Aviation technology advanced quickly during the 20th century, and alongside the evolution of aircraft, the systems created to detect aircraft also improved. In the early 1960s, Lockheed started designing a streamlined, high-speed reconnaissance aircraft, using the best materials on the market: titanium. The difficulty, however, was that most of the global supply of titanium was sourced from the Soviet Union.
A special aircraft requires special materials
The SR-71 Blackbird project was managed by Lockheed’s Skunk Works. This aircraft was designed to be a modernized version of the A-12, the company’s earlier reconnaissance aircraft. Clarence “Kelly” Johnson served as the chief engineer for both projects.
The developers involved in the project faced heavy pressure and strict deadlines imposed by the US government. During his 1964 presidential campaign, Republican candidate Barry Goldwater criticized President Lyndon B. Johnson for permitting the United States to lag behind the USSR in military technology.
The SR-71 was designed to be larger than the A-12 to accommodate additional fuel and enable the installation of a dual cockpit. At the same time, the new aircraft had to exceed its predecessor in speed. The project presented considerable challenges for the engineers at Lockheed, with Johnson recalling years later, “Everything had to be invented. Everything.”
Lockheed engineers came up with a solution
The SR-71 Blackbird was designed for speed, reaching up to 2,000 MPH and maintaining this velocity for extended periods. However, this generated atmospheric friction, causing the airframe’s edges to heat beyond 1,000 degrees Fahrenheit, risking structural damage.
The only viable solution was to cover the aircraft in titanium. As Lockheed explains, “Titanium alloy was the only option for the airframe – providing the strength of stainless steel, a relatively light weight and durability at the excessive temperatures.”
The material proved challenging to work with, due to its sensitivity and brittleness. Engineers at Skunk Works often broke the titanium alloy while using cadmium-plated steel tools, leading to the need for new tools made entirely from titanium. As well, machinists on the production line had to undergo specialized training to learn how to handle the material effectively.
Titanium wasn’t readily obtainable
Along with the material being difficult to work with, titanium was also hard to find. The US didn’t have the ore necessary to produce it. The biggest producer of the material was the Soviet Union. At the time, both countries were in the midst of the Cold War, and the US government didn’t want to give the Soviets any hints as to what they were up to.
Col. Rich Graham, an SR-71 pilot and former wing commander, explained to the BBC:
“The airplane is [92 percent] titanium inside and out. Back when they were building the airplane the United States didn’t have the ore supplies – an ore called rutile ore. It’s a very sandy soil and it’s only found in very few parts of the world. The major supplier of the ore was the USSR. Working through Third World countries and bogus operations, they were able to get the rutile ore shipped to the United States to build the SR-71.”
The SR-71 Blackbird proved itself during the Yom Kippur War
The US was very interested in the Yom Kippur War, a conflict between Israel and a coalition of Arab states – and the SR-71 Blackbird was the perfect reconnaissance tool to see what was happening. Pilots were deployed on missions ranging from between three and four hours, with some taking as long as 11 hours to complete, and they were tasked with gaining information about the positions of both sides.
Col. Rich Graham told the BBC:
“The President wanted to find out whether the Arabs and the Israelis had really moved back from the front line like they said they did. We went over there, took the imagery, came back and showed photographic proof they were both lying about where their forces were. He called both countries and said, ‘Get them back, I’ve got proof you’re not where you’re supposed to be.’ That’s what ended the Yom Kippur War.”
The legacy of the SR-71 Blackbird
The SR-71 Blackbird was operational from 1966 through to 1998, although NASA continued to use the aircraft for an additional year. During its service, it was continuously the fastest aircraft of its time. In addition to the Yom Kippur War, the SR-71 was also utilized during the Israeli invasion of Lebanon, the 1986 US raid on Libya and helped reveal Iranian Silkworm missile batteries.
More from us: Lockheed AC-130: The Gunship That Provided Much Needed Support in Vietnam
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Not everyone was happy when the decision was made to retire the aircraft. Former astronaut and Senator John Glenn wound up writing to President George H.W. Bush:
“Mr. President, the termination of the SR-71 was a grave mistake and could place our nation at a serious disadvantage in the event of a future crisis. Yesterday’s historic transcontinental flight was a sad memorial to our short-sighted policy in strategic aerial reconnaissance.”