An Up-Close Look at America's Forgotten Supersonic Bomber
The XB-70 Valkyrie was a remarkable machine that was obsolete before its first flight.
North American XB-70 Valkyrie
This is the North American XB-70 Valkyrie, one of the largest and fastest supersonic aircraft ever built. As cutting edge as its technology was, it was obsolete before it ever flew.
Scroll through to learn more about this amazing aircraft and its history.
Higher and faster
The Valkyrie was born in era when it was thought that the best way to penetrate enemy airspace was to fly higher and faster than interceptor aircraft.
North American Aviation
The Air Force wanted an aircraft with the speed of the supersonic B-58 Hustler, but a bomb load closer to the huge B-52 Stratofortress. North American Aviation won the design competition.
Supersonic
Top speed was Mach 3.1, or about 2,056 mph at over 70,000 feet. Few aircraft, even today, could keep up with the XB-70.
Burn
The XB-70 used afterburners to reach its top speed. Afterburners are highly inefficient at low speeds, but they're excellent at Mach 3.
Range
The XB-70 had a range of more than 4,000 miles. Aerial refueling was planned, but the project never got that far.
Wings
Part of the XB-70's supersonic cruise efficiency came from its adjustable wingtips, which tilted down to let the Valkyrie sit on its own shockwave. This increased lift and helped reduce drag.
Crew of 4
The initial design was for a pilot, co-pilot, navigator and bombardier. The latter two positions were eliminated when it transitioned to a research aircraft.
A Different Era
As modern, futuristic even, as the aircraft looks, check out the cars in the background. The car in-between the two trucks looks like a 1953 Ford. On the left is a Ford Country Squire from about 1968.
Cockpit
There are tons of dials and levers to control this six-engine supersonic machine.
Pilot's position
During its short career, only seven people flew the XB-70.
Wingtip controls
Here's a closer look at the wingtip controls.
Looking aft
This is where the navigator and bombardier positions would have been. Behind the camera is the cockpit.
From B to X
President John F. Kennedy canceled the B-70 program in 1961. By that point, the USSR had perfected supersonic surface-to-air missiles that could reach the high-flying XB-70. Two prototype aircraft were given to NASA for testing in the development of larger, supersonic aircraft.
Supersonic tester
NASA flew the XB-70 for just over four years. Here it takes off with a TB-58 chase plane, the trainer variant of the B-58 Hustler. The Hustler was one of the fastest aircraft in the world at the time, and even it couldn't keep up with the XB-70.
As the Valkyrie would fly its test route, the Hustler "cut the corners" to catch back up and fly with the XB-70 until it once again pulled away.
Two 70s
The first XB-70 built had a few issues that led to instability at high speed. These were fixed with the second aircraft built. The majority of Mach 3 test flights were performed by the second XB-70.
Drag chutes
Three drag chutes were used to slow the XB-70 down when landing. They were stored in the upper fuselage, just ahead of the engines.
Unrealized future
The Air Force and North American had grand ideas for the potential of a huge and fast aircraft. Here is an artist's idea for using the XB-70 as a launch platform for orbital and sub-orbital spacecraft.
Nuclear missile launcher
In this version, a lightly modified XB-70 would launch a Minuteman II missile. Typically, these were meant to be launched from fortified bunkers in the Midwest.
SST
Much of the XB-70's NASA testing was to study the possibility of an American-made supersonic transport (SST) to compete with the Anglo-French Concorde and Soviet Tu-144. North American pushed hard for its design, going so far as to add fake windows to an XB-70 during one maintenance period.
Tragedy
This picture, part of a 1966 photoshoot requested by GE, which made the engines for all five aircraft, was taken moments before a fatal midair collision. The orange-tailed F-104 drifted too close to the XB-70's right wingtip, rolled up and over, taking out both of the Valkyrie's vertical stabilizers and exploding in the process.
The F-104 pilot, Joe Walker, was killed instantly. The XB-70 flew for a few more seconds before entering an unrecoverable roll. Pilot Al White was able to eject and survived. Co-pilot Carl Cross could not and was killed.
Retirement
After the crash of the second and more capable XB-70, the original was put back in service for a few years. Lacking the performance of its sister aircraft, it was soon retired. Its last flight on Feb. 4, 1969, was to Wright-Patterson Air Force Base in Ohio. It was then towed on public streets to the National Museum of the US Air Force.
Huge
It's easy to see here how huge the XB-70 is, compared to other supersonic and experimental aircraft.
Big ears
The canards, the small wings just aft of the cockpit, helped maintain control of the huge airframe. Below, the sharp air intakes helped create the shockwave crucial for compression lift.
Adjustable
Not only were the intake's interior walls variable to alter the shockwave at speed, but also the walls were porous to vent turbulent air and help ensure the engines got smooth, supersonic air.
Super-supersonic club
On the lower left is one of the aircraft used for research after the XB-70 was retired: a Lockheed YF-12.
Sharp edges
The lines of the XB-70 are remarkably thin, sharp and straight. Here it looms over a Convair XF-92A at the National Museum of the US Air Force. It was an early delta-wing research aircraft that first flew in 1948.
Big push
The XB-70 featured six General Electric YJ93-GE-3 turbojet engines that provided 28,000 pounds of thrust each.
Lifting bodies
The use of compression lift on the XB-70 led to research on lifting-body aircraft, like the Martin X-24B here.
X united
Check out more photos of the XB-70, along with dozens of other incredible aircraft, over at Touring the Ultimate Aviation Museum: The National Museum of the United States Air Force.
Into the sunset
To learn more about this amazing aircraft, read our full story: Last flight of the Valkyrie: A Closer Look at the Forgotten Mach 3 XB-70 Superbomber.