The Rise and Fall of the XB-70 Valkyrie: A Supersonic Dream Shattered

XB-70 Valkyrie, Things You Might Now Know. The North American Supersonic Bomber That Never Was. A rare interview with General Fred Ascani, the person responsible for the XB-70 program for the Air Force, and a look at the history of the Boeing SST 2707, the supersonic airliner that was also prematurely scrapped.
The North American Aviation XB-70 Valkyrie was the prototype version of the planned B-70 nuclear-armed, deep-penetration supersonic strategic bomber for the United States Air Force Strategic Air Command. Designed in the late 1950s by North American Aviation (NAA), the six-engined Valkyrie was capable of cruising for thousands of miles at Mach 3+ while flying at 70,000 feet (21,000 m).

By the mid-1950s, the United States had developed a state-of-the-art, all-jet-powered bomber force. The newly introduced Boeing B-52 Stratofortesss could reach the Soviet Union from just about anywhere in the world. The soon-to-be-introduced supersonic Convair B-58 Hustler could dash to supersonic speeds. Both aircraft were engineering marvels. But even so, they were expected to perform poorly over Soviet airspace. The B-52 flew too slowly to stand a chance against the latest generation of Soviet interceptors, while the supersonic B-58 lacked the required range and payload to be truly effective. The U.S. Air Force needed a next-generation bomber that would combine the capabilities of both these aircraft. A plane that could fly at supersonic speeds, travel long distances, and carry large payloads.

To meet their new bomber requirements, the Air Force contracted leading aerospace companies to explore radical new technologies, like nuclear-powered jet engines for extending aircraft range and high-energy ‘zip-fuels’ to increase aircraft performance. Boeing and North American Aviation would play a vital role in research. But given the limitations of technology, the most practical solution put forward was the ‘dash concept’ which detailed an enormous aircraft that would travel subsonically most of the way to its target, before jettisoning outer portions of its wings and fuel tanks to make a supersonic dash. These concepts were studied in an era of extraordinary advances in aviation technology and engineering, and by 1957 it became apparent that it might be possible to build a large, long-range bomber that could fly supersonically over its entire mission.

In 1957, the Air Force outlined their specifications for an aircraft that would cruise at Mach 3, up to an altitude of 75,000 feet. It was expected to offer a similar payload and range to the B-52. Boeing and North American Aviation both submitted design concepts, but North American’s proposal was selected for development. A key principle in North America’s design was compression lift, which would significantly improve the aircraft’s lift-to-drag ratio when flying at high supersonic speeds. The new bomber would be designed as the B-70 (XB-70 in experimental prototype form) and named the Valkyrie.

General characteristics

Crew: 2
Length: 185 ft 0 in (56.39 m)
Wingspan: 105 ft 0 in (32.00 m)
Height: 30 ft 0 in (9.14 m)
Wing area: 6,297 sq ft (585.0 m2)
Airfoil: Hexagonal; 0.30 Hex modified root, 0.70 Hex modified tip
Empty weight: 253,600 lb (115,031 kg)
Gross weight: 534,700 lb (242,536 kg)
Max takeoff weight: 542,000 lb (245,847 kg)
Fuel capacity: 300,000 pounds (140,000 kg) / 46,745 US gal (38,923 imp gal; 176,950 L)
Powerplant: 6 × General Electric YJ93 afterburning turbojet, 19,900 lbf (89 kN) thrust each dry, 28,000 lbf (120 kN) with afterburner
Performance

Maximum speed: 1,787 kn (2,056 mph, 3,310 km/h)
Maximum speed: Mach 3.1
Cruise speed: 1,738 kn (2,000 mph, 3,219 km/h)
Combat range: 3,725 nmi (4,287 mi, 6,899 km)
Service ceiling: 77,350 ft (23,580 m)
Lift-to-drag: about 6 at Mach 2
Wing loading: 84.93 lb/sq ft (414.7 kg/m2)
Thrust/weight: 0.314

#aviation #XB70 #valkyrie

[shenmisheshou]

The book "Valkyrie - North Americans Mach 3 Superbomber" is the best aircraft book I have ever read. Nothing else even comes close. Not only does it go into tremendous detail on the design, engineering, production, and testing of the XB-70, it also explores competing designs and the foray into nuclear power for bombers and even the cold war politics and polices. It stands above any other aircraft specific book I have ever read. It is out of print but you can find used copies on line. If you love military aviation, THIS is the book to read.

[anderspedersen]

This airplane alone is worth a trip to the air force museum.

[matthewcuratolo]

I recall a giddy Neil Armstrong interviewing one of test pilots. He seemed in awe of the fact that he flew the XB-70. I thought, "Dude, you walked on the moon"!

[matthewcuratolo]

A half million pounds of stainless steel and titanium, powered by 6 J-93 engines, cruising at mach 3, designed and built by people with slide rules.

[chrisnizer]

Hard to imagine an airplane that large moving at more than 3 times the speed of sound.

[joshuajuarez]

This episode was very cool and good. Good job on this one. Loved it !!! Keep it up

[jenniferwhitewolf]

Bombers not needed? The B52 is on course to be a 100 year in-service delivery vehicle.

[elroyfudbucker]

At 19:13, regarding a nuclear reactor carried aboard a Convair B36; "Tests were carried out in Earnest". Poor Earnest. I hope he survived the tests.

[Discopuss]

1:00:30 John Glenn was NOT the first American in space. That honor was earned by Alan Shepard in 5/61, followed by Gus Grissom in 7/61. Glenn was in fact 3rd, his flight was 2/62.

[EdwardDean-zf]

We have a J-93 on display at GE Aerospace Evendale Ohio

[toddmartin]

Does anything exist of the 3rd xb 70????

[sidefx]

Wonder how many other countries could build this and make it work even today.

[sferrin]

1/4th of a century? Over half a century.

[Steven-pj]

I know that the use of one of these beauties in earnest would be a true nightmare, they are so elegant and beautiful, it fools the eye.

[abitofapickle]

We need a video on the underrated F-105

[tippo]

The SR-71 of the bomber world (or more like the SR-71 being the XB-70 of the recon world)....so far ahead of its time, and such a beautiful aircraft from any angle, and such a tragic loss of AV-2, given the rapidly changing nature of the nuclear weaponised world, that she never ever saw a production life, but wow, what an aircraft regardless...we now may have the B1 Lancer, but she"s not the XB-70!!!!

[Blackburn_Motives]

Would you guys be making a documentary on J.F.K ???

[SliceofLife]

Great documentary(s). I have enjoyed this alot. The XB70 was almost a science fiction story. I read a book about it in the late 70's. I couldn't understand why we didn't keep making them. But I was only 10 at the time. By the 1980's, it seemed that high speed, high altitude, super-sonic bombers would not be practical. It's easier to make a mach 5 missle, than a mach 3 bomber.

[Steven-pj]

I wish to thank you profoundly for using tons as the unit of measure. The traditional measure used, of pounds, is too infinitesimal, requiring a conversion factor.

[fhotrod]

They need to display it with the wing tips down. That is the way she was meant to fly.