Posted on 12/05/2013 5:28:31 AM PST by C19fan
Until Lockheed Martin finally builds the SR-72 Mach-6 spy plane it announced in November, the iconic SR-71 Blackbird, capable of flying three times the speed of sound, remains the fastest warplane ever flown operationally.
So fast that no missiles fired at it had a chance of hitting.
When the U-2 spy plane was built in the 1950s, its designer Clarence “Kelly” Johnson already knew that it would be vulnerable to enemy defenses.
(Excerpt) Read more at medium.com ...
The SR-71 did not use normal Jet Fuel. It took JP-7.
JP-7 is unusual in that it is not a distillate fuel but is created from special blending stocks in order to have very low (<3%) concentration of highly volatile components like benzene or toluene, and almost no sulfur, oxygen, and nitrogen impurities. It has low vapor pressure and high thermal oxidation stability. It must operate across a wide range of temperatures, from near freezing at high altitude, to high temperature of airframe and engine parts being cooled. Its volatility must be low to make it flash-resistant in these high temperatures.
The very low volatility and relative unwillingness of JP-7 to be ignited required triethylborane (TEB) to be injected into the engine in order to initiate combustion and allow afterburner operation in flight. The SR-71 had a limited number of "shots" of TEB (usually 16) and those had to be managed carefully on long-duration flights with multiple stages of relatively low-altitude air refueling and normal high-altitude cruise flight.
This is an excerpt from Sled Driver a booky by Brian Schul. Its out of print and posted all over the web so I hope he doesnt mind that I copied it here. But all attribution goes to him.
Written by Brian Schul – former sled (SR-71 Blackbird) driver:
There were a lot of things we couldn’t do in an SR-71, but we were the fastest guys on the block and loved reminding our fellow aviators of this fact. People often asked us if, because of this fact, it was fun to fly the jet. Fun would not be the first word I would use to describe flying this plane. Intense, maybe. Even cerebral. But there was one day in our Sled experience when we would have to say that it was pure fun to be the fastest guys out there, at least for a moment.
It occurred when Walt and I were flying our final training sortie. We needed 100 hours in the jet to complete our training and attain Mission Ready status. Somewhere over Colorado we had passed the century mark. We had made the turn in Arizona and the jet was performing flawlessly. My gauges were wired in the front seat and we were starting to feel pretty good about ourselves, not only because we would soon be flying real missions but because we had gained a great deal of confidence in the plane in the past ten months. Ripping across the barren deserts 80,000 feet below us, I could already see the coast of California from the Arizona border. I was, finally, after many humbling months of simulators and study, ahead of the jet. I was beginning to feel a bit sorry for Walter in the back seat.
There he was, with no really good view of the incredible sights before us, tasked with monitoring four different radios. This was good practice for him for when we began flying real missions, when a priority transmission from headquarters could be vital. It had been difficult, too, for me to relinquish control of the radios, as during my entire flying career I had controlled my own transmissions. But it was part of the division of duties in this plane and I had adjusted to it. I still insisted on talking on the radio while we were on the ground, however. Walt was so good at many things, but he couldn’t match my expertise at sounding smooth on the radios, a skill that had been honed sharply with years in fighter squadrons where the slightest radio miscue was grounds for beheading. He understood that and allowed me that luxury. Just to get a sense of what Walt had to contend with, I pulled the radio toggle switches and monitored the frequencies along with him.
The predominant radio chatter was from Los Angeles Center, far below us, controlling daily traffic in their sector. While they had us on their scope (albeit briefly), we were in uncontrolled airspace and normally would not talk to them unless we needed to descend into their airspace. We listened as the shaky voice of a lone Cessna pilot asked Center for a readout of his ground speed. Center replied: “November Charlie 175, I’m showing you at ninety knots on the ground.”
Now the thing to understand about Center controllers, was that whether they were talking to a rookie pilot in a Cessna, or to Air Force One, they always spoke in the exact same, calm, deep, professional, tone that made one feel important. I referred to it as the ” Houston Center voice.” I have always felt that after years of seeing documentaries on this country’s space program and listening to the calm and distinct voice of the Houston controllers, that all other controllers since then wanted to sound like that, and that they basically did. And it didn’t matter what sector of the country we would be flying in, it always seemed like the same guy was talking. Over the years that tone of voice had become somewhat of a comforting sound to pilots everywhere. Conversely, over the years, pilots always wanted to ensure that, when transmitting, they sounded like Chuck Yeager, or at least like John Wayne. Better to die than sound bad on the radios. Just moments after the Cessna’s inquiry, a Twin Beech piped up on frequency, in a rather superior tone, asking for his ground speed. “I have you at one hundred and twenty-five knots of ground speed.”
Boy, I thought, the Beechcraft really must think he is dazzling his Cessna brethren. Then, out of the blue, a navy F-18 pilot out of NAS Lemoore came up on frequency. You knew right away it was a Navy jock because he sounded very cool on the radios. “Center, Dusty 52 ground speed check”. Before Center could reply, I’m thinking to myself, hey, Dusty 52 has a ground speed indicator in that million-dollar cockpit, so why is he asking Center for a readout? Then I got it, ol’ Dusty here is making sure that every bug smasher from Mount Whitney to the Mojave knows what true speed is. He’s the fastest dude in the valley today, and he just wants everyone to know how much fun he is having in his new Hornet. And the reply, always with that same, calm, voice, with more distinct alliteration than emotion: “Dusty 52, Center, we have you at 620 on the ground.”
And I thought to myself, is this a ripe situation, or what? As my hand instinctively reached for the mic button, I had to remind myself that Walt was in control of the radios. Still, I thought, it must be done – in mere seconds we’ll be out of the sector and the opportunity will be lost. That Hornet must die, and die now. I thought about all of our Sim training and how important it was that we developed well as a crew and knew that to jump in on the radios now would destroy the integrity of all that we had worked toward becoming. I was torn. Somewhere, 13 miles above Arizona, there was a pilot screaming inside his space helmet. Then, I heard it. The click of the mic button from the back seat. That was the very moment that I knew Walter and I had become a crew. Very professionally, and with no emotion, Walter spoke: “Los Angeles Center, Aspen 20, can you give us a ground speed check?” There was no hesitation, and the replay came as if was an everyday request. “Aspen 20, I show you at one thousand eight hundred and forty-two knots, across the ground.”
I think it was the forty-two knots that I liked the best, so accurate and proud was Center to deliver that information without hesitation, and you just knew he was smiling. But the precise point at which I knew that Walt and I were going to be really good friends for a long time was when he keyed the mic once again to say, in his most fighter-pilot-like voice: “Ah, Center, much thanks, we’re showing closer to nineteen hundred on the money.” For a moment Walter was a god. And we finally heard a little crack in the armor of the Houston Center voice, when L.A.came back with, “Roger that Aspen, Your equipment is probably more accurate than ours. You boys have a good one.”
It all had lasted for just moments, but in that short, memorable sprint across the southwest, the Navy had been flamed, all mortal airplanes on freq were forced to bow before the King of Speed, and more importantly, Walter and I had crossed the threshold of being a crew. A fine day’s work. We never heard another transmission on that frequency all the way to the coast. For just one day, it truly was fun being the fastest guys out there.
I can't imaging the afterburner roar. I saw one as a teenager coming in to land. It was as loud as a B-52. I grew up in the landing path to a SAC base; I know what a B-52 sounds like.
“The very low volatility and relative unwillingness of JP-7 to be ignited required triethylborane (TEB) to be injected into the engine in order to initiate combustion and allow afterburner operation in flight. The SR-71 had a limited number of “shots” of TEB (usually 16) and those had to be managed carefully on long-duration flights with multiple stages of relatively low-altitude air refueling and normal high-altitude cruise flight. “
Yep. The fuel tanks in the SR-71 actually leak while on the ground. Because the titanium skin expands when the SR-71 gets to speed it had to be engineered with gaps interlocking gaps in the skin so that the aircraft wouldn’t buckle when it expanded. On the ground fuel leaks from these joints. You can throw a match directly into it and it won’t light. SR-71s take off with usually around 40% fuel load. The first job into filight is a refuel with a tanker and gassing up. Flying an SR-71 is WORK, but I would have traded anything to get to do it!
Famous ATC exchange with an SR71:
“Permission to cruise at 50,000 ft?”
“Buddy if you can get up there you can have it.”
“Thank you. Descending from 80,000.”
Just imagine if half the funds spent developing stealth was spent refining the design of the SR71 and Ramjet technology.
Better than stealth, the bad guys would see a plane coming at them and could do absolutely nothing about it. Mach 3.5+.
Talk about sending some people to the negotiating table with their tail between their legs.
That was an awesome read! Having been in the military, this really is heartwarming and brings back many similar memories of the vehicle crews with whom I served!
I will have to find that book on the web and give it a thorough look! Thanks for sharing.
B2 - crazy quiet. You almost cant hear it. It is almost like a UFO.
P51 and F4U - Awesome sounding engines
F16 and F15 - Louder still
F4 Phantom - getting pretty loud
SR71 - loud
B52 yep now your loud!
F111 - Ouch
B1-B - HOLY MOTHER what happened to my ears! Feels like a freaking earth quake.
Space Shuttle? Do ya’ll consider them planes? Whatever they were pretty dang awesome to watch and hear launch. I was at the beach at Patrick AFB and saw one. Felt like the earth shaking and sounded like a huge blow torch. From 25 miles away or so!
F-100;
Wham, bam !
is there a hi-res version of this picture?
Purty frickin’ LOUD! Don’t know the decibel count but it was chest pounding good. Nothing like the former space shuttle lifing off and being 3 miles from the pad though. Now that was some real chest pounding good stuff.
LOL! I did get one story from my friend. He told me that he was once assigned to fly over the Pacific and record the External Tank from the Shuttle program’s re-entry but he was pulled off that mission for something else. Of course that “something else” was never revealed.
Nice!!!
“Though I Fly Through the Valley of Death, I Shall Fear No Evil.
For I am at 80,000 Feet and Climbing.” - At the entrance to the
old SR-71 operating base Kadena, Japan
“Nothing like the former space shuttle lifing off and being 3 miles from the pad though. Now that was some real chest pounding good stuff.”
Awesome. I wish I had managed to see a lift off. Looked awesome! I never got there though...
The sounds of freedom!
Sadly it’s something that can’t be described unless you were lucky enough to be there. I was fortunate enough to have collected tax dollars as a paycheck for 36 years working on the STS and got to see most of them. Thanks tax payers. At least with the money the tax payers put out to help pay me, I did some good things with the money. Unlike big gov itself. :>)
I always thought that was the charm of Iowa Class battleships. Sure stealth can be crucial in some circumstances, but sometimes you want the bad guys to see and understand what you are about to do to them.
LOL, that is priceless!
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