While various projects aimed at creating new airliners capable of exceeding the speed of sound have already been launched, a quick glance in the rear view mirror reminds us how the SR-71 Blackbird remains one of the most efficient aircraft ever designed on Earth.
Of course, it is not an airliner, but a spy plane made for very high altitude flights, observation, and stealth.
Created in 1964 in the context of the Cold War, it remains, 51 years after its manufacture, the fastest aircraft in the world. Capable of exceeding Mach 3 (more than three times the speed of sound in the air), it still holds several records, including that of the highest speed at high altitude: 3529.56 km / h at 25,929 meters.
Its performance was ensured by the creation of a new type of reactor in several stages. Where traditional reactors compress air to bring it into the combustion and post-combustion chamber by adding fuel, the SR71 had several pipes acting as bypass as soon as its speed exceeded Mach 2.2. By adding uncompressed air to the post-combustion chamber, the reactor functioned more like that of a rocket, producing more thrust with less fuel.
If the plane has not been in service for years, since 2013, the USA evokes the design of a possible direct successor to the SR-71, the SR-72 which would again be a supersonic plane produced by Lockheed Martin. This time it would be equipped with hypersonic missiles.