The Lockheed SR-71 “Blackbird” is a long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft developed and manufactured by Lockheed Martin’s Skunk Works, which has a hard-earned reputation for making the impossible happen.

The SR-71 operates at extremely high speeds of about Mach 3.2 and altitudes of up to 85,000 ft (25,900 m) to allow it to outrace threats. The SR-71 has such sheer speed that if a surface-to-air missile launch was detected, the bird would simply outfly the missile. The Blackbird evaded all 4,000 missiles fired at it and, to this day, remains the only Air Force aircraft to never lose a crewmember associated with it; whether in the air or on the ground. While flying above 80,000 feet. Six different cameras or sensors on the Blackbird were able to photograph over 100,000 square miles in an hour. Let’s take a look into what made the SR-71 blackbird unparalleled.

“Because of the way the fuselage bends and the wing curves and twists, it looks more organic than mechanical. Most conventional airplanes look like someone built them – this one almost looks like it was grown.”

Peter Merlin

The Design

The SR-71 is still considered the coolest-looking jet ever created. With a long nose and huge after-burners, the jet still looks modern and simply out of a James Bond movie. The Blackbird was designed to operate at extreme velocities, altitudes, and temperatures. The black paint job, designed to increase the emission of internal heat and to act as camouflage against the night sky, earned it the nickname ‘Blackbird’. Titanium was used for the first time in an aircraft and occupies 85% of the structure. Titanium was mainly preferred as the only valid option since the friction caused by air molecules passing over its surface at Mach 2.6 would melt a conventional aluminum frame. The engineering process was so cutting edge that even the tools to build the SR-71 needed to be designed from scratch.

The biggest enemy of the SR-71 was not its rivals, but heat. The jet when at Mach speeds, would heat up so much that it would cause a smooth skin to split or curl, whereas the corrugated skin would expand vertically and horizontally and increase longitudinal strength. Fuselage panels were manufactured to fit only loosely with the aircraft on the ground. Proper alignment was achieved as the airframe heated up and expanded several inches. The outer windscreen of the cockpit was made of quartz and was fused ultrasonically to the titanium frame to increase strength and durability. The temperature of the exterior of the windscreen reached about 600 °F or 316 °C during a mission.

The Shape

The SR-71 was designed with two things in mind, speed and stealth. These two were the basics for the engineers to work on and design the jet. To become nearly undetectable, the engineers gave the jet a very unique and distinctive shape. The wings were blended into the body and the long blade-like surfaces along the forward fuselage, known as chines, aided in deflecting incoming radar waves. The inward-angled twin fins over the engines and the pointed engine cones also decreased the Black Bird’s radar cross-section. The lower fuselage was nearly flat giving the 107-foot SR-71 its sleek and futuristic spear look.

The Speed

The SR-71 was powered by two Pratt & Whitney J58 axial-flow turbojet engines, each providing 32,500 pounds of thrust – enough to power an ocean liner. These engines allowed the SR-71 to cruise at altitudes above 85,000 feet and at speeds up to Mach 3.3, which is about three times the speed of sound! The SR-71 became the highest flying and fastest jet in the world. It could fly from New York to London in under two hours while an ordinary plane would take up to eight hours. The SR-71 was so fast that it could evade a missile launched at it. Flying at a higher altitude than anti-aircraft fire could reach, faster than a missile, and barely visible to radar, the Blackbird could enter hostile airspace practically undisturbed. As a result, no Blackbird was ever shot down by enemy fire.

Pilots or Astronauts?

The people flying the SR-71 were not some ordinary pilots with the usual training. To be selected to fly the SR-71, pilots had to be considered among the Air Force’s best and due to the altitudes, they had to undergo the same rigorous physical training and examinations as NASA’s astronaut did. The pilots also needed special protection to fly the aircraft and were outfitted with pressure suits and helmets that provided pure oxygen. Regarding their uniforms, they simply could not wear their traditional black suits because they were flying at the edge of space. Instead, they wore special pressurized suits and helmets similar to astronaut gear. Hoses at the back of the helmet connected to a supply of 100 percent oxygen. Pure oxygen protected pilots suffering decompression sickness at high altitudes.

Did you know?

1. The camera on the SR-71 could accurately capture the license plate of a car from 80,000 ft.
2. From the cockpit at the pilot can see the curvature of the Earth and stars during daylight while flying in the top 1% of the atmosphere.
3. Due to this critical fuel loss, the airplane had to be refueled immediately after takeoff, before it could continue with its mission.
4. The SR-71’s cockpit was all-analog.
5. A 747 rotates at about 155 knots during takeoff. The SR-71 rotates at a very fast 210 knots.
6. The aircraft used parachutes in combination with wheel brakes to slow itself down.
7. At top speed, the SR-71 would pass the bullet fired out of an M1 Garand Rifle by over 400 feet per second.
8. During it’s 1990 retirement flight, it flew from Los Angeles to Washington D.C. in 67 minutes; a record for the fastest cross-country flight from coast to coast.

The Legend

There might be newer and more advanced jets being manufactured, but no jet will ever hold the rawness and toughness of the SR-71. Arguably the most complicated jet ever built and is rightfully considered as one of the greatest feats of engineering ever. As of 2020, the SR-71 continues to hold the world record it set in 1976 for the fastest air-breathing manned aircraft. Its successor, the SR-72 is being manufactured with the first flight of the demonstrator expected in 2023, while the full-scale aircraft is expected to enter into service by 2030.

Sources

• https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird
• https://airman.dodlive.mil/2017/07/10/airframe-the-sr-71-blackbird/
• https://www.boldmethod.com/blog/lists/2015/03/14-SR71-Blackbird-facts/
• https://edition.cnn.com/style/article/sr-71-blackbird-spy-plane-design/index.html
• Popular Mechanics (Cover Photo)