Airplanes are the fastest means of transport today, and they have advanced technologically since the Wright brothers’ maiden flight. Modern commercial airplanes move at incredible speeds, transporting people and cargo across states, countries, and continents. No matter your destination, you are sure to get there in minutes or hours on an aircraft depending on the distance.
As such, it is unfathomable that a faster aircraft than the ones traversing different airspaces today existed some decades ago. Unless you heard of or experienced the Supersonic Concorde, banned at the start of the millennia. If so, you have yet to hear of the SR-71 Blackbird, the fastest plane ever designed and flown in human history. Designed and built in the late 1950s, the aircraft had a breathtaking body with incredible features contributing to its supersonic speed. The plane broke the sound barrier by miles, moving from New York to London in under two hours. Keep reading to learn more about this remarkable aircraft.
6 Facts About The SR-71 Blackbird
- SR-71 Blackbird was faster than a rifle bullet and could outspeed a missile.
- The plane had a top speed of 2,200 mph (3,450 kph), three times the speed of sound, making it the fastest aircraft of its time.
- The plane holds the record for the highest altitude horizontal flight as it could fly near the edge of space at 85,069 feet.
- Pilots needed to wear uniquely designed high-altitude pressure suits when flying the plane to provide them with oxygen during the flight.
- The SR-71 had two tandem cockpits: one for the primary pilot and another for operating the surveillance systems and equipment.
- The plane could fly completely undetected with special technology that deflected any radar signatures.
The SR-71 Blackbird History
The SR-71’s history dates back to the 1950s when it was launched as a black project, free from the public eye, and a continuation of the Lockheed A-12 project. At the close of 1957, the Central Intelligence Agency contacted the assigned government defense contractor, Lockheed Corporation, asking them to design an undetectable plane. The aircraft was purposed for the intelligence agency’s spy operations. Thus, the project Archangel to build the SR-71 Blackbird project was born.
Works on the project commenced in 1958, with Clarence Leonard “Kelly” Johnson as its head and aircraft designer. Kelly, a prominent airplane designer with his Skunk Works team, had a track record of delivering futuristic technology in an impossible timeline; they were perfect for the job.
In just ten months, the team had come up with ten designs, with the A-10 being the most preferred. However, the plane design was vulnerable to radar detection. However, with additional funding, Kelly and his team set out to fix the issue. In early 1960, the team came up with a good design, the A-12, whose production commenced immediately. A dozen aircraft were built, and on 25th April, the first models took off at Groom Lake.
The SR-71 Blackbird was a derivative of the A-12 aircraft, with several improvements to increase its flight efficiency and support intelligence collection missions. It was designed as a larger aircraft with two cockpits to accommodate the main pilot and a second one for a reconnaissance officer who operated other systems. After perfecting the design, the first SR-71 Blackbird was built; it made its first flight on December 22, 1964.
SR-71 Blackbird had advanced surveillance and radar-deflecting features and the CIA did use it to gather global intelligence at the height of the Cold War.
The SR-71 Blackbird: How It Worked
This supersonic airplane had incredible features that contributed to its seamless operations. Considering it was built in the 1960s when airplane technology was not as advanced as today, you may wonder how the designers created an aircraft with incredible speed and stealth. From the aircraft’s overall design to the engines, all the components were perfectly designed to meet its specific objectives. Since the technology used on the plane was nonexistent then, designers had to innovate from scratch, making it one of the most expensive supersonic planes ever made.
The idea behind the SR-71 was to create a spy in the sky that could fly high and fast yet remain invisible to radar to allow service members to conduct reconnaissance missions. Here is how different features of the Blackbird worked to achieve this.
SR-71 Blackbird’s design had a tremendous impact on the airplane’s operations. Without the proper shape, the airplane could not move as it did, and worse yet, it could not go undetected when infiltrating enemy lines.
Designed for stealth, the plane’s body had various features to eliminate as much radar signature as possible so it could fly undetected. The aircraft had a flat shape with thin tapering sides to deflect radar beams. The design also incorporated chines that extended vertically along the airplane’s body, and special material to absorb radiation.
The unique design features and cesium additives in the airplane fuel worked together to considerably reduce the SR-71 Blackbird’s radar signature, making it almost undetectable. While the shape and incorporated design features made the aircraft’s body untraceable as it flew across the restricted territory, the fuel additives reduced the exhaust fumes’ radar visibility.
The SR-71’s shape and design did allow for better stealth. Some components contribute to the aircraft’s stability and aerodynamics as it traverses and breaks the sound barrier. The chines act as leading-edge extensions that improve airflow when flying, increasing the plane’s agility and handling at high speeds. The components also create powerful vortices that increase the airplane’s power, maximizing its speed and stability. The performance is augmented by the aircraft’s delta wings, which give the supersonic airplane a triangular shape for aesthetics and reduce the drag effect.
The SR-71 Blackbird’s shape and design features also accommodated its speed and ensured it flew undetected.
Engines are the heart of any aircraft. They produce an enormous thrust that propels the plane forward with great force, contributing to the vessels’ speeds. In an ordinary plane, the blades on the plane’s wings suck in air into a compressor, which raises the air pressure as the blades move faster to compress the air. The inducted air is then sprayed with fuel, ignited in the combustion chamber, and pushed to the back of the engine, producing energy to thrust the aircraft forward. All airplanes work on this principle. However, to break the sound barrier, The SR-71 Blackbird designers had to make some twitches.
Foremost, The SR-71 Blackbird didn’t run on an ordinary jet engine. It flew on two Pratt & Whitney J58 turbojet engines. These are unique American jet engines with axial-flow compressors that give the airplane increased thrust, culminating in high speeds. The engine produced a thrust of 32,500 IBF and was especially effective when the SR-71 Hit Mach 3.2 and during takeoff as the plane moved through the runway.
Like standard planes, SR-71s sucked air into the compressor and sprayed it with fuel before igniting. However, compression in the plane’s J58 turbo engine happened in nine stages, supported by air inlets that increased its thrust at different stages. This allowed the engine to work as a standard jet engine at subsonic (below 250mph) and transonic (more than 250mph but less than 760mph), then rapidly switch to a ramjet engine once it breaks the sound barrier. At that point, the engine gave the airplane more than 32,000 pounds of thrust, propelling it to its full speed.
To cater to the increase in temperature on account of friction from the plane’s supersonic speed and high combustion, the engine designers extensively used high-temperature nickel superalloys. These metals could withstand high temperatures of about 800°F to 3200°F in the inlet and afterburner duct, thus preventing engine damage and possible failure. Interestingly, no one has publicly replicated the SR-71 Blackbird engine’s efficiency.
Airframe and Landing Gear
The composition of an airplane’s body is essential to its operations. Consequently, the vessels’ airframes are not just coined from any material. It has to be lightweight and resistant to corrosion to accommodate the aircraft’s high-speed movement. This especially applies to The SR-71 Blackbird, the fastest plane ever built. Its body had to accommodate the high temperatures generated as it flew at thrice the speed of sound.
Titanium was the perfect material to accommodate the SR-71’s speed, preventing damage in its supersonic flight. The material has an excellent weight-to-strength ratio, reducing the aircraft’s weight without compromising its structural integrity. Although a viable option for the SR-71, finances were limited. Lockheed used titanium on 85% of the airframe to control costs and polymer material on the rest.
Notably, the SR-71 Blackbird’s body was not pure titanium but an alloy that softened at lower temperatures. Therefore, the fuselage panels fit loosely, allowing them to attain proper alignment once the aircraft heated up in the air and expanded. This meant that the SR-71 leaked fuel on the runway before taking off. Though this may sound wasteful, it was necessary.
Kelly and his team also had to take the aircraft’s landing into account due to its speed. It needed to have more than just regular landing gear. The SR-71 Blackbird had B.F Goodrich manufactured tires made of aluminum and filled with nitrogen. These components allowed for a softer landing as the aircraft landed at over 300mph. Similarly, the plane deployed a parachute when landing to facilitate stopping and reduce stress on the tires.
The SR-71 Blackbird: Historical Significance
In 1957, the Central Intelligence Agency approached Lockheed, the government defense contractor, to build an undetectable aircraft for surveillance purposes. Thus, the journey to SR-71 Blackbird’s development began.
The need for an undetectable aircraft was especially urgent after the 1960 U2 incident, where a missile shot down a spy plane in Soviet airspace, and the pilot, Francis Gary Powers, was detained by the Soviet authorities. The once top-secret spy plane was shot down by a radar-guided surface-to-air missile developed by the Soviets, proving the need for a stealthier model aircraft for secret reconnaissance missions.
Lockheed eventually achieved the needed stealth and technology when it designed and produced the first SR-71 Blackbird. It took its first flight on December 22, 1964, with the test conducted by pilot Bob Gillard. He broke the sound barrier at 990mph and flew at an altitude of 4900 feet. Since then, the Blackbird recorded over 2,500 hours of flight until its retirement.
The Blackbird was an essential piece of aviation technology during the height of the cold war, as the US government used it to collect intelligence on the Soviets and its communist allies. The aircraft mainly operated in the Kadena Air Base, a strategic operating location in Okinawa, Japan, and primarily flew over Eastern and Central Europe.
Throughout its operations, the SR-71 Blackbird flew 3,551 mission sorties, most successful as the airplane went undetected. However, that was not always the case. The Swedish Air Force sighted the plane numerous times and even had it within shooting range on the plane’s return flights.
One of the notable detections of the SR-71 was on June 1987 when the aircraft was deployed on a spy mission on Soviet postings around the Baltic Sea. The plane lost altitude at 65,000 feet and turned in search of the Swedish coast. Sweden reacted by sending two armed Saab JA Viggens to assess the situation, after which they reported a distressed aircraft but did not resort to any combative response. Nonetheless, the National Security Agency recently revealed that on multiple occasions, the Soviets had given orders to shoot down the plane.
Despite these setbacks, the SR-71’s significance in collecting vital intel during the cold war cannot be downplayed. After serving their purpose, the airplanes became too expensive to maintain due to military budget cuts. Consequently, the US Air Force retired them in 1989, and the last SR-71 operated by NASA for research purposes was retired on 9th October 1999. The aircraft is currently on display at the National Air and Space Museum.
The image featured at the top of this post is ©USAF / Judson Brohmer - Armstrong Photo Gallery.