The Mighty J58 - The SR-71's Secret Powerhouse

It's been called "black magic": an engine that can push a plane from 0 to Mach 3.2 without breaking a sweat. Here's how it works.

Be sure to SUBSCRIBE to Tech Laboratories for more awesome technology videos!

J58 Airflow Diagrams:

The Blackbird Family:

"The Plane that Dreams are Made Of":

Join me on Social Media for updates and activity

Questions or Comments? Post them below!

And as always, keep thinking!

~Tech

Archive footage courtesy of NASA, the United States Air Force, and Lockheed Martin.

Written, Directed, Filmed, Edited and Animated by Tech Adams.
2014, Tech Adams Laboratories

[nthdegreedesign]

I worked for Pratt and Whitney in the late 1960's in West Palm Beach, on a drafting board with a slide rule! These magnificent engines were on the assembly floor, an unbelievable feat for that time in our aviation history.

[giantnardman]

The men who designed this engine were simply geniuses. Just 20 years after the ME 262 was introduced, the SR 71 was flying.

[kostathomas]

This is hands down one of the most beautiful engines in aviation history. Beautiful not in terms of appearance, but in terms of the complex feats of engineering which were achieved using mainly slide rules. I'm an aerospace engineer but you don't need to be in order to appreciate the genius that went into this plane.

[rexlee]

Much of the math calculation were by slide rule. I spent 11 years on the SR 71 until it’s retirement. The most difficult and maintenance intense aircraft I’ve ever worked on. The fuel, engine oil, hydro fluid was especially designed for it. Your animation is close. You show the cooling air around the engine as being a smooth run. The nacelles have several large structural titanium main frames around the circumference that are hinged at the top and tie together at the bottom for access to the engine. These frames not only help carry the trust load of the engine but also the load from the outer wing. The velocity of that air shouldn’t be very high. I’ve seen other illustrations on how the SR engines work. One that was correct. Assuming that it’s now declassified you can find it on the Internet. The overall thrust that the SR has is not just from the engine and afterburner but also comes from the inlet. At cruise the spike with its shape has high pressure behind it and low pressure near the front. The spike pulls the airplane along. If the correct position for the spike at a certain speed and condition is not maintained, a condition call an inlet unstart will occur. This causes a violent aircraft yaw slamming the Pilot and RSO heads against the canopy. Also causes skid marks.

[lardawg]

One of my friends (Robert G Sowers)was selected from the B-58 program to be the first instructor pilot for the SR-71 . Funny story he told flew the SR-71B model trainers of which there were only 2 made. In 1967 him and his student had to eject because of a double generator failure and engine flameout 7 miles from Beale AFB. Since there were only two B models trainers he "destroyed half of the fleet". When his fellow pilots teased him about crashing and destroying half of the fleet he responded with " I didn't crash it, I wasn't even in it".

[LoneWolf-ypmo]

Proud to say that I worked at Pratt and Whitney for 37 years. I heard so many stories of the people that created such marvels !! I was there to see the last of these magnificent engines being built and had the honor of working on them. . I worked in guarded cages on such incredible engines. The people that created these machines were nothing short of GENEOUS. It was an AWESOME job. I learned fast and ended up with a great career. Also proud to say that Pratt had enough confidence in me to send me all over the world to do maintenance of many aircraft, commercial and military. Sad to say that Pratt is only a shell of it's former glory.

[autarchprinceps]

How is it, that this still seems advanced in 2019?

[joesimon]

oh...yeah...not complicated after all....

[seankirby]

The wing's pointy parts make it go fast and the wings spinny parts make that possible.

[JamaicanMeCrazy]

I think I have enough information now. I'm gong to build one.

[FredPilcher]

What an incredible feat of engineering genius it was, from tip to tail, and all done without computers.

[nawtynick]

One of the best explanations of this engine i've ever seen. Really impressive.

[ericbeltrami]

what an amazing engine, and just to think they designed this 50 some odd years ago, the people that created that engine must have been absolute genius level in engineering. What a machine!

[johnshupek]

From 1964 to 1966 I worked at P&W's FRDC (Florida Research and Development Center). My job was to design the internal cooling for the hi-pressure first stage turbine blades and vanes for the JT11D-20/22 (USAF J-58). Basically my job was to make sure the the turbine blades and vanes didn't burn up and destroy the engine and the aircraft. At that time we were doing major upgrades on the engines to put them in the 34, 000 lbs s.t. range. These were not production line engines, they were all hand-built. As a young Engineer straight out of the "Cookie Jar" (Cal Poly Pomona Aero Engineering) this was a great job! We engine people always looked at the SR-71A "Blackbird" as a couple of J-58s with a bunch of Titanium wrapped around them. I'm sure that Lockheed didn't see it that way! Buy the way, we designed these engines using slide rules. We used an IMB 1620 (16K) card-reader and an IBM 360 (360K) mainframe for our overwhelming computer power! Think of it ... 360K of computing power, who could possibly need anything more powerful that that! The J-58/SR-71A will always have a soft-spot in my heart! Years later I retired from Northrop Grumman as one of their Program Directors on the F/A-18E/F "Super Hornet" program. I currently own and operate the Skytamer Images website at www.skytamer.com.

Concerning the comment about a Mach 3.2 video of the SR-71A. It's tough enough to take a video or even snaps of a Cessna 172 from a Cessna 150. I've done it. Possibly the CIA or the USAF could have asked the Russians if they could borrow a recce MiG-25 Foxbat for an in-flight photo shoot.

[mdlanor]

The people that designed this engine are absolute geniuses. The SR-71 first flew in 1967. Kelly Johnson was an absolute genius. The design of the SR71 was so futuristic and a modern marvel. The fuel tanks leaking while the SR71 was on the ground. Shows just how ingenious the people involved with the SR71 were. The Titanium used for the airframe and skin of the SR71 had to expand. From the friction of the Atmosphere, before the fuel tanks stopped leaking. SIMPLY AMAZING

[Jyoumon]

This is still one of the most amazing freaking aircraft ever built and most ludicrously built engines are a perfect fit for it, This is one of those times where Math, Art, and Science all come together absolutely beautifully.

[williampittmon]

I was serving at Beale afb in 1975. I worked in transportation shuddling flight crews to their planes from main base.Beale was quite a large SAC base and kept about 10 or so b 52's loaded down with bombs at the head of the runway. A friend and I had the privilege of making sure all flight crews vehicles at the alerted pad were in perfect functioning condition in case of an emergency. This was a restricted area and wasn't even visible to the main base. Although it was also the runway for the SR71. Quite a few times we watched as the pilot and navagation officer emerged from the motorhome- looking vehicle that took them up to the store. They appeared to be wearing Gemini type pressured space suits.my friend and I were amazed as the two man crew climbed into the cockpit. At that time cables we're plugged in from the start carts which were almost louder than the jet. (Open header exhaust). The start carts would spin the motors up until they fired.(Awesome spectical). One of the things about the blackbird is that it was built for speed and didn't perform well at low speeds. This is why from the wheels starting to roll to being up and out of sight seemed to take mere seconds. The fact that they would stretch several inches at cruising speed they were very loose and leaky on the ground. The hanger floors were covered in fuel oil and didn't really look safe. The Air Force maintained a small museum that featured the extreme camera equipment showing photos from 80000 ft. The resolution was so good, the pictures could be blown up to clearly read a license plate on a vehicle or the number on the jerseys of school kids playing football. That amazes me to this day. I would not trade those memories for anything. At time they flew practice flights with a T-38 off his wing. Every once in a while you would hear an explosive Sonic boom only to look up and see that the SR had disappeared.im still blown away by the fact they built this awesome machine without the aid of computers or many of the devices we take for granted today and is still the fastest airplane we know about.

[paulbrouyere]

I saw one flying middle of the ‘80’s at an air show in Belgium. I could smell the combustion before I saw the plane. It is truly awesome! Unbelievable Kelly Johnson and his team achieved this wonder of technology in the ‘50’s.

[islamkillsAmericans]

To my eye, there is no man made machine more beautiful and awe inspiring to behold than the "blackbird". The importance of the fact that it flew the highest and the fastest seems to only add icing on the cake. When I first saw one, close up, less than ten feet away, I was struck by it's sight. Without explanation or understanding of it's  stats,   just by witnessing it's size, lines, shape and gargantuan engines,   intuition alone  communicated the greatness of this awesome flying beast. The thing impresses itself not so much as a magnificent artifact from the past but rather one seemingly granted to us from the future. It's seamless matte black titanium skin, known to perspire while in full flight, wore evidence of it's experience in extreme and unreachable environments, The blazing torch it flew against had left it with a multicolored patina on it's glass "wind shield". . To all servicemen and scientist with first hand knowledge of this great machine, please do not divulge technical aspects which the current tyranny we face may use\

[dannz]

I have looked at this aircraft up-close and it is a great design. The genius that went into this design is now nearly sixty years old and still beats anything remotely comparable with what we have today. 
The Blackbirds are an everlasting tribute to the men and women that conceived and built them.  Awesome!