How Fast is Fast
by Mark Gamas
How fast is the fastest you have ever gone? 80mph? 100mph? If you’ve ever been on an airliner it’s probably more like 450mph. How fast would you like to go? What is the highest speed that you can actually see yourself going? We all know that once you leave the atmosphere, speed is much easier to achieve and maintain so keep your thoughts inside the stratosphere. How about 1,000mph? 2,000mph? What if I told you that we have the technology today to push you to 2,193mph at an elevation of 85,069ft in an air-breathing plane? Would you be interested in a ride? That’s Los Angeles to Washington D.C. in 1 hour and 3 minutes at an altitude 3 times that of Mt. Everest. Superman is no longer the only one faster than a speeding bullet.
This is not some new technology that has recently been developed with the aid of computers. This aircraft was designed and built with a slide rule and has been in flight since it accidentally left the runway during a high speed taxi trial on April 25, 1962. It is the SR-71 (Blackbird) and it has achieved and maintained every performance record for manned, air breathing flight for the last 40 years.
Not a single manned plane to date has been able to match it. Those who have flown this bird belong to a very elite group of speed junkies. The only other people who have ever traveled faster than them are those who have flown on the space shuttle. The drawback of belonging to this club is that the pilots of the Blackbird are subjected to such extremes that they must under go a specific pre-flight regime and wear the same flight suits as their brethren aboard the shuttle.
The first time I laid my eyes upon a picture of this aircraft, I found it sleek looking but aerodynamically awkward. I was unimpressed with what I thought was a mediocre plane and never really gave it a second thought. Those who have seen it in action, however, respect this plane with the reverence I hold for the man who invented indoor plumbing. The local Japanese at one of its overseas bases in Okinawa nicknamed it “Habu” after a black, highly dangerous snake that lived in the area. The name stuck and it is now incorporated into the patch awarded to the elite crews that fly these special planes. The plane has lived up to this namesake and has proven itself to be one very tough bird to tame. Out of the fifty planes that were built in this series, 20 of them have been lost due to accidents and mechanical breakdowns. No plane has ever been lost due to enemy action.
As it was originally designed to do, Habu flew higher and faster than even the missiles that were shot at it. Take this account of Lt Col William Burk Jr. for example:
In the fall of ’82, I flew from Midenhall on a mission over Lebanon
in response to the Marine barracks bombing. President Regan ordered
photo coverage of all the terrorist bases in the region. The French refused
to allow us to overfly, so our mission profile was to refuel off the south
coast of England, a Mach 3 cruise leg down the coast of Portugal and Spain,
left turn through the Straits of Gibraltar, refuel in the western
Mediterranean, pull a supersonic leg along the coast of Greece and Turkey,
right turn into Lebanon and fly right down main street Beirut, exit
along the southern Mediterranean with another refueling over Malta,
supersonic back out the straits, and return to England.
Because Syria had a Soviet SA-5 missile system just west of
Damascus that we would be penetrating (we were unsure of Syria’s
intentions in this conflict), we programmed to fly above eighty
thousand feet and at Mach 3 plus to be on the safe side, knowing
that this advanced missile had the range and speed to nail us.
And as we entered Lebanon’s airspace my Recon Systems Officer
in the rear cockpit informed me that we were being tracked
by that SA-5. About fifteen seconds later we got a warning
of active guidance signals from the SA-5 site. We couldn’t tell whether
there was an actual launch or the missile was still on the rails,
but they were actively tracking us. We didn’t waste
any time wondering, but climbed and pushed that throttle,
and said a couple of “Hail Kellys.”
We completed our pass over Beirut and turned toward Malta,
when I got a warning low-oil-pressure light on my right side engine.
Even though the engine was running fine, I slowed down and
lowered our altitude and made a direct line for England. We decided
to cross France without clearance instead of going the
roundabout way. We made it almost across, when I looked out
the left window and saw a French Mirage III sitting ten feet off
my left wing. He came up on our frequency and asked us
for our Diplomatic Clearance Number. I had no idea what he was
talking about, so I told him to stand by. I asked my backseater,
who said, “Don’t worry about it. I just gave it to him.”
What he had given him was “the bird” with his middle finger.
I lit the afterburners and left that Mirage standing still.
Two minutes later, we were crossing the Channel.
Habu was originally conceived by the genius engineer Clarence “Kelly” Johnson as a protégé to the U-2 even before Gary Powers was shot down over Russia. Kelly knew the weakness of the U-2 because he and his famous “Skunk Works” of Pasadena, California had built it and he was certain that he and his team could build a plane that would be such a leap in technology that it would be safe for several years before the Russians would be able to defend against it. Of course great leaps in technology come with great challenges and this was certainly the case with the Blackbird. Everything for this plane had to be built from scratch. Nothing for this plane was of the shelf. Everything from nuts and bolts to electrical wiring had to be re-engineered to meet the high demands that Habu puts on her many parts each time she takes to the air. The closest to ready technology came in the form of the engines produced by Pratt & Whitney for a Navy plane that was never built. Even these had to be extensively modified to be able to maintain the Mach 3.2 (that’s 3.2 times the speed of sound or 3.2 times approximately 800mph) that is cruising speed for the Blackbird.
Another engineering challenge came in the form of what material to use for the skin of the plane. The usual aluminum would melt away at the 800+ degrees Fahrenheit that would be reached at cruising speed. Kelly came to the rescue with a new material that was being produced by only one company in the U.S. This new material was a titanium alloy that had extreme potential. In working with this new material, new techniques had to be created to make this alloy workable. Fully 1/3 of the pieces molded for the Blackbird were set aside to be tested to make sure they were up to par and able to handle the pressures that was required of them. For each step forward in technological innovation made, a step up and over a new problem also had to be achieved. New welding techniques were needed to hold the new alloy together and the usual cadium coated tools in the mechanics toolboxes had to be replaced once it was found that the cadium was slowly eating away at the titanium. Oddly enough, in order to get enough titanium to produce Habu, the CIA set up dummy corporations and purchased the bulk of this rare material from Russia, the very country that it was being built to spy on.
Probably the greatest design problem was passed off to Ben Rich, the man in charge of the propulsion system. A normal jet engine sucks air in, combines it with fuel, lights it and sends it out the back. The problem Rich was saddled with was how to keep the sonic shockwaves created by the plane out of the engines. If the shockwaves were to enter a standard jet, it would cause there to be a momentary lack of oxygen to burn and put out the fire. With no fire, there is no thrust. Rich eventually came up with the ingenious idea of putting a cone in front of the engine that moved in and out to control the amount or air that the engine picked up. In the end, his movable spike and the exit duct turned out to produce about 83% of the thrust needed to speed the bird along. That’s not to say that the Blackbird’s engines are weak. Each of her two engines individually produces more power than the Queen Mary’s four huge turbines together at 160,000 shaft horsepower. That’s over 8,000 times the power of my not so little 240hp truck in each of Habu’s engines.
The problems faced by the Blackbird weren’t left behind once she left the construction hangar. Even with the sophisticated movable spike in place controlling the airflow into the engine, sometimes the airflow would be disrupted and an “unstart” would happen. These where very serious as the engine went from producing 16,000 – 20,000 lbs of thrust to becoming 16,000 lbs of drag in a fraction of a second and would shake, rattle and roll the plane so much that pits would be tossed about like rag dolls. On one such occasion over West Virginia, the pilot accidentally tried to restart the wrong engine and fell for approximately 50,000 ft before he was able to relight them. When he did, the sonic boom from only 30,000ft broke windows for miles around and even toppled a factory’s tall chimney crushing two workers to death. A computer was eventually installed so that when an unstart would occur, rudder would be applied and the engine would be restarted before the pilot even knew that he had lost an engine.
And mechanical problems weren’t the end of Habu’s troubles. Politicians, as usual, had their two cents to put in about the project. Once several of the planes were built, then Secretary of Defense Robert McNamara decided that there really wasn’t a need for such a high performance machine. He argued that since the Blackbird was so far ahead in technology of any potential enemy, why did we need it? Satellites were becoming more popular and didn’t need all the maintenance and upkeep that a fleet of specialty planes would need; although satellites were locked into an orbit and if you wanted pictures of a certain spot, you would have to wait until the satellite made it there. Others had suggested using the Blackbird as a high-speed interceptor to shoot down enemy planes even before they made it to our border. McNamara rallied behind the idea that it wouldn’t be able to hit anything, let alone fire a missile, when it was traveling three times the speed of sound completely ignoring the fact that Kelly had already achieved a better than 90 percent hit rate from a Blackbird that he had already modified to fire missiles.
Eventually, as the Cold War ended and more and better satellites were put into orbit, funding began to dwindle for the fastest plane ever. Eventually it was retired and the remaining planes put into storage in the early part of 1990. In 1995, Congress approved $100 million to bring three of the planes back into service, but they didn’t stay for long. In 1998, Congress pulled the plug again and as of now, the remaining aircraft are all earmarked for museums around the country.
While Congress was being wishy-washy about using Habu, NASA was using the four on loan to them for everything they could think of. Eventually, though, even NASA had to put an end to their use of the Blackbird. The last flight of any SR-71 took place on the 9th of October, 1999 at Edwards Air Force Base as part of a public airshow. This brought to an end the active career of the most respected plane in history, but not the legacy.
Now that I have completed my research, I too now have a healthy respect for such a great and impressive plane and just because the full sized versions have been retired does not mean that they have to be forgotten. In fact, reunions are held every so often where one can meet and talk with the people who flew this extraordinary aircraft. And if talking to the pilots isn’t enough, you can join me on the runway as I fly my very own radio controlled model of the SR-71. She might not be able to reach Mach 3.2, but she is almost as impressive to the model community as the real thing was/is to the world.
So while I am sure that I will log many hours of enjoyment behind the sticks of my model, I am sure that somewhere in the back on my mind a voice will whine out “Too bad we aren’t behind the stick of the real thing.” Since it is a pretty sure thing that the real bird will never take to the skies again, that little voice will have to be content in reading accounts written by the pilots who were lucky enough to be one of the chosen few. This is one of my favorite examples from pilot Brian Shul, out of his book titled “Sled Driver”:
I'll always remember a certain radio exchange that occurred
one day as Walt (my backseater) and I were screaming
across Southern California 13 miles high. We were monitoring
various radio transmissions from other aircraft as we entered
Los Angeles airspace. Though they didn't really control us,
they did monitor our movement across their scope. I heard
a Cessna ask for a readout of its groundspeed.
"90 knots," Center replied.
Moments later, a Twin Beech required the same.
"120 knots," Center answered.
We weren't the only ones proud of our groundspeed that day as almost
instantly an F-18 smugly transmitted, “Ah, Center, Dusty 52
requests groundspeed readout.” There was a slight pause,
then the response, "525 knots on the ground, Dusty."
Another silent pause. As I was thinking to myself how ripe a situation
this was, I heard a familiar click of a radio transmission coming from
my backseater. It was at that precise moment I realized Walt and I
had become a real crew, for we were both thinking in unison.
"Center, Aspen 20, you got a groundspeed readout for us?"
There was a longer than normal pause ... "Aspen, I show 1,742 knots".
No further inquiries were heard on that frequency.
Copyright 2006 Mark Gamas
