Presentation Date: January 27, 2000
BC Thomas
Most hours in the SR-71 Most hours in the SR-71
"We always liked to brag that within 48 hours, the airplane could be over any spot in the earth and take pictures."
It was not an idle boast.
During the Reagan presidency, martial law was declared in Poland, and Soviet tanks and troops began rolling towards the Polish border. B.C. Thomas had just returned from a T-38 practice flight at Edwards AFB when he was told he'd have three hours to catch a military flight for England, and the next day, he'd be making SR-71 flights over the Eastern bloc hot spot.
The Blackbird enabled a President to have manned-reconnaissance an unmistakable physical response to a potential threat to world peace.
It was the fastest. It flew the highest. It documented enemy positions during the Cold War unlike any other reconnaissance vehicle.
The pilot with the highest flight time in that type of aircraft, B.C. Thomas, was the guest speaker at the Golden Gate Wing's January meeting.
Over 11 years and four months, Thomas compiled 1217.3 hours of Blackbird cockpit time. The next closest pilot had 1102. Thomas flew about once a week, because the Air Force rotated missions among ten pilots in the squadron. Generally, flights lasted three-to-five hours, but sometimes ran as long as 10 1/2 hours.
With the decommissioning of the SR-71, most information about the plane, except the reconnaissance imaging and defensive ECM (Electronic Counter-Measures) capabilities were unclassified.
Thomas says the manual on the SR-71 lists a maximum speed of Mach 3.2, unless you had a need to exceed that - - if you thought you were being intercepted or had a missile launch alert, you could push to Mach 3.3. The artificial altitude was 86,000 ft. B.C. knew one pilot who took it to 90,000-plus.
The SR-71 burned JP-7, a highly stable fuel which serving a second purpose of cooling most of the plane's components, and requiring a chemical igniter on engine start-up. Behind the cockpit, the vast length of the airplane's 107-foot fuselage is fuel storage. The skin of the fuselage is the tank, which, when sitting unheated on the ground would leak fuel at a rate of 1000 pounds per hour.. When flying supersonic, the skin warmed to above 650 degree Fahrenheit and expanded, closing the seams.
During the summer, grounds crews would put a tent out over the cockpit area, to keep it as cool as possible before the pilot entered. The pressurized suits, airtight, had their own air conditioning system. The challenge was, once you put the helmet on, you were isolated from your own body. "Of course, as soon as they put the visor down your nose starts itching, "says B.C. "You had a knob that would bring the microphone in and out (closer to or further from the face), to bring the microphone way in and try to get down and...(relieve the itch)." Everything in the cockpit, all the panels and switches, was in close proximity, which Thomas says he really enjoyed.
After about thirty minutes of cruise flight, even wearing the "garden gloves" of the pressure suit, you could touch the window and barely hold it there for 3-4 seconds. Thus, air conditioning, which brought the cockpit temperature down to about 70-degrees. The a/c ran through the fuel to cool, and on missions where fuel got low, the a/c became ineffective, B.C. says, "on one occasion raising the cockpit temperature to 120 degrees. It took another 30 minutes after the plane took on fuel before the temperature returned to a comfortable level."
All the components of the SR-71 required special consideration in design and manufacture. Given the weight of the plane, 130-thousand pounds fully fueled, the tires were about 140-ply and were nitrogen-filled at 650 psi. They were good for eight to twelve landings, and usually changed after eight. That's because the tires were hard as a rock and tended to cut on each touchdown. They required special insulated sleeves in the wheel wells to fend off the tremendous heat of air rushing around the fuselage at Mach 3+. The landing gear strut, of forged titanium, absorbed heat and required cooling for four hours once the plane landed.
Ground crew working around a Blackbird could get a burn they'd unlikely ever forget.
The Blackbird also embodied some of the pioneering elements of stealth technology - - no right angles, a leading edge of baffled plastic to disperse a radar signal and a special pigment in the paint to fend off electromagnetic waves.
Thomas describes a typical reconnaissance mission flight profile as taking off with about 40,000 pounds of fuel, and within 45 minutes climbing to about 26,000 (the optimum altitude) to top off the tanks from 15,000 pounds of fuel to a capacity 80,000 pounds. That bought you almost two hours of flying time. Of course, as Thomas says, "that allows you to fly from California to New York and back. And the best gas mileage is as fast as you can go - - the airplane has minimum drag at 2300 miles an hour."
Refueling speed was about 365 knots indicated, generally about 15 knots faster than a tanker's max speed. The SR-71 flew up to the tanker 2000 feet below it until three miles away, then closed to 1000 feet under the tanker until visual contact was made.
"Refueling was, by far, the most challenging thing I've ever done in my life," says Thomas. "The boom hits well behind the pilot. The center of gravity is just in front of the vertical stabilizer, so you've got a nice long diving board effect. The boom is here, you get the turbulence. This thing bounces in one direction and the cockpit bounces in another. And you can't see what's going on. The only thing you can see is three or four lights of the tanker."
To add complexity, a rendezvous was made under radio silence until the SR-71 and the tanker connected. An interphone could then be used for the two pilots to talk. Add-in a pitch black night, no moon, clouds, icing and occasionally a thunderstorm and you begin to understand the operational intricacies of the world's fastest aircraft.
At mission's end, final approach was 210 knots, plus fuel, and touchdown 185 knots plus fuel, on a minimum runway of 8000 feet. The Blackbird was brought to a stop with the aid of a stock drag chute from a B-52.
"This would give us about a quarter to a half a G of deceleration, which was really nice when the job was to stop the airplane, says Thomas. "The procedure was - - when you felt the main gear touch, you pulled the drag chute handle and one-potato, two-potato, three-potato, wham...! That's when the drag chute would blossom. And an interesting thing is the flight manual said you deployed the drag chute by pulling the handle and jettisoned the chute by pushing the handle. So there was a big paragraph that said when you pull the handle, take you hand away from the handle. You've got three seconds to do it, because your hand is up there and three seconds later everything's going forward... and you just got rid of the parachute."
A typical mission was a takeoff from Beale AFB near Sacramento, to a point just outside the 12-mile limit off Murmansk in northern Russia. There would be in-flight refueling links over Idaho, Goose Bay, Labrador and the North Sea.
Murmansk was a prime candidate for recon missions because subs were refurbished in its harbor. SR-71 radar imaging would show missiles in open launch tubes and aircraft parked in nearby hangars, and neither time of day nor weather conditions mattered.
A 45-degree turn would be made to keep the Blackbird just shy of the 12-mile limit. With a contrail in the cold air at high altitude, "we really didn't make too many bones about being up there," says B.C. Most often there was a bonus 'snapshot' of the Soviet response to a potential airborne threat. They would flash their radar and show their defensive anti-aircraft systems, all actions which could be recorded by U.S. satellites or AWACs planes further offshore.
"I have had indications they've launched missiles at us, but I never saw anything. They would do that occasionally just to see what our response was. Our response was to jam the hell out of it."
One one of his marathon 10 -1/2 hour missions, Thomas' SR-71 lost one of its AC generators. He immediately sought to land, knowing that if the backup generator also failed, the SR-71 wouldn't be controllable. He touched down in Norway.
Thomas had started his "day" around midnight at Beale AFB. He'd planned to beat the summer heat of Sacramento by leaving his apartment air conditioning on until he returned from the mission. So here he was, close to the top of the world in Norway, at five in the morning, waiting for repairs and the tankers to fly up from Beale to refuel. He had to call his landlord and ask if the air conditioning could be turned off.
December, 1964 saw the first flight of the SR-71, with operations beginning two years later. Of the 36 SR-71s built, 18 survived until Congress voted to decommission them because of their operational costs. No Air Force pilot was ever lost in the 18 accidents that claimed as many aircraft. One CIA pilot was killed in an A-11 (the interceptor version), and one Lockheed pilot died in a test determining the airspeed limit versus the SR-71's center of gravity.
Now retired after his second career, flying for United Airlines, Thomas fondly recalls the times when breaking the sound barrier was just part of of an SR-71 driver's workday.
"I remember on television one time, and I've forgotten the dictator's name (Manuel Noriega?), but he was railing over something about the 'imperialist' United States, and as he was talking, there was a double sonic boom."
That indelible mark - - of the most advanced aircraft of its time - - was the favorite sound to B.C. Thomas' ears.