SR-71 Blackbird

KC-135A Crew Chief recalls when his Stratotanker had to purge its tanks of the JP-4 to load JP-7 to refuel an SR-71 Blackbird (No KC-135Q was available)

The SR-71 Blackbird Mach 3+ spy plane could be refueled by standard Stratotankers in the event KC-135Qs were not available.

The SR-71 would be a very short-ranged aircraft were it not for air refueling, limited to around 2,000 NM. Multiple air refuelings extended the range of the aircraft to the limits of crew endurance. Many missions have exceeded 12,000 NM. Forward basing of the SR-71 and KC-135Q tankers permitted faster response, shorter range, shorter duration missions, fewer air refuelings, and greater overall efficiency.

KC-135Q crews and their aircraft were unique from the rest of the Air Force in several ways. As explained by Col. Richard H. Graham, a former Blackbird pilot, in his book SR-71 The Complete Illustrated History of THE BLACKBIRD The World’s Highest, Fastest Plane, their aircrews in fact were the only one certified in Blackbird’s specific radio-silent rendezvous procedures, and their boom operators were the only ones qualified to refuel the SR-71. The Q-model tankers had special plumbing between their fuel tanks, allowing them to transfer JP-4 and JP-7 fuel between various tanks. Their engine could burn transfer JP-4 or JP-7 fuel. Actually KC-135Q tankers could simultaneously carry a maximum of 74,490lb of JP-7 and 110,000lb of JP-4 for their own engines.

This print is available in multiple sizes from – CLICK HERE TO GET YOURS. KC-135R Stratotanker 100th ARW, 351st ARS, 62-3551

If the SR-71 landed somewhere JP-7 fuel was not available, the Q-model tankers flew in with the fuel and, through the use of transfer hoses on the ground, were able to refuel the SR-71.

However, as recently explained [CLICK HERE to read the article] the SR-71 could also be refueled by standard Stratotankers in the event KC-135Qs were not available.

Earl Belz, former KC-135A crew chief told to The Aviation Geek Club;

‘In 1978 I was a Crew Chief on a KC-135A model tanker. We were TDY from Carswell AFB in Ft. Worth, Texas to RAF Mildenhall, UK. While we were there at Mildenhall there was some type of political election or changing of political parties (they were having an election of the Prime Minister or something like that). Because of that, there couldn’t be any foreign reconnaissance (spy) aircraft in England.

This model is available in multiple sizes from AirModels – CLICK HERE TO GET YOURS.

‘There were two SR-71s and one U-2 also TDY at Mildenhall. They couldn’t get a Q model there in time so we were directed to defuel and purge some of our center body fuel tanks of the JP-4 and we were given instructions to load JP-7 in those tanks to support refueling one of the SR-71s (thus separating the JP-7 from our KC-135’s own fuel supply). It’s known as “flying dirty.”

‘We did as directed and took off with one of the SR-71s the following day. We accomplished two refuels. One immediately after getting airborne and a second one about an hour later. I believe the SR-71 was going to Zaragoza Spain to remain overnight at which point it was going to get Q model support to return to Beale. We returned to Mildenhall to finish the reminder of our TDY.’

He continues;

‘I’ve got a couple of photos [shown below] I took while hooked up to the SR-71. Pretty awesome.

‘I took these pictures with my Kodak 110 camera. The one taken from the boom pod has a couple of spots were the photo got stuck to the plexiglass picture frame, but this was the first refuel immediately after we took off. He was moving into position for hooking up. We only refueled it twice. The SR-71 was going to Zaragoza and a Q model was supposedly going to be there the next day.

‘The second SR-71 photo was another one that took off the day before.

‘The third photo was a U-2 that was at Mildenhall at the same time the two SR-71s were there.’

Belz concludes;

‘Sorry about the quality of the pictures but I was just an E-4 Crew Chief.’

Still, we think your photos are beautiful Earl! Thanks for sharing!

Photo credit: U.S. Air Force, Tony Landis Lockheed and Earl Belz

Dario Leone

Dario Leone is an aviation, defense and military writer. He is the Founder and Editor of “The Aviation Geek Club” one of the world’s most read military aviation blogs. His writing has appeared in The National Interest and other news media. He has reported from Europe and flown Super Puma and Cougar helicopters with the Swiss Air Force.

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