In the ultimate irony of Cold War-era surveillance, one of America’s most effective spy planes — and literally the fastest plane ever built — could never have happened without the help of its intended target, the Soviet Union.
Turns out the Americans bought the metal it needed to help the SR-71 Blackbird withstand the temperatures of supersonic travel from its longtime rival Russia. These are just a few of the fun facts the Smithsonian revealed in a recent video on the plane.
The documentary features a tour of the SR-71 at the Smithsonian National Air and Space Museum. Former Blackbird pilot Buz Carpenter joins the tour, giving the lowdown on what kept the stealthy plane up in the air. Carpenter flew the SR-71 hundreds of times during its time in service, and he even flew the airplane that now resides at the Smithsonian.
The SR-71 had three nose options: A training nose, a radar nose, and a camera nose capable of taking a 72-mile wide photo. The film in that camera was 5 inches wide and 2 miles long. It had to be processed in 500-foot rolls.
The radar nose wasn’t required for navigation. The SR-71 had a pod that read the location of the stars in the sky and, as long as you gave the plane its initial position on the planet, the plane would know where it was anywhere in the world. This was 12 years before the global positioning system was first imagined by the U.S. military.
While the radar nose could assist with avoiding enemy ground fire, the Blackbird’s jamming and missile countermeasures usually meant — not to mention its 2,200 miles-per-hour speed — enemy surface-to-air missiles missed by a mile. Literally.
That top speed meant the average temperature of the plane’s skin was upwards of 600 degrees. At that temperature, it couldn’t be built with aluminum, so it had to be built with 93 percent titanium – and that titanium came from Russia.
The Russians never knew to whom they were selling the titanium, but they sold enough to build 32 SR-71 Blackbirds — planes used primarily to spy on the Soviet Union. The windows were made of quartz and the plane was built with intentional gaps in the wings and fuselage to account for heat expansion during flight. The airplane grows about 2 inches in width and 4 inches in length because of the frictional heat. The hottest part of the plane could get to 1,200 degrees.
The plane’s engines are unique to the Blackbird because no jet engine can absorb supersonic air. So they were specially designed to expand and contract with the airspeed. The extremely high airspeed gave the jet a unique sonic boom as it broke the sound barrier, and the Air Force routinely overflew foreign heads of state to remind them the U.S. could see them.
During the Vietnam War, President Richard Nixon ordered SR-71 pilots to fly over Hanoi and go supersonic to create a sonic boom as a signal to POWs held at the Hanoi Hilton. The booms let the downed pilots in the prison know that if they could escape, Navy SEALs were waiting on the North Vietnamese coast to help them.
Of the 12 Blackbirds rendered unserviceable (none were shot down), four of those came from tire failure. Engineers solved this by cutting the amount of fuel the plane carried during takeoff. A normal mission would see one or two in-flight refuelings. The plane had to refuel every two hours, either in air or on land.