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For educational purposes
The North American Aviation XB-70 Valkyrie was the prototype version of the proposed B-70 nuclear-armed deep penetration bomber for the United States Air Force's Strategic Air Command.
Designed in the late 1950s, the Valkyrie was a large six-engined aircraft able to fly Mach 3+ at an altitude of 70,000 ft (21,000 m), which would have allowed it to avoid interceptors, the only effective anti-bomber weapon at the time.
Engineers had tried to build a supersonic bomber since World War II, and finally completed the XB-70 Valkyrie in 1964.
The North American Aviation XB-70 Valkyrie was the prototype version of the proposed B-70 nuclear-armed deep penetration bomber for the United States Air Force's Strategic Air Command.
Designed in the late 1950s, the Valkyrie was a large six-engined aircraft able to fly Mach 3+ at an altitude of 70,000 ft (21,000 m), which would have allowed it to avoid interceptors, the only effective anti-bomber weapon at the time.
Engineers had tried to build a supersonic bomber since World War II, and finally completed the XB-70 Valkyrie in 1964.
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00:00Transcription by CastingWords
00:30join the quest to go higher and faster than ever before witness the technological breakthroughs
00:45that produce the first supersonic bomber fly three times the speed of sound on great planes the xb-70
00:54this is a united states air force b1b heavy bomber when it was first shown to the public
01:04apart from modifications to the engine intake very few would have noticed any difference between it
01:10and its predecessor the b1a however because of the evolution of technology the b1b in many ways was a
01:19very different aircraft indeed from its predecessor
01:35the a model was to fill the long overdue requirements for a new american heavy bomber however due to
01:42political more than technical problems the project was cancelled but over the next several years rockwell
01:48its manufacturer and the air force revised the aircraft's parameters
01:58now taking full advantage of the aircraft's swing wing potential rockwell developed an aircraft that
02:04could fly long ranges extremely low levels to avoid observation by enemy radar
02:18many of the differences between the a and b models can be found in various forms of detection evasion
02:28electronics so this potent weapon is able to fly quite literally unobserved into the heart of enemy territory
02:36there is one other major distinction between the a and b model and this is simply that the latter model although the product of much considerable technical innovation and several years of additional development is in actual fact slower than its predecessors
02:43simply because an aircraft that could not be seen does not need to have the extra advantage of speed
02:50however this was not always the case
02:57and virtually throughout the history of aviation the quest was for faster and still faster aircraft
03:04probably the biggest single step forward in the search for new technology to gain higher speed came with the adventure of the aircraft that could not be seen
03:11the biggest single step forward in the search for new technology to gain higher speed
03:16And virtually throughout the history of aviation, the quest was for faster and still faster aircraft.
03:28Probably the biggest single step forward in the search for new technology to gain higher speed came with the advent of the jet engine.
03:35But although it was to be pre-war Germany which first utilized jet power, American engineers employed the concept on experimental aircraft way before the war's end with aircraft like this Bell Aero Comet.
04:05The first major development of the post-war years was the record-breaking Bell X-1 rocket-powered experimental aircraft.
04:25Dropped from a Second World War bomber on December 9, 1946, in the hands of test pilot Chuck Yeager,
04:32it was to break the sound barrier for the first time.
04:38The continuing development of the rocket plane produced the X-2, still faster and higher than any of its predecessors.
04:46This experimental aircraft also was to rely upon aerial launching from a heavy bomber.
05:02The quest for higher speed put phenomenal stress not only on aircraft but also on their pilots.
05:20The risk of even a minor malfunction at the speeds now being attempted was enormous.
05:27And the sensations that every pilot carried with them, as they would constantly be required to keep increasing speed,
05:33are something that they alone could experience.
05:35The impact of the vessel includes a special pleasure of the fact that everyone alone could experience.
05:37The force for the sailors to the Germans and the Germans,
05:42the sailors to the Germans and the sailors to the pilots and the sailors to the pilots and their pilots in their Podocats were allowed to escape the energy.
05:52Our first release is due in following a number of the soldiers who were thrown at the fleet,
05:55Much of the data gathered by X-plane tests was to be used for military objectives, because
06:13with the technology of the day, the faster aircraft were the less vulnerable, and therefore
06:18more effective.
06:19By the middle 50s, the American Strategic Air Command was deploying its first all-jet
06:31long-range heavy bomber in the form of Boeing's B-52 Stratofortress, a giant plane with eight
06:38jet engines suspended below fully swept wings, which enabled this aircraft to fly at speeds
06:44in the order of 600 miles per hour, and with great payload.
06:59But although the B-52 was to prove one of the major successes of post-war aviation, its
07:05speed was nothing like the X-planes.
07:20The next major step in the quest to increase the speed of bomber aircraft came with the
07:25B-58 Hustler.
07:27This was a delta wing concept developed by Convair to produce a bomber aircraft which could actually
07:33fly at and sustain supersonic speeds, but to obtain this performance, the plane was relatively
07:40small and could only be classed as a medium bomber.
08:00During the early 50s, and the Cold War was at its height, SAC perceived the need for a bomber
08:06at least as large as the 52, and with a speed still faster than the Hustler.
08:12To achieve this hitherto unthought of speed, with such a large aircraft as a heavy bomber,
08:18would require a phenomenal power source.
08:21And temporarily discarding normal jet power as being inadequate, American aviation engineers
08:26looked towards two alternatives.
08:34The first was nuclear power, used successfully to propel submarines.
08:39At that time, nuclear power was considered as a possibility to propel a long-range bomber.
08:45To this end, Convair converted a conventional B-36, not unlike this one, to actually carry
08:52aloft a fully commissioned nuclear reactor.
08:55The crew was successfully insulated by lead shielding, and although no attempt was made
09:00at this stage to transfer power to propel the aircraft, tests were carried out in earnest.
09:13And various designs were put forward for bombers which would at least in part be nuclear powered.
09:19However, the biggest problem here was nuclear ramifications of an aircraft crash over populated areas.
09:29Another alternative for the requirement by SAC were various proposals to carry large amounts
09:35of so-called ZIP fuel, such as boron, which would be consumed in copious quantities.
09:41Prior to the plane making its final dash, its enormous fuel tanks would be dropped, allowing
09:46a lighter aircraft to make the attack.
09:49But a far more novel approach to attacking the problem came from North American Aviation,
09:54which used a concept of compression lift.
09:58The plan provided for six enormous jet engines contained in a tapered shape under the aircraft,
10:04thus forcing air away from the centre section at high speed.
10:08The design also allowed for this air to be trapped by the outer edge of each wing when it was
10:13lowered.
10:14The compressed air would act to lift the aircraft and help propel it at a speed three times that
10:19of sound.
10:21The XB-70 design was accepted by SAC in December 57.
10:27Wings will return in a moment.
10:32And now we return to Wings.
10:38North American had a long string of successes, including a recent solution, the Navy's need
10:43for a supersonic strike bomber.
10:45By providing the twin engine vigilante, this aircraft was to combine in a small area speed
10:51and bombing capacity never previously made available for carrier use.
10:56But now, having put forward the compression lift concept for a bomber, North American's big
11:02problem was heat.
11:04Wind tunnel tests proved the theory could work, but produced such heat as to warp all previous
11:09conventional materials.
11:12To tackle the problem, North American would employ a honeycomb sandwich material made from
11:17stainless steel.
11:18It offered strength and dissipated heat through its honeycomb structure.
11:23The availability of this technology was fundamental in dealing with the problem of heat caused by
11:28speed.
11:36After twelve months of testing designs and mockups, an order was placed for one XB-70.
11:43But the aircraft, now called Valkyrie, was in for a stormy time.
11:49Two years after accepting the concept, financial pressures obliged the government to limit production
11:54to the one prototype.
11:57And although the following year, extra funding was made available for the program, the Air Force was
12:02having trouble holding onto its supersonic heavy bomber.
12:06The final blow came with the newly appointed pragmatic defence secretary, Robert McNamara,
12:12who redefined the XB-70 as a high-speed research project and limited production to just two aircraft.
12:20But at least the concept was still alive, and its proponents hoped it still might ultimately
12:26be accepted for military use.
12:28In 1963, at least one aircraft was well underway.
12:56The problems with dealing with new, strong metals are sometimes solved by chemical milling, using
13:06acids to shape what machines could not.
13:10Sealing the massive fuel tanks would always prove something of a problem, and especially
13:14on the second prototype, elaborate precautions were taken involving engineers being sealed up
13:20in fuel tanks, which were then pressurised so that a solution could be applied to welds,
13:25to test for flaws which might otherwise escape detection.
13:28The test for
13:46are
13:58¶¶
14:26Slowly, as the months passed, the components came together.
14:41At this stage, the wings were ready for welding to the main fuselage.
14:45And after this was completed, every inch of the join was x-rayed for strength.
14:50With equipment like so much of the Valkyrie project, it was especially developed for the one task.
14:56¶¶
15:06¶¶
15:11Now the massive craft, arguably the largest aircraft ever designed, was taking shape.
15:31¶¶
15:32The engineers worked rotating shifts to ensure the aircraft's completion.
15:36But at no time could any shortcut be taken with a plane that was designed to fly as fast as a bullet.
15:43Everything was tested and tested again.
15:46¶¶
15:50¶¶
16:00¶¶
16:06¶¶
16:12When the supporting structures were finally removed,
16:24the first XB-70, serial number 2-0001,
16:29must have presented an awe-inspiring sight for those lucky enough to see it.
16:35But it was not until May 11th, 1964, that the press and public
16:39were given their chance to marvel over North Americans' sleek white wonder.
16:50Brigadier General Fred J. Ascani, who directed the B-70 System Program Office,
16:56described the plane's various features.
17:00Most of the structure in the wings and fuselage is of stainless steel.
17:05These are our now-famous honeycomb core sandwich panels,
17:09and many of the outer skins on these honeycomb panels
17:12are as thin as seven one-thousandths of an inch.
17:16The two-man crew will sit side by side.
17:23The crew station in this position is about 20 feet above the ground.
17:28All of the space aft of the crew compartment is taken up by fuel,
17:33both in the fuselage and in the wings.
17:36Before the XB-70 is poised at the downwind end of Poundale's 12,000-foot runway for its first flight,
17:45numerous ground tests would have to be performed.
17:50Short after its debut to the public, the aircraft was again supported by jacks,
17:55whilst the electrical and hydraulic support systems were thoroughly tested.
18:00To achieve this, at a time when the engines had not been run,
18:05a ground auxiliary unit was employed to provide necessary power source.
18:09Quite's the room for the two Prayers.
18:11To be continued...
18:11...
18:33with this auxiliary power all moving surfaces were subjected to vigorous testing all flight
18:55controls including the forward canards the avalons and rudders were failed tested and tested again
19:02so
19:05so
19:08so
19:11so
19:14so
19:16so
19:20so
19:22so
19:24so
19:26Like so much of the XB-70, the undercarriage which was to support its phenomenal weight,
19:42together with the added stress of landing and take-off, was for the time a unique and
19:47brilliantly designed structure.
19:56The forward twin wheels were conventional enough,
20:25but the main support gear would be required to rotate as well as fold the four-wheel bogey
20:31mechanism which would be stored in the limited space available.
20:36And the whole process of extension or retraction of this clever but complex gear could be achieved
20:41in a little over 20 seconds.
20:56All of the many and complex tests that were to take place during the weeks before the first
21:01take-off were recorded in a special flight test instrumentation package.
21:05A self-contained airborne unit, the first of its kind which was actually contained in the
21:11aircraft bomb bay, and remained with the aircraft for ground, taxiing and in-flight tests.
21:24One of the final tests the XB-70 prototype was subjected to were vibration tests, designed
21:30to expose the gigantic fuselage and wing surfaces to the effect of vibration far beyond the point
21:37which it might expect to encounter in flight.
21:42VALICID EASY
21:55ORCHESTRA PLAYS
22:01Wings will return after these messages.
22:31And now we return to Wings.
22:39As aircraft tests proceeded, aircrew were introduced to some of the engine's characteristics.
22:45Here at the Arnold Engineering Development Center in Tennessee, a YJ-93 engine was set up, identical
22:52to that which was to be used in the Valkyrie.
22:55It would be installed in a test chamber to give flight crew their first experience of
23:00its enormous power in artificial conditions, similar to that which the crew could expect
23:05in flight.
23:24In here is Al White, North American's chief test pilot, the man chosen to take command
23:30of the XB-70 maiden flight.
23:33With him is Air Force pilot Joe Cotton, who'd be the co-pilot for much of the early test
23:37program.
23:43Another team shown here are Van Shepherd from the aircraft manufacturer and Lieutenant Colonel
23:48Fitzhugh Fulton from the Air Force.
23:50They would represent the backup crew should one be needed.
23:54For months, these men would be embroiled in an extremely busy schedule of learning the techniques
23:58required to fly the world's most advanced and ambitious aviation project.
24:04By early September, most of the exhausting static testing had been completed.
24:09Now the most revealing test would begin.
24:12Tests with aircraft in motion and, ultimately, tests with aircraft in flight.
24:21Before the engines were fired up, the complicated in-flight recording systems would be primed to
24:27record every technical event as it occurred.
24:36This view of the Valkyrie gives a clear picture of what became known as the six-pack.
24:41Tightly gripped together, a phenomenally powerful combination of six mighty jet engines, which
24:46were hopefully to propel the Valkyrie at speeds not many years before considered impossible.
24:54And now, with its own power source available, all of the hundreds of mechanical functions which
24:59have to perform perfectly if the Valkyrie was to succeed, were checked.
25:04As the aircraft was removed from all external power sources.
25:11After a series of taxi runs, pilots and technicians were happy that the Valkyrie was ready for its
25:16maiden flight.
25:21On September 21, 1964, the first prototype of the XB-70A was positioning itself at the
25:41end of Palmdale runway on what was to be a very historic moment for North American aviation and the
25:47United States Air Force.
25:53Here, as planned, White and Cotton were in the cockpit.
26:00At exactly 8.38, the Valkyrie took to the air for the first time in what was to be a series of epoch-making test flights.
26:15This enormous size and unusual shape must have made a breathtaking sight as it took to the air.
26:34Accompanied by a single chase plane, simple routine checks were made as the pilots experienced the waves of the Valkyrie in flight.
26:49One of the first functions was to retract the aircraft's advanced undercarriage.
26:54But here, a problem occurred when the mechanism failed to respond.
27:01Who has opened and stopped is not holding.
27:08OK, they are static. Is that right? They're not moving?
27:12That's correct.
27:15White, with millions of dollars of high technology in his hands, set the landing gear back into its original position.
27:26And all concerned must have watched with unbelievable tension as the gear slowly responded to the cockpit control.
27:34Clearly, the first tests were to be made wheels down.
27:38Nevertheless, an alternative plan was available and the plane continued on its maiden flight,
27:44although one engine was shut down when a warning light flashed.
27:48Still, over 60 minutes of valuable test flight was gained as the aircraft headed towards Edwards Air Force Base.
27:55But one of the rear brakes locked, causing the undercarriage to catch fire.
28:22However, 20 feet above the ground, with the aircraft handling impeccably,
28:27the crew had to be told of the event by the chase plane pilot.
28:31The pilot...
29:00two weeks later the prototype with the landing gear engine and brake problems
29:05all resolved was ready for its second flight on an early autumn morning with
29:17the Sun reflecting on its lower side white rotated test air vehicle number
29:21one into flight on this occasion there were two chase planes so that the
29:27undercarriage retraction could be viewed from both sides as a second attempt was
29:31made to lift the gear in flight
29:42there we go again anxious moments passed as the chase planes crews watched
29:56three lights are out
29:58looks good
30:01now this gear is up and door locked
30:18with the landing gear stowed the Valkyrie can now continue to test at higher speeds
30:25as a plane climbed in altitude a warning light flashed in the cockpit
30:29telling the pilots of a minor failure in one of the hydraulic systems as the plane climbed in altitude a warning light flashed in the cockpit telling the pilots of a minor failure in one of the hydraulic systems
30:36as an automatic precaution white lowered the undercarriage again and headed the aircraft towards an alternative destination to the aircraft
30:41Rogers dry lake which would provide security of an 11-mile natural
31:09provides security of an 11-mile natural runway
31:39the approach was smooth the brakes operated effectively and the Valkyrie made a perfect
31:47landing after the flight it was learned that a fractured pipe had caused the warning lights
31:51to go on but considering the enormous complexity of the aircraft this and the other problems
31:57encountered were hardly unexpected the pilots reported that Valkyrie behaved in a predictable
32:03and comfortable manner clearly they were coming to terms with the world's most powerful aircraft
32:09whilst the first test flights were taking place construction of the second prototype
32:13was proceeding steadily the massive tubular fuselage was married to the six-pack and the
32:19enormous white fins which would give direction to the Valkyrie were already in place for many
32:27of the lessons learned from the construction of the first prototype were rapidly reducing
32:31the manufacturing time of air vehicle two the second aircraft was to differ from the first in a subtle
32:41design change adding an extra five degree dihedral to the wings which was to improve flight stability
32:47here one of the massive wingtips is being fitted this unique feature is still to this day the largest
32:55single moving surface unit to be fitted to an aircraft and their presence would enable the unique compression
33:02lift principle to assist in propelling North American's brainchild into the trisonic stage
33:07back at Edwards air vehicle number one was rising to the sky again
33:15now white cotton and the engineers had gained sufficient confidence to push the Valkyrie up to speeds beyond that of sound on no less than three occasions the plane was pushed into the supersonic
33:44realm and then low to subsonic flight
33:51but doing so stress the aircraft which was designed to be flexible and as a result much of the thick white paint
33:58which cover the aircraft surfaces flaked and peeled away giving the aircraft a model effect but all concerned
34:06would have agreed that it was a small price to pay to get the 70 past the speed of sound
34:12so
34:19However, for this aircraft to reach its projected potential,
34:45it would have to go three times as fast, so tests continued.
34:55Wings will return in a moment.
35:06And now we return to Wings.
35:09October 24th saw the fourth takeoff, and at approximately 40,000 feet,
35:18the folding tips, which had previously never been used,
35:22were lowered to the halfway position.
35:24This would improve the aircraft's stability and reduce the wing drag effect.
35:29And at this stage, Cotton applied full afterburners to the six-pack,
35:33and the slender, white shape of the Valkyrie started its steady increase in speed.
35:39And on the 14th of October 1965, during its 25th flight,
35:44at an altitude of 70,000 feet, with the wingtips fully lowered,
35:48air vehicle number one reached its goal, three times the speed of sound.
35:53But despite its technical success, and complying with all of SAC's requirements
36:15to provide a heavy bomber many times faster than the B-58 Hustler,
36:19the Valkyrie was not destined to be adopted in military service.
36:24The Air Force, knowing the plane would not be accepted as a bomber,
36:28had tried to acquire 150 70s for a reconnaissance role.
36:32But the survivability of high-technical aircraft over enemy space
36:36was in considerable doubt.
36:39Soviet anti-aircraft missillery had effectively brought down the top-secret U-2,
36:44which could fly at heights previously considered safe from any attack.
36:52Missillery also competed with the high-speed bomber concept
36:55within the United States Air Force.
36:57Buried deep in underground control rooms,
37:00SAC's officers were to be given the option of the Intercontinental Ballistic Missile
37:05as far more economical in development, deployment and crew.
37:09And the ICBM was, from the early 60s onwards,
37:13always to be considered the major attack vehicle
37:16with which to deliver nuclear weapons.
37:18The ICBM also allowed the Navy to assert itself,
37:28as its submarines offered platforms which were highly mobile
37:33and could not be detected.
37:35An enormous advantage which the Air Force bombers would not enjoy
37:52until the advent of the B-1B.
37:54But despite its lack of direct military application,
38:03the Air Force testing of the Valkyrie continued,
38:06as the two air vehicles would constantly demonstrate their unique features.
38:10One feature, the crew escape capsule, was a masterpiece of engineering.
38:15Should the Valkyrie depressurise, the capsule's clam-like top and bottom shells
38:20would automatically roll forward and completely engulf the crew member
38:25in an airtight module.
38:27From here, the pilot would still have limited control over the aircraft.
38:31And if it was necessary, the entire capsule could be fired from the aircraft into the air.
38:37These capsules were to play a very important part in the final chapter of Air Vehicle No. 2.
38:44Seen here with its slightly raised wings,
38:47Air Vehicle 2 takes off on a routine test mission on June 8th, 1966.
38:53Al White was in command, but he had a new co-pilot, Major Carl S. Cross, beside him.
39:00Cross was an extremely experienced pilot who'd just joined the 70 project.
39:06At 8.27 in the morning, after testing, the Valkyrie was to form a formation with four chase planes,
39:23and the event would be recorded by an accompanying Learjet.
39:27The exercise was simple enough and should not have presented any problems.
39:31On the Valkyrie's inside right, there was an F-104 flown by test pilot Joe Walker,
39:37who was about to join the Valkyrie test program.
39:40Walker probably had more supersonic experience than any man alive.
39:45He'd just recently completed a flight program of North American still-faster X-15.
39:51This aircraft was the fastest X-plane and was virtually a rocket ship,
39:56which Walker could have flown into space.
39:59Flying below and slightly behind the Valkyrie's right wing,
40:02Walker's F-104 starfighter somehow went too close to the Valkyrie.
40:08This shot, taken from the aircraft on the Valkyrie's left, is here reversed,
40:13to give some indication of what Joe Walker may have seen moments before his starfighter
40:18was somehow to connect with the 70s wing tip.
40:21Possibly it was the vector effect of the giant bomber that pulled the little fighter into its massive wing tip.
40:31In any event, in a matter of seconds, the 104 was hit and rolled into the inverted position
40:37across the top half of the Valkyrie's massive frame.
40:40As it did so, it struck both the 70s vertical fins and the left wing tip
40:45before it was to fall the thousands of feet to its destruction.
40:48Then, with a dreadful shudder, the Valkyrie rolled over and started a steep spin.
40:54Al White reached for the ejection mechanism within his capsule
40:58and was fired out of the stricken aircraft seconds before it was to strike the desert.
41:03His co-pilot was not so lucky and remained in the plane.
41:07Probably the G-forces of the descent stopped his ejection.
41:11By 9.36, air vehicle number two was reduced to a smouldering carcass in the desert.
41:17Over the days that followed, technicians and project officials would examine the wreckage.
41:25But the story was simple enough.
41:27Somehow, the little 104 fighter had accidentally collided with the largest plane in the world.
41:33And on that fateful morning, in one action, America lost two brave test pilots
41:39and one of the only two Valkyries ever to be produced.
41:43Al White, who was the first pilot and had manned more flights of the 70s than any other,
41:48was ultimately to recover.
41:51But he did not fly in the XB-70 program again.
41:54The End
41:56The End
42:28The sole remaining Valkyrie, the first one made, was to continue the test program alone over a period of five years. It was to log 83 test flights. And the research that it and it alone could do would provide valuable information in the United States supersonic transport evaluation and many other projects relating to size, weight, heat and speed.
42:58But in some ways, the Valkyrie had also been a military success. Years later, it was established that the Russians, fearing the potential of the XB-70, had been obliged to commit funds to develop their own smaller version.
43:16But the Soviet fear of the Valkyrie's success was also demonstrated in another way.
43:36For it's now known that it developed a high-performance MiG-25 Foxbat at tremendous expense.
43:43And this fighter's sole function was to protect Russia from bomber aircraft that flew very high and very fast. Aircraft like the Valkyrie.
43:51The paradox was that it seems likely that Russian scientists used North America's vigilante bomber as a pattern for their high-performance Foxbat fighter.
44:05The similarities are just so close, both in size and shape, that it seems certain that Soviet technicians were using American research of the early 50s to protect the Soviet Union from American bombers of the 60s.
44:35Eventually, even the one remaining Valkyrie was to be phased out of test service, and with an F-104 flying a farewell salute.
44:46Air vehicle number one was to land for the last time at Wright-Patterson Air Force Base en route to the United States Air Force Museum.
44:55Piloted by Fitzhugh Fulton and Ted Sturmthal, it was still collecting valuable data, even on its last flight.
45:05Shortly before it was signed over to the museum's curator, complete with its logbook at a brief ceremony.
45:21One of the pilots is reported to have said,
45:24I would give anything to keep the Valkyrie in the air, except pay for it myself.
45:35But although the Valkyrie program had been expensive,
45:47and the cost of the project, divided by the number of flights,
45:51cost American taxpayers $11 million every time it took to the air,
45:55it could be little doubt that North American aviation engineers
45:59had not only achieved a technical wonder,
46:02but had produced one of the world's truly great aircraft.
46:06The Valkyrie program has not brought a number of flights,
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