SR-71 blackbird

yesterday marked 47 years since the sr-71 blackbird set a record on it’s flight from new york to london. the aircraft traveled in a little under 1 hour and 55 minutes. the 1806 mph trip holds the record for the fastest transatlantic flight.

the lockheed sr-71 was developed during the cold war, originally serving as a reconnaissance plane that could avoid being shot down by russian aircraft or their surface-to-air missiles. the blackbird was designed to fly at more than three times the speed of sound— the build team ran into many design challenges to develop such a high speed aircraft. beyond the sleek aerodynamics, the greatest challenge was developing an engine that could fly at the such speeds.

previously developed american rocket-powered aircraft had flown faster than the lockheed, but the rocket engine didn’t need to ingest air mixed with fuel, ignite the mixture, and create thrust. the greatest obstacle the engineers faced was that the air for the jet engine had to be traveling slower than the speed of sound (mach 1) when it entered the engine. some supersonic jets used inlets to the jet engine that slowed down the air— this would reduce the shockwave created by the supersonic air and would avoid stalling the engine. if the engine did stall (known as an unstart) it would need to be restarted mid-flight. i’d say it’s not rocket science but it literally is.

with the high rate of obtainable speed by the sr-71, a more complex inlet was used to control the airflow into the engines. the spike-shaped cone at the front of the inlet could be moved back and forth to control where the shockwave would enter. by monitoring the speed, atmospheric conditions, and engine specs, the pilot could adjust that cone along with a set of doors located on the outer walls of the inlet. with this capability, the shockwave could be positioned in a way that would act as a speed bump of sorts and slow down the incoming air to mach 0.6— this was a more ideal speed for air to enter.

the result of this action was air entering the inlet at roughly 2100 mph. within 20 feet, it slowed down to a speed of 600 mph. this didn’t entirely avoid unstarts but it made them significantly less likely. the end result of this intricate & complex system was the fastest jet aircraft known to man. the official top speed was mach 3.2— but some pilots claimed to have flown around mach 3.5— the average speed flown was around mach 3.0 (2224 mph)

For the New York to London flight, maj. james Sullivan flew the SR-71 blackbird 80,000 feet above New York. as he began his journey over the atlantic, he flew 3,461 miles all the way to London. the trip lasted 1 hour, 54 minutes, 56.4 seconds.

The last flight of the SR-71 took place Oct. 9, 1999.