do that to me again!” And I never did.”

“A year later, Walter and I were having lunch in the Mildenhall Officer’s club and overheard an officer talking to some cadets about an SR-71 fly-past that he had seen one day. Of course, by now the story included kids falling off the tower and screaming as the heat of the jet singed their eyebrows. Noticing our HABU patches, as we stood there with lunch trays in our hands, he asked us to verify to the cadets that such a thing had occurred. Walt just shook his head and said, ‘It was probably just a routine low approach; they’re pretty impressive in that plane.'”

Top image: courtesy of Robin Harbour

Photo by U.S. Air Force

The plane was given the nickname “Blackbird” after being painted all black.

Before Gary Powers’ U-2 was shot down, work on a ground-breaking espionage plane had already started at Lockheed’s advanced development unit in Burbank by the storied Skunk Works. This ground-breaking aircraft had to fly farther and faster than any other aircraft before or since, while also having a smaller radar cross-section (RCS).

The strategic advantages of the U-2’s aerial reconnaissance during these stressful Cold War times were highly prized by President Eisenhower. Then Lockheed’s customer in Washington asked them to construct an airplane that cannot be shot down and to do it quickly.

According to the explanation provided in the article Creating The Blackbird which was published on the Lockheed Martin website, Kelly Johnson, one of the greatest aircraft designers of the 20th century, and his Skunk Works team had a history of producing “impossible” technologies on incredibly short, strategically crucial deadlines.

Johnson, though, insisted that this new aircraft belonged in a different class than anything that had come before. “Everything had to be invented. Everything,” he said. He vowed that Skunk Works would complete its most difficult task to date—getting the cutting-edge, difficult, boundary-pushing aircraft into flight in under twenty months.

The new aircraft was designed to fly at more than 2,000 mph and was required to maintain a record-breaking speed for hours at a time, even though other aircraft of the time could do something similar but only in brief bursts powered by afterburners. Friction with the atmosphere at such a speed produces temperatures that would melt a traditional airframe.

Dealing with the heat posed a number of problems that seemed intractable in terms of material selection and design, with expected temperatures on the aircraft’s leading edges surpassing 1,000 degrees Fahrenheit. Using titanium alloy, which offered the strength of stainless steel, a relatively low weight, and resistance to extreme temperatures, was the only way to solve these issues.

However, it turned out that titanium was a very delicate material from which to construct an airplane. A lot of anger on the Skunk Works assembly line and new training sessions for Lockheed’s machinists resulted from the brittle alloy’s tendency to shatter when mishandled.

Furthermore, the temperature outside the cockpit window would be -60 degrees Fahrenheit, despite the fact that friction would cause great heat to be produced at the aircraft’s leading edges. Ben Rich of Skunk Works spent countless hours trying to figure out how heat could be dispersed across the entire aircraft. Then he remembered a straightforward lesson from one of his college courses: Heat is produced and absorbed by black paint. The plane was given the nickname “Blackbird” after being painted all black.

The first flight of the original Blackbird, known as the A-12, occurred on April 30, 1962. The SR-71, which had more fuel capacity than the A-12 and a second seat for a reconnaissance systems officer, quickly replaced the smaller, single-seat A-12. The SR-71 made its debut on December 22, 1964.

The possibility that the Blackbird would be detected and shot down decreased even further as the size of the radar image was shrunk. Despite the positive initial test results, the U.S. government requested an even lower radar profile because of concerns about Soviet radar advancements.

In order to prevent radar signals from bouncing off surfaces, the engines had to be shifted to a more covert mid-wing location, and a radar-absorbing component had to be incorporated into the paint. The Blackbird’s full-scale replica was then raised on a pylon for radar testing at a hidden Skunk Works facility in the Nevada desert. The tests were carefully timed to avoid being observed by Soviet satellites, and the outcomes were impressive: On Soviet radar, the more than 100-foot-long Blackbird model would be seen as larger than a bird but smaller than a person. The team had achieved a 90% reduction in radar cross-section.

When Air Force Major Rudolph Anderson was killed while flying a U-2 reconnaissance mission over Cuba on October 27, 1962, during the height of the Cuban Missile Crisis, there was increased pressure to put the Blackbird into service.

In response, Skunk Works persevered through the numerous issues that sprang up as flight testing pushed the envelope. They did so carefully and creatively. The Blackbird broke records almost every time it flew and on July 20, 1963, at an incredible height of 78,000 feet, it sustained a speed exceeding Mach 3. The difficulties persisted: in order to navigate while zipping through the air at 3,000 feet per second, the rules of navigation had to be revised. Highways, rivers, and urban areas as visual references for traditional flying were replaced with mountain ranges, coasts, and vast bodies of water.

The Blackbird’s piloting was a punishing job that required complete focus. “At 85,000 feet and Mach 3, it was almost a religious experience,” said Air Force Colonel Jim Wadkins. “Nothing had prepared me to fly that fast… My God, even now, I get goosebumps remembering. ”

Even the finest air defense systems were hopeless against the Blackbird at that speed and altitude. The control panel’s warning light turned red when anti-aircraft weapons were fired. But because surface-to-air missiles frequently miss wildly and explode miles away from their intended target, that would typically be the last the pilot would see of the attempted strike.

Photo by Jim Ross / NASA, U.S. Air Force, Lockheed Martin