The B-47 that flew the largest Nuclear Bomb ever built to Spain

Designed to meet a 1944 requirement, the first XB-47 prototype flew in December 1947, performing far beyond its competitors. It incorporated many advanced features for the time, including swept wings, jet engines in underwing pods, fuselage mounted main landing gear and automated systems that reduced the standard crew size to three.

SR-71 T-Shirts
CLICK HERE to see The Aviation Geek Club contributor Linda Sheffield’s T-shirt designs! Linda has a personal relationship with the SR-71 because her father Butch Sheffield flew the Blackbird from test flight in 1965 until 1973. Butch’s Granddaughter’s Lisa Burroughs and Susan Miller are graphic designers. They designed most of the merchandise that is for sale on Threadless. A percentage of the profits go to Flight Test Museum at Edwards Air Force Base. This nonprofit charity is personal to the Sheffield family because they are raising money to house SR-71, #955. This was the first Blackbird that Butch Sheffield flew on Oct. 4, 1965.

In May 1951 the B-47 began replacing the propeller-driven B-29s and B-50s in US Air Force Strategic Air Command (SAC)’s medium bomber units. While it could carry about the same bomb tonnage as the aircraft it replaced, the B-47’s top speed was more than 200 mph faster.

B-47 Stratojet nuclear bomber

As a result of its capabilities, the B-47 Stratojet became an essential component of the SAC during the 1950s and early 1960s, both as a nuclear bomber and a reconnaissance aircraft.

Since the B-47 did not have the range of SAC’s heavy bombers (the B-36 and later the B-52), Stratojet units regularly deployed to forward air bases around the world on temporary duty, as my father Richard “Butch” Sheffield (former B-47 navigator/bombardier, former B-58 navigator/bombardier and former SR-71 Reconnaissance Systems Officer (RSO)) recalls in his unpublished book “The Very First.”

B-47 navigator/bombardier recalls when his Stratojet flew the largest Nuclear Bomb ever built to Spain
Richard “Butch” Sheffield is on the far right in the photo. His crew was named Best B-47 crew in 1960

Flying to Spain with Mark 36

‘In the summer of 1959, our Wing moved its overseas operating location from Fairford, Royal Air Force Base, in the United Kingdom (UK) to a Spanish Air Force Base at Moron, Spain near Seville.

‘In order to get our nuclear weapons to Spain we just flew them in our B-47’s. This way we did not have to down load them from our alert status in the UK. Our primary weapon was the Mark 36. It weighed twenty thousand pounds, completely filled the B-47 bomb bay and had a seven-megaton yield. This was the largest nuclear bomb ever produced.

‘The normal way of moving nuclear weapons was by Military Air Lift. The weapons were safe, off loaded from the bombers, place into heavy lift aircraft like C-130, C-97 or later, C-5’s.

Carrying the largest Nuclear Bomb ever produced

‘So, flying them in the bomber was very unusual. Also, when the B-47 was full of fuel, with tip tanks fully loaded and the Mark 36 loaded our center of gravity (CG) was far aft of normal. We could not land with the bomb onboard and fuel in the tip tanks. We have to burn the fuel out of the tip tanks or drop the bomb to get the CG forward to land.

‘The route to Moron took us right over the Capital City of Spain, Madrid. As I flew over Madrid with this very large Hydrogen bomb, I could help but think, what do those people on the ground think is flying over them today? We even made a simulated bomb run on them.’

B-47 navigator/bombardier recalls when his Stratojet flew the largest Nuclear Bomb ever built to Spain
Mark 36 nuclear bomb

Flying home over Bermuda Triangle

‘Dad used to have a perplexed look on his face when he would talk about flying through the Bermuda triangle telling me that there really was something strange about it.

‘When it came time to rotate back home to Little Rock, my CO-pilot, Jim McCracken, and I came up with a way to get home sooner than normal. We would land at the Azores; refuel than were going to fly all the way home on one tank of gas going over Bermuda.

‘Everything was going well, right on fuel plans until we passed Bermuda, than we ran into the jet stream, two hundred-knot head winds, that were not forecast. We were lucky to make it to the East Coast. I have never seen, before or sense, headwinds like that. The jet stream never goes that far South.

‘We landed at Hunter, AFB, SC. on the East Coast. Flew home to Little Rock the next day.’

Be sure to check out Linda Sheffield Miller (Col Richard (Butch) Sheffield’s daughter, Col. Sheffield was an SR-71 Reconnaissance Systems Officer) Twitter Page Habubrats SR-71 and Facebook Page Born into the Wilde Blue Yonder for awesome Blackbird’s photos and stories.

B-47 navigator/bombardier recalls when his Stratojet flew the largest Nuclear Bomb ever built to Spain

Photo credit: U.S. Air Force and Linda Sheffield Miller