aviation

The SR-71 Blackbird

The Lockheed A-12 and YF-12A aircraft were the basis for developing the SR-71, also called the “Blackbird” or long-range, advanced strategic reconnaissance aircraft. The 4200th (later 9th) Strategic Reconnaissance Wing at Beale Air Force Base, California, received the first SR-71 to begin service in January 1966. The first SR-71 flight occurred on December 22, 1964. On January 26, 1990, the US Air Force retired its entire fleet of SR-71s.

For almost 24 years, the SR-71 held the record for being the fastest and highest-flying operational aircraft in the world. It could cover 100,000 square miles of the Earth’s surface per hour from 80,000 feet. Two world records for its class were set on July 28, 1976, by an SR-71: an absolute speed record of 2,193.167 mph and an absolute altitude record of 85,068.997 feet.

The fifth SR-71 crewmember to reach the 900-flying hour plateau

Six of the nine years that Colonel (Ret) James H. Shelton Jr. spent at Beale Air Force Base (AFB) passed by piloting the SR-71. He was the fifth member of the SR-71 crew to achieve the 900 flight hour plateau. Though few Habus have reached that milestone, most commercial airline pilots would consider that a paltry amount of flying time.

According to Richard H. Graham’s book SR-71 Blackbird Stories, Tales and Legends, Shelton recalls a special operational Blackbird mission that took place during his initial overseas deployment to Kadena AB in May 1969 with Major Tom Schmittou (RSO):

“The operational tasking from SAC headquarters always had maintenance personnel generating a primary and secondary aircraft. On 13 June 1969, we were in primary aircraft #979 for an operational mission over North Vietnam. It was a typical four-hour flight, consisting of a single east-to-west pass across Hanoi, air refuel over Thailand, then a west-to-east pass just south of Hanoi, returning to Kadena AB.

“The engine start, takeoff, air refueling, and acceleration to Mach 2.8 at an altitude of 77,000 feet went as planned. At the navigation checkpoint, Tom informed me that the navigation system was drifting and the mission should be aborted. Tom made the abort call, and I turned the aircraft back to Okinawa. The descent from altitude and approach for landing was normal. Moderate rain was falling, so I applied the rain remover fluid to the front windscreen, allowing me to see the runway about 2 to 3 miles out.

Cockpit fogging and drag chute deploying

“The touchdown on the runway went smoothly. However, as I retarded the throttles to idle, the cockpit began to fill up with fog (water vapor). I had forgotten to increase the cockpit temperature to 85 degrees or higher, to prevent the formation of cockpit fogging; I remembered one pilot had previously blown the canopy off on landing just to see the runway and I really didn’t want to do that! I quickly flipped the cockpit temperature switch from automatic to manual hot. This eliminated the fog in the cockpit, but did nothing to slow the aircraft down. Being so engrossed with holding the temperature switch in the full hot position (spring-loaded), thereby fixing one problem, I inadvertently created another: I forgot to deploy the drag ‘chute.

“The drag ‘chute must be deployed to slow the aircraft on landing, especially on a wet runway. In my mind, and in actuality, the aircraft was slowing enough. I applied the brakes and the antiskid started cycling like crazy, so I turned it off, but to no avail. I then shut down one engine as I saw the end of the runway coming up very, very quickly (at about 120 miles hour). Fortunately, the runway at Kadena had a cable barrier installed about 1,000 feet from the end, specifically for the SR-71.”

As Graham explains “the BAK 11/12 barrier was installed at two of our operating locations – on runway 16 at Beale and on runway 05R on Kadena. The barrier was designed to stop the plane at a maximum speed of 180 knots. Arming and disarming the barrier was controlled in the tower. At both Kadena and RAF Mildenhall, we had a crewmember in the tower during all takeoffs and landings to make sure everything went smoothly.

Only two successful SR-71 Blackbird Barrier Engagements

“When armed, the barrier was activated by the aircraft nosewheel and main gear as they rolled over pressure-sensitive switchmats located in the runway before the arresting cable. The switches energized a timing computer that caused the arresting cable to be thrown up to engage the main gear struts. On engagement, the arresting cable was pulled out with a relatively constant restraining force to stop the aircraft within 2,000 feet. This was all theoretical. In actual practice, the number of unsuccessful SR-71 engagements far outnumbered the successful ones. Besides Jim successful engagement, I know of only one other.”

Shelton continues. “The barrier is designed to pop up in front of the two main landing gear and stop the aircraft in 400 to 500 feet. The barrier unit uses the B-52 aircraft brake system to slow the aircraft and bring it to a stop (hopefully!). Boy, was I relieved that the barrier worked as advertised! There was one unsuccessful barrier engagement on 10 October 1968 at Beale, where the SR-71 (#977) was destroyed. There were only two barrier engagements recorded at the time, and fortunately, ours was the successful one.

Allowed to continue flying after one of only two successful SR-71 Barrier Engagements

“Well, I just knew my SR-71 flying days were over as I climbed out of the aircraft. This incident terminated my flying at Kadena AB for this tour. The maintenance personnel worked the rest of the day and all through the night replacing the gear doors, hydraulic lines, and electrical wires on the main landing gear damaged by the barrier cable. I owe a big thanks to those maintenance personnel, because the aircraft was ready to fly the next day. They sure saved my six o’clock position (butt).

“Since this was the second fogging incident, Lockheed designed a lever that the RSO moved to stop air from entering the cockpit before landing, eliminating any chance of fogging the cockpit as the throttles were retarded. I call that handle the “Shelton lever.” Needless to say, I was allowed to continue flying, thanks to the thorough flying evaluation the standardization crews administered to me on my return to Beale AFB.”

Photo by U.S. Air Force

SR-71, KC-135Q and JP-7

If not for air refueling, the SR-71 Blackbird’s range would be relatively limited to about 2,000 NM. The aircraft’s range was increased by several air refuelings, reaching the crew’s endurance limit. A few missions have gone above 12,000 NM. The SR-71 and KC-135Q tankers’ forward basing allowed for increased overall efficiency, shorter range, shorter length missions, and faster response.

There were various ways in which KC-135Q crews and their aircraft were different from other Air Force crews. Their boom operators were the only ones qualified to refuel the SR-71, and their aircrews were the only ones qualified for Blackbird’s specific radio-silent rendezvous procedures. The Q-model tankers could transfer JP-4 and JP-7 fuel between different tanks because of the special plumbing between the fuel tanks. They may use JP-4 or JP-7 fuel in their engine. If the SR-71 landed in an area without JP-7 fuel, the Q-model tankers would fly in with the fuel and refill the aircraft using ground-based transfer hoses.

How to get better gas mileage in an SR-71 Blackbird flying at Mach 3

David Peters, former SR-71 pilot, describes how to get better gas mileage in a Blackbird flying at Mach 3.

‘We had some gimmicks we used to make fuel. Each plane was different, but the techniques were very close. As soon as we started the climb away from the tanker, I would select tank two manually and even sometimes go to manual aft transfer to get the CG aft as soon as possible. After leveling off at Mach 3, I would get the CG situated where the trim was at zero for a slight cruise climb thus eliminating induced drag. Next, I would have the aft doors in A position and manipulate the speed to close the forward doors as much as possible without creating an unstart. This might be anywhere from 3.0 to maybe as high as 3.04 or 5.

‘Much of this was dependent on the outside temperature. If it was colder than standard, you could do even better. Hotter than standard not so good but always better than the plan. Using these techniques and a few more I would often see fuel flows below 3600 lbs/hr/per engine at Mach 3. Ed and I rarely came back from a mission with less than 5,000 lbs more fuel than the flight plan called for. There are a lot of those things involved. Flying the SR required a great deal of stick and rudder abilities under some circumstances but I always told people it was primarily a cerebral machine. You had to have a very deep understanding of how it worked to get the job done.’

Skill and knowledge

Peters concludes;

‘I have said many times before, much to the contrary of the engineers, that DAFICS [digital automatic flight and inlet control system] really screwed up what the airplane was capable of just like everything we seem to do anymore, it took the skill and knowledge of the operator pretty much out of the equation. But that is another discussion.’

Check out Habubrats SR-71‘s Twitter profile and Born into the Wilde Blue Yonder Habubrats‘s Facebook page for further Blackbird photos and stories.

Photo by David Peters and TSgt. Michael Haggerty / U.S. Air Force

The Blackbird

Developed from the Lockheed A-12 and YF-12A aircraft, the SR-71, sometimes known unofficially as the “Blackbird,” is a long-range, advanced, strategic reconnaissance aircraft. The 4200th (later 9th) Strategic Reconnaissance Wing at Beale Air Force Base, California, received the first SR-71 to begin service in January 1966. The first SR-71 flight occurred on December 22, 1964. On January 26, 1990, the US Air Force (USAF) retired its fleet of SR-71 aircraft.

For almost 24 years, the SR-71 held the record for being the fastest and highest-flying operational aircraft in the world. It could cover 100,000 square miles of the Earth’s surface per hour from 80,000 feet. The Blackbird’s extraordinary capabilities allowed it to gather intelligence in some of the most hostile environments.

SR-71 Blackbird Mission on the day of the Chernobyl Disaster

Former SR-71 RSO, Lt. Col. Doug Soifer, recalls in Richard H. Graham’s book SR-71 Revealed The Inside Story;

‘Mike Smith and I were TDY for our first time to Mildenhall for our normal six-week rotation. We went to the Det one morning to fly a routine six-hour sortie—the Barents and the Baltic. During the preflight briefings, the intelligence officer said a nuclear power site (Chernobyl) in the Soviet Union had an accident a few hours earlier. They had no other information on it yet. The weather briefing officer gave his normal briefing but also mentioned they double-checked with the weather service at Offutt AFB that we would not fly through any of the fall-out from Chernobyl. With the briefings done and no one concerned about our route of flight, we went to the jet and flew a normal mission.

‘The normal routine after an operational mission is to land and continue to taxi off the runway and directly into the hangar so they could download the mission take. But as we landed and turned off the runway, we were told to stop way before the hangar. We both thought this was very strange and couldn’t understand why we were stopping here. Then one person, and only one, dressed in very funny-looking gear, came walking up to the plane.’

Soifer continues;

‘As he got closer, we could see he was in full chemical gear and had a Geiger counter. After they had guaranteed Mike and I that we were in no danger of through radiation from Chernobyl, they were checking the plane before any of THEM would get close to us! Once he walked about the plane with the Geiger counter, we were allowed to continue to taxi into the hangar.’

Photo by NASA and Unknown