SR71

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

The SR-71 Blackbird

A group of Lockheed members led by Clarence “Kelly” Johnson—then vice president of Lockheed’s Advanced Development Company Projects, also referred to as the “Skunk Works” and currently a part of Lockheed Martin—designed the SR-71, the most sophisticated Blackbird—including the A-12 and YF-12.

Beginning in the late 1950s, the A-12 reconnaissance aircraft—which made its first flight in April 1962 and remained classified until 1976—served as the model for the Blackbird. The YF-12A interceptor variant was first made public by President Lyndon Johnson on February 29, 1964, which was more than six months after it made its first flight. On December 22, 1964, the SR-71’s maiden flight was completed.

The Blackbird was built to reach altitudes of up to 85,000 feet and cruise at “Mach 3+,” faster than three times the speed of sound, or more than 2,200 miles per hour.

Checking out in the Blackbird like a cowboy

Col. David P. Dempster, Blackbird Reconnaissance Systems Officer (RSO) who was also part of the first US Air Force (USAF) contingent to fly operational SR-71 reconnaissance sorties from Okinawa into “denied areas” (the term “denied area” was referred to a specific area over or around a foreign country where you could encounter anything and everything… from MiGs to SAMs), recalls in Richard H. Graham’s book SR-71 Blackbird Stories, Tales and Legends:

“Jim Watkins was a great pilot to be crewed within the Blackbird. A Texas cow-boy who raised horses in his off time, Jim loved, breathed, and lived for flying.

“But, like his horses, he ‘felt’ and handled them with cowboy common sense. Imagine checking out in the Blackbird, a World War II B-24 pilot who flew fighters, transports, KC-97 tankers, and KC-135 tankers at Beale. In tanker, Jim was on the initial OXCART team and provided the air refueling support for the A-12s flying from the Ranch. Jim checked out in the SR-71 like a cowboy putting on an old familiar leather glove!

“We were honored to be among the four SR-71 crews selected to deploy for the first time to Okinawa in March 1968. On 21 March, the first operational sortie flew and the crew encountered a double-engine flameout during descent to their tanker as they exited the target area. After refueling, they returned to Okinawa. A week later the second operational sortie flew, and again, with a different crew and different Blackbird, they encountered the same double-engine flameout at the start of their descent. They landed in Thailand due to the left generator not working. What was happening? Both planes checked out good on the ground after landing and we had lots of jaw-boning among ourselves and with Lockheed tech reps, with no conclusions.

KC-135Q saving an SR-71 over Laos

“Then, on 19 April 1968, Jim and I launched on the third operational sortie (the first for us and Crew Chief Technical Sergeant Bud Martin’s #974). We zipped through the target area with no problems and began the start descent checklist. As Jim pulled the throttle back to the rpm setting called for in our procedures, we had a double-engine flameout. Excitement, adrenaline pumping, and we dropped like a rock into Northern Laos! Jim got both engines started around 30,000 feet, and we headed south. 

“Our [KC-135Q Stratotanker] tanker, the real hero of this story, saw our rate of closure on him stop. He knew what had happened and headed north immediately, unprotected, into enemy territory and rendezvoused with us. Refueling with him, we headed back into Thailand and proceeded to our preplanned end refueling point.

“What to do now? We were scheduled to go back to the target area for another ‘hot loop.’ Over the intercom, I heard this commonsense cowboy say, ‘Dave, I think if when we start our descent, we hold a higher-than-normal rpm we can avoid the flameouts. Want to give it a try?’ ‘Sure,’ I answered. We accelerated back to Mach 3-plus and on course into the target area. We eyeballed adding about 30 miles to the start descent range and when the time came Jim’s theory worked perfectly. No flameouts and a smooth descent.

‘Ichiban,’ the ‘number one’ Habu

“What was the secret and why did this work? The answer turned out to be the way the engine’s fuel controls were programmed. They used standard adiabatic lapse rates, which engineers all over the world assumed depicted the height of the tropopause and outside air temperatures at varying altitudes. WRONG! What we discovered was that in Southeast Asia, the tropopause (and magnificent thunderstorms we would look down on) could go as high as 65,000 feet, rather than the textbook 55,000 feet. Moreover, the air was much colder. Lockheed and Pratt & Whitney Co. eventually reprogrammed the fuel controls correctly and the problem went away. In the interim however, all of the crews adopted the cowboy’s technique and the flameout problems disappeared.

“The day after this flight Jim, Technical Sergean. Bud Martin, and I proudly stenciled the first Habu on the side of #974, which went on to be so successful that it was dubbed ‘Ichiban,’ the ‘number one’ Habu in the 1968 period on Okinawa.”

Photo by U.S. Air Force

The SR-71 Blackbird

The US Air Force (USAF) created the SR-71 Blackbird in the 1960s. It was a plane that could move at a speed that was more than three times the sound made by its own engines.

The SR-71 spy plane held the record for being the fastest and highest-flying operational aircraft in the world for about 24 years. At a speed of Mach 3+, it could cover 100,000 square miles of Earth’s surface per hour while flying at 80,000 feet. Additionally, the Blackbird only needed to accelerate and outrun any missiles in the unlikely event that an enemy attempted to shoot it down.

The SR-71’s engineering was so advanced that new tools had to be created in order to build it.

What it’s like to fly the world’s fastest plane

Spencer Hall spoke with former SR-71 Blackbird pilot Rick McCrary for SBNation to find out what it’s like to pilot the fastest plane in the world.

McCrary explained;

‘You waddle out there in your spacesuit, carrying your little cooler, because it gets quite hot in that spacesuit. You go out to a van with some La-Z-Boys in it, these big recliners, and they drive you out to the airplane. It’s sitting there with all the cables hooked up to it, just like a space launch. It’s outgassing stuff, people are checking it, and then people start unhooking it and leaving and then it’s just you and the crew chief. You get into the seat, close the hatch, and you’re in your cocoon.

‘Startup was also a unique thing. It had this special fuel, because the temperatures during flight got up to over 600 degrees Fahrenheit when you’re at speed. The worry is that with normal fuel, which you want to explode quickly during flight and have a low flashpoint, well… you wanted the exact opposite with the Blackbird. You’re carrying so much fuel that the last thing you want to worry about is self-igniting.

‘You’d burn 80,000 pounds of fuel in about an hour and twenty minutes. That’s a lot of gas. You’re on the boom a lot, and that was why in-flight refueling experience was such a critical part of the screening process. You didn’t have a lot of time to do it, and you had to get it right the first time. Three refuelings were common, but on longer missions, you’d refuel six or eight times. Those were long days.

Last flight on the SR-71 Blackbird

‘You’d light up the afterburner right after that first refueling, and take it to full power for the next hour. That’s pretty amazing, because no other plane can fly in full afterburner continuously. All other planes have either a three-minute limit, or five minute limit on that, but you’d be going at full afterburner for an hour, hour and a half.’

When Hall asked McCrary if he remembered when his last SR-71 Blackbird flight took place, he answered;

‘The answer is kind of an interesting yes and no. There came the time to move on, and we had a good deal. We got to take it to the National Air Show in Washington, DC, and put it on display there. That was going to be our last flight.

Setting 13 acres of Maryland on fire during last flight on the SR-71 Blackbird

‘As we took off from there and came back around for a pass, the right engine exploded. We had to dump gas and set about thirteen acres of Maryland on fire as we did that. That was kind of interesting, just spewing flaming fuel and titanium pieces around.’

McCrary explained that this wasn’t rural Maryland;

‘Actually, we were pointed at the White House out of Andrews Air Force Base. It was funny listening back to the voice tape because I start by saying “Well, we’ll go out over the bay here and dump this fuel.” About thirty seconds later, I say “Screw it” and just dump it. We defoliated southern Maryland, but we got it back on the ground, which was great. After all that happened, I absolutely remember shutting it down. My legs started shaking uncontrollably with the adrenaline from it all when I knew it was over with. My co-pilot never flew again, either.’

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

Photo by Lockheed Martin and U.S. Air Force

The SR-71 Blackbird

The US Air Force (USAF) created the SR-71 Blackbird in the 1960s; it was a plane that could fly at a speed greater than three times the sound made by its own engines.

The SR-71 spy plane held the record for being the fastest and highest-flying operational aircraft in the world for about 24 years. At a speed of Mach 3+, it could cover 100,000 square miles of Earth’s surface per hour while flying at 80,000 feet. In the unlikely event that an enemy attempted to bring it down with a missile, the Blackbird just needed to accelerate and outpace it.

The SR-71’s engineering was so advanced that new tools had to be designed to build it.

Dents on the SR-71 Blackbird Nose

Former SR-71 RSO Richard “Butch” Sheffield (Butch was his nickname because of his haircut that he had back in the 60s) used to point to the nose of the SR-71 Blackbird. He would point to the dimples and say, “This is really important, but I can’t talk about it.”

He would smile.

In the SR-71, he and Bob Spencer executed one of the most crucial missions when they intercepted an SA-5 missile that was flying just inches from the Russian border. Receiving that signal was important to the SR-71’s defense. An SR-71 was never shot down; none ever got close. It was impossible due to defense and speed.

According to former Blackbird pilot Col. Richard H. Graham’s book SR-71 The Complete Illustrated History of THE BLACKBIRD The World’s Highest, Fastest Plane, the nose section allowed the SR-71 to have radar-imaging capability with the advanced synthetic aperture radar system (ASARS), photographic imagery with the optical bar camera (OBC), or a ballast installed. The nose section was held on by faun-massive fasteners.

The Dents that prevented Surface-to-air Missiles from Scoring any Hit on the SR-71 Blackbird

What are those two little dents on the nose of the SR-71 Blackbird?

‘I’m assuming you’re talking about the two “dents” in the chines at the front part of the nose, one on each side? Those aren’t dents, those were put there on purpose for the more advanced ECM systems the Blackbird got in the ’70s and ‘80s,’ says Kelly Pedron, an aviation expert, on Quora.

‘There weren’t any good places to put the ECM receivers in the front of the aircraft, so those “dents” were put in the chine to allow the installation of ECM receivers there. If you’ll notice, the flat part of the “dent” is facing about 60 degrees forward, in order to cover that quadrant of the airspace around the aircraft. Earlier models of the SR, including the A-12, were more concerned with attack radar signals from the rear, so front-mounted ECM receivers weren’t as necessary at the time. With the advent of more advanced Soviet SAM systems, like the S-200 and S-300, a forward warning receiver and jammer were required, hence the development of the so-called ECM “dents” in the nose.’

Pedron concludes;

‘So, yes, those were put there on purpose; nobody accidentally taxied an SR-71 into a solid object.’

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

Photo by Linda Sheffield Miller and U.S. Air Force

The MiG-25 Foxbat

The USSR revealed the existence of the MiG-25 (NATO reporting name “Foxbat”), which looked to be the most lethal fighter aircraft in the world in the late 1960s. This aircraft could outpace any fighter in the air and any other military aircraft except the SR-71 Blackbird.

The Foxbat could reach heights of up to 78,000 feet when equipped with two R-40 missiles (designated by NATO as AA-6 “Acrid”), but it could only reach 68,900 feet when all four missiles were deployed. By contrast, the Habu flew at cruise speeds above Mach 3 at over 80,000 feet.

However, Col. Darrel Cobb himself says in this interview with his son Chris that after an SR-71 Blackbird, he was piloting was fired on by a MiG-25,

The “holy grail” of the soviet air defense system: shooting down an SR-71 Blackbird

‘Operational missions.

‘First, let me assure you; we never broke President Eisenhower’s promise to cease overflying the Soviet Union. We remained over international water – 12 mi offshore.

‘All of my operational flying was from Kadena, Okinawa. Area of interest was Vietnam; Korea; Vladivostok, USSR; China. Later, we flew transatlantic & return from Seymour Johnson, NC supporting the Israel-Arab war. After I left the program, the SR flew from Mildenhall, England & Bodo, Norway.

‘We already touched on missions against Vietnam & the only night mission.

‘Today let’s cover “north missions.”

‘Take off, refuel & head into the Sea of Japan; between Japan & south Korea. Accelerated to operational speed – 3.20. Head directly at Vladivostok. headquarters of USSR air defense; and test/r & d of new radar & intercept development. 2200 mph guaranteed to light up all the radar & intercept systems they had.

‘A MiG-25 interceptor squadron was based just outside of Vladivostok. The “holy grail” of the soviet air defense system was to shoot down an SR-71.

‘Turn north up the Sea of Japan & make a U-turn back down the USSR coast (12 mi offshore) with ELINT & SIGINT recorders going full bore. Photo cameras looking oblique into the USSR, updating the interceptor air order of battle. Head south east till past Vladivostok then turn slightly left then right to cross Korea at the DMZ. Photo cameras updating N. Korea force readiness to resume hostilities against S. Korea.

SR-71 Blackbird fired on by a MiG-25

‘Continue down the Yellow Sea coast of China. All sensors evaluating China’s threat to Taiwan. Turn left- decel & land at Kadena. I flew this profile several times during the 4 years I flew ops missions. One of these got very, very thrilling. Southbound, passing Vladivostok, Reg (my RSO) announced;

‘”We’ve got a fighter locked on – it’s gotta be a MiG-25″

‘”Our DEF [Defensive Electronic Gear, DEF. It Provided ground-to-air and air-to-air missile protection. Still Classified. Def systems were labeled DEF A,B,C,E and G. Later modifications to the DEF Systems resulted in DEF A2, C2, H and M systems. Nearing retirement of the SR-71, a programmable DEF labeled A2C could defeat all known threats to the Blackbirds] is blanketing all beautifully.”

‘”Oops – he just fired – – we’ve got a missile locked on”

‘”Our def has shifted to its missile magic”

‘”There – lock’s broken. Missile’s back in search”

‘”That’s weird – sounds like the missile’s locked on – but not locked on us”

‘”He’s gone – coming up on the “s” turn to the DMZ.”’

Fast forward to late 1976 Col. Cobb retired from the Air Force.

MiG-25 at risk of being shot down by its own missile

Cobb continues;

‘I’m retired! Learning that retirement means no days off; no vacation; no holidays; big pay cut.

‘I find the aircraft TV channel & history channel. Lots & lots of SR-71 films. I avidly watch at every opportunity. In my den, glued to the TV & today’s SR-71 show, & who do I see comparing the MiG-25 with the SR-71??

‘You’re right — Lt. Victor Belenko!

‘He was totally gobsmacked; his MiG-25 burned up the engines getting to Mach 3 yet the SR’s cruise speed was greater than 3.0.

‘Belenko is the one who said that the Holy Grail of Soviet air defense was to shoot down an SR.

‘He told of how they would pre-position ahead of the SR’s radar track and had to zoom up to get a lock on & fire their missile.

‘Belenko stressed how quickly & precisely they had to perform because the window of opportunity was so very short.

‘Their target was traveling at 3600 ft/sec. Faster than a speeding bullet.

‘He described in detail how precise the post-firing breakaway had to be executed to avoid getting shot down by their own missile; talking as though they found this out the “hard way.”’

Cobb Concludes;

‘Man talk about intense attention – – I’m quickly mentally replaying that tape from the inter-phone – –

‘”We’ve got a fighter locked on – it’s gotta be a Mig-25″

‘”Our DEF is blanketing all beautifully.”

‘”Oops – he just fired – – we’ve got a missile locked on”

‘”Our def has shifted to its missile magic”

‘”There – lock’s broken. Missile’s back in search.

‘”That’s weird – sounds like the missile’s locked on – but not locked on us.”’

What happened to the missile fired by the MiG-25 Foxbat at the SR-71 Blackbird?

What happened to the missile fired by the MiG-25? Could it have locked onto the Foxbat itself? Could the SR-71 DEF have deceived it? We’ll never know.

But since the SR-71’s cruising speed was more than the MiG-25’s Acrid missiles’ maximum speed, we might presume that the Blackbird just outran the AA-6. The MiG-25 was unable to carry out a head-on intercept, and there was no chance that a Foxbat could conduct a tail-chase intercept of an SR-71. The Foxbat’s fire control system and radar were insufficiently advanced to handle the challenges of a head-on intercept at closing speeds that would exceed Mach 5.

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

Photo by  Dmitriy Pichugin via Wikimedia and U.S. Air Force