Why would the blackbird fly so high? I looked it up and it says they can fly up to 90,000ft.
In: Other
Well it’s a plane that should make photos from high above enemy territory.
The higher you are the less likely it is someone stops you.
The project was stopped once satellites could do the same job from even higher above.
It flew so high not only to save fuel, but so it didn’t get blown out of the sky by enemy missiles or planes. Weaponry (and usually radar) of the time wasn’t good enough to fight or track at that altitude. Even if they somehow detected the plane being there, the enemy didn’t have a weapon or plane they could use to shoot it down.
It was a spy plane used for very, very, *very* sensitive operations and the government could not afford to lose them by being shot down or intercepted. So they were designed to fly really fast and really high to help keep them safe.
[removed]
As I remember in the late 1950’s an U-2 spy plane had been shot down over the Soviet Union. Causing a big international incident, so the SR71 was created to fly higher and faster than the Soviet missiles.
ELI5 – the air up there is less dense, it’s easier to fly faster at 70,80 or 90K feet above the ground. [Flying high and fast put it out of the reach of Soviet Surface to Air Missiles (SAMs) for decades.](https://theaviationgeekclub.com/even-if-it-was-faster-than-the-blackbird-the-sa-2-sam-was-never-able-to-hit-the-sr-71-heres-why/) If when they could climb that high, systems weren’t that accurate or the missiles were never fast enough to catch the SR-71.
When missiles were introduced that could pose a threat ([starting with the SA-5](https://en.wikipedia.org/wiki/S-200_(missile))) the Blackbird wasn’t allowed to fly over the USSR and some of it’s client states that got those missiles.
There are two main reasons.
Firstly, the altitude made it difficult for foreign nations being spied on to counter the SR-71. No fighter/interceptor could fly high and fast enough, and no missile could climb fast enough and track well enough to hit it.
Secondly, the air up there is thinner allowing the plane to fly with less friction. Even so, due to its immense speed, the Habu heated up so much in flight that almost the entire plane had to be made of titanium, which at the time (late 50s) was a very exotic material.
The Blackbird and the U-2 that came before it were spy planes that flew over the Soviet Union and warzones where the enemy would would try to shoot them down.
The Soviet Union managed to shoot down a U-2 that could fly at 70,000ft.
The Blackbird solved this problem by flying higher and faster making it more difficult for it to be shot down.
Because these planes were photographing Soviet airfields, factory’s, nuclear facilities, test site, aerial defences and everything in-between the Soviets really wanted to stop them.
Flying at mach 3 at 90,000ft was the best way to keep them safe. The enemy air defence did not have enough time or energy to detect the plane then get a missile that high and fast to shoot it down.
I was just at the Airforce museum this weekend and they had one there. It is a really cool looking plane.
Antiaircraft and air defense missiles that they had to worry about were mostly on the ground having been warned that it is coming. The aircraft could fly far above and far away from these while doing it’s mission of taking pictures. If they detected incoming missiles they had time to hit the gas and outrun them once their automated warning system alerted them even if they were flying a bit slower from turning.
The SR-71’s cruising speed was just above mach 3 so was going faster than 2,223 mph normally when going mostly straight and even faster if a missile is inbound. While the exact top speed it flew hasn’t been released it is speculated to be about mach 3.5-4 with the fuel they used as the plane had been theoretically designed to go mach 6 on paper. Another reason you want to fly far above the ground when flying at such insane speeds so you don’t get distracted and crash into the ground.
85,000 ft is 16 miles above the planet’s surface. If the pilot looks down at his dashboard for just 5 seconds at mach 3 you have traveled 3 miles! That means if they were to all of sudden to pitch straight down it would only take roughly 30 seconds to crash into the Earth at it’s cruising altitude.
200 aircraft tried to intercept it and 4,000 missiles were fired at the SR-71 and none of them ever hit them, not a single SR-71 was taken out by enemy forces. During the SR-71’s lifetime we developed a missile that could go mach 5 ourselves that might have been in the bay of a few experimental SR-71 variants but when outrunning enemy missiles it didn’t have to go faster than their top speed even just stay ahead long enough for them to run out of fuel. I know it outran Soviet SA-2s SAM missiles fired by North Korea which could go mach 3.5 but maybe even some that were faster and this is great reason to stay far away from the ground.
Latest Answers