# XB-70



## ScOoTeR1992 (Feb 20, 2008)

G'day everyone,

i don't know if this was the right spot to put this but anyway, i was wondering if anyone could tell me more about the North American XB-70 Valkyrie I've seen picks and I love the way the wingtips fold down(i think they do anyway). Any information would help thanks.


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## evangilder (Feb 20, 2008)

The sole survivor is at the National Museum of the Air Force at Wright Patterson Air Force Base. There are plenty of sites with good info on the Valkyrie. It was designed to be a mach 3 bomber that could fly higher and faster than the Soviet missiles of the time. Technology developments soon changed that.

I give credit to the Valkyrie for my lifelong interest in aviation. My father took me to the end of the runway at Wright Patterson to see the final landing of the XB-70. I was about 3 at the time and didn't know what it was, but I liked it...a LOT!


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## Henk (Feb 20, 2008)

A great aircraft and would have been a great aircraft if it was ever used, but is was very expensive and after the crash on one of the foto shoots it was the death of the XB-70. They did have a few problems with the aircraft, but you can find it all on a Google search.


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## Matt308 (Feb 20, 2008)

Incredible technology leap for its day both in propulsion and structures. If you do a google search you can read all you want about some of the flight tests that were performed both for the XB-70 program as well as for general highspeed flight technologies. Amazing airplane.


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## Graeme (Feb 20, 2008)

Does anybody have any photos of the escape capsule?


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## syscom3 (Feb 21, 2008)

Some people say it was also one of the noisiest airplanes of all time.


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## Matt308 (Feb 22, 2008)

I've heard a Concorde. Can't possibly be much noisier than that nor any other afterburning airplane.


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## SoD Stitch (Feb 23, 2008)

Graeme said:


> Does anybody have any photos of the escape capsule?



I just happen to have a copy of the Aero Series #30, "North American Valkyrie XB-70A", by Steve Pace, which has pretty good pictures of the escape capsule, both before after ejection. I'll see if I can't scan them this weekend and post them in this thread. Stay tuned!

ScOoTeR, you've come to the right place . . . the XB-70 is one of my favorite aircraft of all time (along with the SR-71, Do 335 and Me 262). You are right, the wingtips did fold down, but only at Mach 1+. For low-altitude supersonic flight, they folded down to 25 degrees; but for high-altitude supersonic flight they folded down to their full 65 degrees. This did two things: during supersonic (particularly triple-sonic) flight, an aircraft's center of lift actually moves rearward, toward the tail of the plane, which normally causes the nose of the plane to pitch downward. In the XB-70, this was countered by removing part of the lifting surfaces (the wings) and, essentially, turning them into vertical stabilizers (the wingtips). The "drooped" wingtips also trapped the shockwave formed by the apex of the lower fuselage, creating "compression-lift", whereby the supersonic shockwave under the wings actually increased the lift, yet decreased drag, dramatically increasing the aircraft's range and speed at altitude. I am still surprised that theoretical SST research hasn't utilized this concept, as it has been proven by the XB-70.


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## Henk (Feb 23, 2008)

Matt308 said:


> I've heard a Concorde. Can't possibly be much noisier than that nor any other afterburning airplane.



I think Matt that the XB-70 was way loader, she had 6 engines. I would like to see the fuel gage drop when you put it full throttle.


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## comiso90 (Feb 23, 2008)

The mother of the MiG25!!


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## Henk (Feb 23, 2008)

comiso90 said:


> The mother of the MiG25!!



He he he...... Well the Mig 25 is also one loud plane, I think the Mig 31 had the same engines and airframe design as the Mig 25, but they only changed a it under the skin compared to the Mig 25. Cold war aircraft is very interesting in how fast and far ahead they were.


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## ScOoTeR1992 (Feb 25, 2008)

thanks Sod Stitch greatly appreciated especially the wings folding down thanks again for the info


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## Graeme (Feb 28, 2008)

'Riding a shockwave' was the brainchild of Alfred J Eggers, an aerodynamicist at NACA who pondered the prospect for trapping airflow underneath a supersonic wing by boxing in the flow between an expanding body underneath it and downturned wingtips...while mowing his lawn in Virgina! 

This gives you some idea of the size of the XB-70. This 'authorised' engineer is walking down the port air intake. 





The escape capsule with 'clam shell' doors sealed when activated maintaining pressure and oxygen during the high altitude portion of the descent. Unfortunately in the fateful crash of June 8 1968 they severely crushed pilot Al White's arm in the process. 
At 15,000ft a parachute was deployed from the capsule. Once on the ground the crew member had access to cold-weather clothing, food for several days and in case the capsule landed in water, it would float like a boat and was equipped with fishing tackle and a life raft.

Similar equipment was carried in the B-58's escape capsule, but the mechanism of closing was different, utilising multiple sliding panes. 





Another hypersonic egress capsule was designed for the Republic XF-103. Looking like a large shoe, one curved panel slid up the dorsal curvature to provide a seal. The final design is illustrated in the middle photo. The bottom photo capsule was built for drop testing. During the drop test it was revealed that the parachute was too small and was ripped to shreds.





(I'm unaware of what protective devices were provided for pilots of the North American X-15 and XF-108 Rapier)


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## SoD Stitch (Feb 28, 2008)

ScOoTeR1992 said:


> thanks Sod Stitch greatly appreciated especially the wings folding down thanks again for the info



I tried to upload those pictures of the escape capsule, both before after ejection, but I kept getting an error message; I'll try again tonight. Sorry!

P.S. This is the best XB-70 website I've found so far:

001 -- Flight of the Valkyrie


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## comiso90 (Feb 28, 2008)

Henk said:


> He he he...... Well the Mig 25 is also one loud plane, I think the Mig 31 had the same engines and airframe design as the Mig 25, but they only changed a it under the skin compared to the Mig 25. Cold war aircraft is very interesting in how fast and far ahead they were.



What I meant was that the MiG 25 was developed specifically to engage the B-70.

A high Altitude mach 3 bomber needs a high altitude mach 3 interceptor.

.


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## davparlr (Feb 28, 2008)

evangilder said:


> The sole survivor is at the National Museum of the Air Force at Wright Patterson Air Force Base.



They have moved the plane to another portion of the base which is in a controlled area. That is where they put the experimental aircraft. You have to get there very early to get reservations to go there. It really bugged me because I wanted my daughter and son-in-law to see the Tacit Blue and we were unable to see it.


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## krieghund (Mar 2, 2008)

Loud? ever been near a tweet!!!


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## Matt308 (Mar 2, 2008)

Agreed. In this case size doesn't always matter.


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## evangilder (Mar 2, 2008)

What makes the tweet seem loud is the pitch. The high screech is painful, but the low rumble of the F-111F or an SR-71 is also deafening.


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## Matt308 (Mar 2, 2008)

Kinda like a 5.56X45mm. The high frequencies just kill the ears compared to 7.62X39mm.


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## drgondog (Apr 14, 2008)

here are a couple of B-70/Al White shots that I finally got around to copying.

The first was early and the second was just before the crash - I think that is Col Cotton next to White.


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## SoD Stitch (Apr 14, 2008)

Nice pics!

If I had those, I'd have them up on my wall in a place of honor.


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## HealzDevo (May 1, 2008)

I have seen a picture of an XB-70 Valkyrie fighter concept but still not sure how it would have worked in practice, considering that most of the planes it was up against it could have just hit with the shockwave...


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