# XB70 Valkyrie



## Gixxerman (Dec 27, 2011)

I had a look around this part of the site and was surprised this amazing plane has not cropped up here yet.

For my money the Valkyrie, like the Concorde, was one of the most beautiful and striking jets ever to take to the skies.
She was an incredible performer too with a speed of mach 3 at around 78,000ft.
It's hard to believe this is all from around 50yrs ago (1st flight 1964 but obviously design stretching back to the late 1950's).

I recommend the book 'XB-70 Valkyrie: The Ride to Valhalla' by Remak Ventolo for those wanting a deeper look into her.


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## DerAdlerIstGelandet (Dec 27, 2011)

Whats up with the cat?


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## Gixxerman (Dec 27, 2011)

DerAdlerIstGelandet said:


> Whats up with the cat?



Not sure what you mean Chief.....?


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## DerAdlerIstGelandet (Dec 27, 2011)

The 3rd picture is a picture of a cat. 

To be exact, this one...


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## Gixxerman (Dec 27, 2011)

LMAO, now that is funny......I promise, when I previewed my post saw it here 1st it was a Valkyrie.

I shall fix.


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## FLYBOYJ (Dec 27, 2011)

About 100 miles to the north east of Los Angeles, the crash site of 002 can still be accessed.

Crash of XB-70 Valkyrie #002 in memory of NASA Test Pilot Joe Walker and Air Force Maj. Carl Cross


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## Gixxerman (Dec 27, 2011)

Thanks for that FLYBOYJ, interesting new site for me.......and all for a PR shoot, of all things, such a tragic waste.


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## Messy1 (Dec 27, 2011)

It was a remarkable aircraft. Sad that it did not have a more enduring legacy.


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## syscom3 (Dec 27, 2011)

Look at the 2nd picture. There's a P51 on the tarmac. Another fine product built by NAA.


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## Gixxerman (Dec 27, 2011)

syscom3 said:


> Look at the 2nd picture. There's a P51 on the tarmac. Another fine product built by NAA.



3rd pic, surely?

But yes absolutely NAA have a heck of a lot of fine aircraft in their stable and the B1 would be another beauty to my eyes at least.
I always liked the look of the 'companion' mach 3 fighter plane, the F108 Rapier too....






and you can certainly see the family roots in the US Navy's A-5 Vigelante (and maybe a couple of Russian aircraft from the time too?).
Here's somethng I didn't know, the A-5 Vigelante was initially designed with twin vertical tail surfaces, how's that for the XB-70's lineage showing!


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## evangilder (Dec 27, 2011)

I was at Wright Patterson to see the final landing of the Valkyrie when they brought it there for the museum. What a sight, and sound! I will have to dig through the photos I have at home to add to this.


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## Messy1 (Dec 27, 2011)

Please do Evan! Awesome!


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## vikingBerserker (Dec 27, 2011)

Eric, that would be fricken awesome! (btw, I'm officially jealous of you!)


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## evangilder (Dec 27, 2011)

For the record, these are not my photos. I was just barely three years old when the final landing took place. That was the first step on my journey into all things aviation. When they built the current AF Museum, the Valkyrie sat outside for a long time. Thankfully now it is in a hangar.

This is a small sample of the 140 photos I have of the XB-70. Through some of my sources, I was able to get some amazing photos, including the whole photo series of the midair and crash, all the way to the ground impact. I won't post those as I don't think it is appropriate. I will post a few more with some additional facts in the next couple of posts. One thing that I thought was really cool is that for long test flights, the chase aircraft was the B-58 Hustler because of the speed and range. When you see them side by side, you really get an idea of how huge the Valkyrie is.

Notice the first shot is a rare photo of BOTH Valkyries!


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## evangilder (Dec 27, 2011)

You might have noticed the paint in the second photo. Many things were learned about high speed aircraft during that testing. One thing they discovered is that a thick layer of paint was not going to stay on the aircraft, as you can see. What ended up working was a single thin coat of paint. Here is one of the results of a paint job gone bad. Multiple thick coats on the airframe that soon departed at speed! I was happy to get these photos, although I am not sure the engineers who worked on the project are happy that these got out at all. It looks terrible. But it was a lesson learned for later and one that didn't cause any loss of aircraft or personnel, so while it looks bad, it was merely superficial.


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## Gixxerman (Dec 28, 2011)

Ha ha.
Great pics Evangilder, I've seen those paint-stripper pics before, I always wondered just how narked the paintshop boys would have been?


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## Gnomey (Dec 28, 2011)

Great shots Eric! She really is a beautiful aircraft.


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## vikingBerserker (Dec 28, 2011)

I need a cigarette.........


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## wheelsup_cavu (Dec 29, 2011)

Cool pictures of an amazing plane.  


Wheels


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## T Bolt (Dec 29, 2011)

I remember the first time I saw the Valkyrie. I was just out of collage, at the Air Force Museum for the first time. I was wondering around in daze caused by the sight of all those aircraft, taking pictures, and realized that where I was standing was a lot darker than the surrounding hanger. I looked up to see I was standing under the Valkyrie's engines and hadn't realized it. What an unbelievable aircraft!


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## Messy1 (Dec 29, 2011)

T Bolt said:


> I remember the first time I saw the Valkyrie. I was just out of collage, at the Air Force Museum for the first time. I was wondering around in daze caused by the sight of all those aircraft, taking pictures, and realized that where I was standing was a lot darker than the surrounding hanger. I looked up to see I was standing under the Valkyrie's engines and hadn't realized it. What an unbelievable aircraft!


I understand how you feel. Walking through the lobby of the SAC Museum, you walk underneath a SR-71! Still gives me goosebumps thinking about being so close that jet! Awesome! You really feel puny walking under that plane, I am guessing more so with the Valkyrie!


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## evangilder (Dec 29, 2011)

The one that REALLY makes you feel puny is the B-36 in the AF museum.


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## T Bolt (Dec 29, 2011)

It's hard to get a good picture of it now that they've moved it to the experimental hanger. More light in there, but you can't get a picture of the whole thing. Took this shot last year and it still looks like something futuristic. I'll have to scan my old 35mm prints from when it was in the main hanger.


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## Wayne Little (Dec 30, 2011)

Awesome pics Eric...and that shot of yours Glenn


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## Edgar Brooks (Dec 30, 2011)

Years ago, I talked to a man who worked on the aircraft, and he told me that it was known as the "Jesus Plane," since that was the usual reaction to its size, and it was also the saviour of the company.


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## vikingBerserker (Dec 30, 2011)

Great pic Glenn!


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## wheelsup_cavu (Jan 1, 2012)

Cool picture Glen.


Wheels


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## T Bolt (Jan 2, 2012)

I found those old 35mm prints and scanned a few. Even when it was in the big hanger it was hard to get a shot of the whole thing. These pics will give you an idea if the size of it.


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## Matt308 (Jan 2, 2012)

Fookin' 'ell!!!!! What a wonder. I had an opportunity to visit, but work took me away. Curse me.


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## Aaron Brooks Wolters (Jan 2, 2012)

Stupendous photos guys!!!!! Thank you for sharing!


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## evangilder (Jan 2, 2012)

Yeah, with the exception of Glenn's photos, it is difficult to get an idea of the size of the Valkyrie. At 189' long with a wing span of 105', it is huge. But the height (*30'*) is what really makes it look enormous.


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## jipi (Jan 3, 2012)

Thanks to all for these great pictures.


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## davebender (Jan 11, 2012)

The B-36 is huge too. Walking underneath those monsters at the USAF museum was a great experience.


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## Gixxerman (Jan 11, 2012)

The museum in Ohio(?) is one of my must see places.
The big shame. for me at least, is that none of the YB49s survived.
I'd dearly love to see one of those in the metal.


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## Capt. Vick (Jan 11, 2012)

Gixxerman said:


> The big shame. for me at least, is that none of the YB49s survived.
> I'd dearly love to see one of those in the metal.



Amen Brother! Speak the truth!


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## T Bolt (Jan 11, 2012)

The B-35s and B-49s lined up, and the reason there are none at the Air Force Museum. The Secretary of Defense at the time (can’t recall his name) wanted Northrop to merge with General Dynamics. When Jack Northrop refused the B-49 contract was canceled and Northrop was ordered to cut them all up. Very unusual that at least one wasn’t saved for the Air Force Museum which was standard practice at the time. Dirty politics is nothing new.


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## Matt308 (Jan 11, 2012)




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## Gnomey (Jan 12, 2012)

Real shame to see them like that


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## Messy1 (Jan 12, 2012)

X's two Gnomey!


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## Gixxerman (Jan 13, 2012)

I just don't get why they do that sometimes.
Everbody's flying wings had major problems with stability in flight until computers fly-by-wire came good for them, so why were they seen as such a threat to be wiped away so totally?


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## Crimea_River (Jan 13, 2012)

Canada's version of "dirty politics":


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## WJPearce (Jan 13, 2012)

T Bolt said:


> The B-35s and B-49s lined up, and the reason there are none at the Air Force Museum. The Secretary of Defense at the time (can’t recall his name) wanted Northrop to merge with General Dynamics. When Jack Northrop refused the B-49 contract was canceled and Northrop was ordered to cut them all up. Very unusual that at least one wasn’t saved for the Air Force Museum which was standard practice at the time. Dirty politics is nothing new.



The guy you are thinking of was Stuart Symington, Secretary of the Air Force. He wanted Northrop to merge with Convair, which was later bought by General Dynamics. It should also be noted that after being the Secretary of the AF, Stuart Symington's next job was president of Convair.


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## Messy1 (Jan 14, 2012)

WJPearce said:


> The guy you are thinking of was Stuart Symington, Secretary of the Air Force. He wanted Northrop to merge with Convair, which was later bought by General Dynamics. It should also be noted that after being the Secretary of the AF, Stuart Symington's next job was president of Convair.


I remember this story, always wondered the details of all this. Seems pretty fishy to me! I'll have to do some research and refresh my memory.


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## WJPearce (Jan 15, 2012)

Messy1 said:


> I remember this story, always wondered the details of all this. Seems pretty fishy to me! I'll have to do some research and refresh my memory.



I agree, always seemed fishy to me. Sorry to go off topic from the XB-70, one of my favorites. But I think the wings suffered from instability which effected their use as bombing platforms. I think if we were to compare the XB-35 to the B-36 and the YB-49 to the B-47, we might see the wing was not the better ship. So I understand why it would not be selected for production. But I feel all that is a separate issue. Even if the thing was a flaming death trap, not saving one is simply criminal. 

To bring it back to the XB-70, the summary of the accident report for the crash of AV2 is published in Valkyrie by Jenkins and Landis. It basically says that Walker in the 104 would not have a good reference to maintain separation. The report says that the 104 gradually moved out of position and given the configuration of the two aircraft, the XB-70 with its huge delta wing and drooped tip, and the 104 with its high tail, Walker would not be able to see or know that the tail of the 104 was about to hit the tip of the XB-70s wing. Even though Walker was 70 feet to the right and 10 feet below the XB-70, that puts the tail of the 104 into the wingtip of the XB-70. 

To me, the XB-70 is the most awesome aircraft ever to fly, especially for its time.


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## evangilder (Jan 15, 2012)

The final landing of the XB-70 at Wright Patterson was a defining moment in my interest in aviation. Being able to see it fairly regularly until I was about 13 really reinforced that. It was really quite a ground breaking aircraft and a lot was learned from it's testing that was used in later aircraft designs.


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## WJPearce (Jan 15, 2012)

evangilder said:


> The final landing of the XB-70 at Wright Patterson was a defining moment in my interest in aviation. Being able to see it fairly regularly until I was about 13 really reinforced that. It was really quite a ground breaking aircraft and a lot was learned from it's testing that was used in later aircraft designs.



When I was 13 (or so) my dad, uncle, cousin, and I visited the AF museum in Dayton, OH after going to Oshkosh. I need to go back again, but I will never forget the XB-70. I tried to get photos of it but that was nearly impossible because of its size. I think that plane triggers an emotional response for a lot of people. 

A couple more interesting points about the loss of AV2. The photo shoot has been approved by the local commander but had not gone through the official approval process. I think some people were demoted or resigned because of it. Clay Lacy was flying one of his Learjets as the photoship. An SR-71 was in the area and was possibly going to join up if it had the time/fuel after completing its flight (I also remember somewhere stating that this was just a rumor, but I think all parties distanced themselves from the flight after the accident). Curtiss-Wright built the "power hinge" device which articulated the wing tips. There were six of them for each wing. Eight of the 12 were salvaged from the wreckage of AV2 and used as spares for AV1. Even though CW was just a shell of its former self at the time, no longer making aircraft or aircraft engines, I guess they still could make some damn strong parts.


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## johnbr (Jun 20, 2019)

nasa pdf


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## johnbr (Jun 20, 2019)




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## johnbr (Jun 20, 2019)




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## johnbr (Jun 20, 2019)




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## swampyankee (Jun 20, 2019)

WJPearce said:


> When I was 13 (or so) my dad, uncle, cousin, and I visited the AF museum in Dayton, OH after going to Oshkosh. I need to go back again, but I will never forget the XB-70. I tried to get photos of it but that was nearly impossible because of its size. I think that plane triggers an emotional response for a lot of people.
> 
> A couple more interesting points about the loss of AV2. The photo shoot has been approved by the local commander but had not gone through the official approval process. I think some people were demoted or resigned because of it. Clay Lacy was flying one of his Learjets as the photoship. An SR-71 was in the area and was possibly going to join up if it had the time/fuel after completing its flight (I also remember somewhere stating that this was just a rumor, but I think all parties distanced themselves from the flight after the accident). Curtiss-Wright built the "power hinge" device which articulated the wing tips. There were six of them for each wing. Eight of the 12 were salvaged from the wreckage of AV2 and used as spares for AV1. Even though CW was just a shell of its former self at the time, no longer making aircraft or aircraft engines, I guess they still could make some damn strong parts.



There wouldn't have been an SR-71 in that photo shoot; the formation flight was a publicity shot for GE. The SR-71s were propelled by J58s, which were products of Pratt & Whitney Aircraft.


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## johnbr (Jun 20, 2019)

Cutaway net


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## Gnomey (Jun 20, 2019)

Good stuff!


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## johnbr (Jun 26, 2019)

The XB-70 
GE-yj-93 engine


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## Gnomey (Jul 2, 2019)

Nice shots!


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## Zipper730 (Jul 6, 2019)

Gixxerman said:


> I had a look around this part of the site and was surprised this amazing plane has not cropped up here yet.


Actually it has, but not in much detail.

This forum really is kind of about three subjects in one

Aviation: Which divides into...
WWII: The bulk of it
Early aviation to WWI
Interwar
Post War to Vietnam
Vietnam to Present

Food: This is something I've joked about before, but this forum is definitely foodie friendly. The topics usually cover the following
Bacon: We even have a bacon rating, this forum is highly bacon centric. It's not hard to imagine why -- how many people do you know who *don't* like bacon? And I'm not talking about people who eat turkey bacon or some vegan substitute. I'm talking about the flavor of bacon at all...
Sausage
Cheese
Chocolate: Because chocolate makes nearly everything better -- it raises one's mood and all that stuff.

Women
There are some female members, but they seem to be few in number; most members are male and, statistically, more men are heterosexual than otherwise, so there you go...




> For my money the Valkyrie, like the Concorde, was one of the most beautiful and striking jets ever to take to the skies. She was an incredible performer too with a speed of mach 3 at around 78,000ft.


Actually, the engines and inlets were good to speeds well beyond that. The engine was rated for Mach 4 (not sure if that's full tilt, or the normal operating speed), and from what I was told, the designer (Walt Spivak) said the inlets were good for it too. The overall construction was designed to tolerate high temperatures, but the devil was in the details (there were some imperfections in the early skin fabrication), and A/V-1 had a tendency to shed skin on an occasion or two.

I would assume A/V-2 could have done it, though I'm not sure if it ever did.


> I recommend the book 'XB-70 Valkyrie: The Ride to Valhalla' by Remak Ventolo for those wanting a deeper look into her.


That's a good book, I have it. I'd also recommend 'Valkyrie: North American's Mach 3 Superbomber" by Dennis R. Jenkins and Tony R. Landis. It's kind of the authoritative book on the aircraft.



DerAdlerIstGelandet said:


> Whats up with the cat?


Unsure, but that is the secret purpose of the modern internet...


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## Zipper730 (Jul 6, 2019)

Messy1 said:


> It was a remarkable aircraft. Sad that it did not have a more enduring legacy.


Yeah it was, plus it had that a quality that made it look like it came out of science fiction (the F-22 and YF-23 had that quality), in a good way.

It probably would have bankrupted us: I remember hearing some amazing cost figures for the plane.

$22 million: I have reason to suspect terminological inexactitude on that one. It's a practice to sometimes hide parts of a program's funding in other programs as a way of concealing cost. From what I remember, the B-52 costed around $14.4-14.6 million, and the B-58 between $12.4 to 30.1 million. If this figure was, somehow correct, you would need 5.5 billion to cover SAC's 250 x B-70 proposal
$50 million: That figure I heard before, and if so, we'd have needed $12.5 billion to fund the 250 bombers intended
$150-160 million: I was told this figure came from the cost of the prototypes, and other variables that would lead to the lines to produce 250 B-70's. Since I don't know the math, it's pure conjecture. Regardless, to fund 250 x B-70's you'd see $37.5-40.0 billion.
Regardless, when one considers that $450-500 million covered the USS Enterprise (1962-2012?), which was a nuclear carrier so expensive, that McNamara was unwilling to fund any more as long as he remained the Secretary of Defense; asking for $5.5 billion to $40 billion would be like asking for 7.3% - 53% of our current listed defense budget. That said, I'm not sure what the defense budget amounted to back then... still I have a feeling it'd be a big pill to swallow.

If I recall, the arguments against it were as follows

Cost
WS-110: This was the B-70 program
Original requirements: Overall range of 7500 nm, 3000-4000 nm supersonic (Mach 2.0 or faster), at some specified altitude (forgot), with a payload of either 25000 lb., or 10,000 lb. for normal mission, with loads of 25000 lb. over shorter ranges.
Later requirements: Range of 7500 nm, cruise portion to be flown at Mach 3.0 or faster, at some specified altitude (forgot), while carrying 10,000 lb. payload (25000 lb. over shorter distances), in a shirt-sleeve environment (no requirement for pressure-suits, ejection-capsule required). Maximum weight of 500,000 lb., and able to use existing runways and facilities in use by SAC.
Cost $1.85 billion for program including the F-108 Rapier

WS-125: This was a proposed nuclear-powered aircraft
Early requirements: Subsonic cruise on nuclear power; extended dash at supersonic speed using chemical fuel. I forgot what payload and altitude requirements were required, but I wouldn't be surprised if it was similar to WS-110. That said, the design was deemed unfeasible.
Later requirements: Cruise to be supersonic (forgot payload and altitude requirements), navigation systems the same as WS-110. It seemed the program was given new life because the USAF, in an effort to embarrass Flight-magazine (at minimum -- part of me suspects it was also to create a requirement for the aircraft -- the Cold War was basically one of the world's biggest and most expensive dick waving contest), published them some bogus information about the M-50 being a nuclear powered bomber. When it was released, it became a Cold-War issue (whether by intent or not), for dick-waving rights.
Cost: $2.05 to 2.1 billion.

Basically: It wasn't just the XB-70 program, it was WS-125 as well.

Enemy Missile-Defenses
The SA-2 managed to get a substantial fear-factor over it's ability to shoot down the U-2
I assume part of this issue was an argument to avoid having to fund the B-70, more than the actual capability of the SA-2. Remember the cost would have made a lot of people look for an "out", and the argument matters more than the facts in legal and political matters (that's all I can say, there's a no-politics rule on this forum).
SAC had proposals for high altitude penetrations into the USSR as late as 1962 (though I assume a sizable number would be done as nap of the earth, or NOE).

There were some new SAM's that appeared to be able to shoot-down a high-speed bomber like the XB-70, some either had or appeared to have ABM capability.
The SA-5 Griffon was suspected of being an ABM: At least one of the proposed developments was a work of disinformation
The SA-5 Gammon was capable of shooting down high speed, high altitude targets
The XB-70 was designed to carry a defensive-missile capability for use against fighters and SAM's: The best contender was a lenticular (disc-shaped) weapon that could supposedly reach 250g at as little as Mach 3.0, which basically means that...
You'd get a turn-radius of 1048.8-1155.2' (319.7-352.1m), and a turning-circle of 6589.6-7258.6' (2008.5-2212.4m), based on the speed of sound at 25000-75000'.
For comparison, an F-15 flying at Mach 0.72 on the deck in a sustained 9g turn, you'd see a turn-radius of 2231.4' (680.1m), and a turning circle of 14020.3' (4273.4m).
That said: If the missile was racing along at Mach 8 (same g-load), you'd get a turn-radius of 7457.9-7215.1' (2273.2-2504m), and a turning circle of 46859.4-51617' (14282.7-15732.9m); at 25000', you'd probably see an F-15 doing a radius around 2931.3-3407.2' (893.5-1038.5m), and a circle in the ballpark of 18418.2-21408.2' (5613.9-6525.2m), so it could probably shake it loose. Consider that the primary threat would be missiles which don't take evasive action, and supersonic interceptors.

There was a proposed lenticular missile that could be used as an ARM, which would probably be more useful.
While the initial XB-70 proposals had a single bomb-bay, it was quickly amended to a two bays of equal size, making possible the carrying of up to 50,000 pounds of ordinance (by volume, at least); as time went on, the forward bay was reduced to a smaller size (capacity was 10,000 lb., so both bays would provide a total load of 35,000 lb.) due to the cancellation of the zip-fuel program (they actually had contemplated removing one of the bays entirely, but the addition of JP-6, which burned more cleanly, combined with various aerodynamic refinements, made it possible to fit a smaller bay); as time went on, they eventually were able to recover most all performance (a redesigned canard, more room for fuel in the wing-tips), and eventually were able to restore the original bomb-bay size, but instead of two bays, each able to carry 25000 lb. of ordinance, it was now one HUGE bay that could carry 40,000 pounds (not sure why the weight reduction, by volume, you'd expect 50,000), and that would allow respectable room for ordinance. Remember, there are bombs that are not just heavy, but BIG.


Ballistic-Missiles
The argument was that manned bombers were obsolete, and ballistic missiles were the wave of the future
For some time they actually were looking into cruise and ballistic missiles (for intercontinental use), but for the most part, it seemed that Sputnik kind of resulted in a favoritism towards ICBM's. That said, they were fast and hard to shoot down (and the cost of just one getting through are catastrophic); that said, there was the SLAM/Pluto project which involved a nuclear powered ramjet engine (direct cycle), which could carry one warhead, or carry a bunch of smaller ones (sanity, fortunately prevailed).
Ballistic missiles are not recallable: Any self-destruct mechanism used for tests would probably be removed for actual operations as the enemy would be able to trigger it and stop our missile without even firing a shot. Admittedly, I'm not sure how many bombers would return if they received the orders to abort their attacks, as they could perceive it as being a spoofing-attempt (something which has happened in WWII when the costs were actually far lower).
Ballistic missiles generally lacked the accuracy required for conventional ordinance delivery: Even if they did in those days (they do now -- some can pull off a CEP of around 400 feet, which was the same as a B-17), they could only be used once, whereas bombers can be used repetitively (while there were some cruise missiles that could land, the only one I recall that could separate payload from the rest of the missile was the Snark, and once that happened, landing might not be possible as the CG would be thrown so badly out of alignment). The enemy would not be able to necessarily distinguish a nuclear weapon from a conventional one, all they could tell is a weapon is racing over the pole at an ungodly rate of speed, and they would probably be more likely to fire their nuclear weapons than take the risk.

We assumed the USSR would abandon manned bombers and just develop ICBM's: They largely did, but not totally. This belief lead to the cancellation of the F-108.
In order to save money, the F-108 was sharing funds with the XB-70: It looks good on paper because for about $350 million extra dollars you can procure two aircraft instead of one; furthermore, the plan was for 450 F-108's.
The problem is when it was cancelled, it basically made the XB-70 seem grossly more expensive (which it sort of was)


Ultimately, it was extremely expensive and would have looked for nearly any alternative than having to follow the current pattern of spending ever more money.



Gixxerman said:


> I always liked the look of the 'companion' mach 3 fighter plane, the F108 Rapier too....


And, if the Standard Aircraft Characteristics' Sheets are accurate, it would have had good maneuverability: The aircraft's stall speed was around 119-128 kts (these were the latest ones) and that's actually quite good. Better than the F-4 (152 kts).


> and you can certainly see the family roots in the US Navy's A-5 Vigelante


NAA seemed to kind of use lots of cross-pollination. The LRIX/WS-202 (later F-108) had the all moving tail it seemed before the XB-70 did (the XB-70 originally had twin-tails with normal rudders). The A3J/A-5 had twin tails at first, but they weren't all moving AFAIK


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## Zipper730 (Jul 13, 2019)

Just to be clear, despite a lot of criticism of the XB-70, I do think it was an amazing aircraft with a lot of capability.


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## Zipper730 (Jul 21, 2019)

WJPearce said:


> The guy you are thinking of was Stuart Symington, Secretary of the Air Force. He wanted Northrop to merge with Convair, which was later bought by General Dynamics. It should also be noted that after being the Secretary of the AF, Stuart Symington's next job was president of Convair.


I didn't know he became the President of Convair. I do know that one of the early Secretary of Defenses sat on the Convair board.


> Sorry to go off topic from the XB-70, one of my favorites. But I think the wings suffered from instability which effected their use as bombing platforms.


The first and second prototype, in some ways were very similar in handling; they did have some significant differences in other ways.

Similarities
Both aircraft seemed to be stressed for similar g-loads: According to a Jenkins/Landis' book on the XB-70 (largely considered the authoritative book), as well as another book I have on the design, there were simulator tests done to evaluate vibration loads to the pilots for gust-loads. Since, it seems unlikely that they would simulate for conditions the plane couldn't take, it seems likely that 6-7G was entirely possible (probably at combat weight, which is around 300,000-350,000), though it produced some vibrations that were highly unpleasant to the pilot (by highly unpleasant, I mean it caused a feeling of pressure in your chest). At high altitudes, 3G was entirely possible. Not sure about 3.5G.
Both aircraft seemed to have similarities in control (dis)harmony: Aileron forces were fairly light, and roll-rates were fast, and felt fighter-like; elevator loads were heavier and felt more bomber-like; supposedly rudder loads were similar to elevator loads.

A/V-1 (62-0001 / 20001)
Handling
The aircraft had poor directional stability, which usually resulted in the pilots lowering the wing-tips partially down at M=0.75 instead of M=0.9, and all the way down at M=1.4 instead of M=2.0.
Roll-stability is poor at higher speeds, which has to do with the lack of dihedral.

Configuration & Systems
The aircraft's construction had some defects in honeycomb construction: It had to do with the fact that, as they began constructing it, they made various errors. Some were caught, others managed to escape detection, and this resulted in a Mach 2.5 limit to the aircraft. At a later period, there were some fixes made to some of the honeycomb panels, which might have allowed a performance increase (there were some descriptions of the aircraft outrunning a B-58).
There was also a miscalculation in the wing apex's structural load-bearing capacity, and this resulted in a failure of the apex, which damaged all six engines.
The aircraft didn't have any significant dihedral to it's wings
The wing-fold mechanism included 3-settings: Up; 25 degrees down; 64.5 degrees down
The A/C lacked an automatic inlet control system as built
Two of the fuel-tanks were inoperative: During the construction of the aircraft, they pressurized the tanks with gas to identify any possible signs of leakage. Upon detecting leakage, they disassembled the aircraft partially, and used a short term sealant (1000 hours service life) to cover up the known leakage points. Two of the tanks (Tank 5 Left & Right) were effectively impossible or difficult to get inside. So, they simply deactivated them.


A/V-2 (62-0207 / 20207)
Handling
The aircraft was more directionally and roll-stable
The aircraft had adverse yaw as a result of the dihedral, which required firm inputs on rudder, and monitoring the sideslip indicator, as it was possible for large angles to form that weren't always easy for the pilot to detect.

Configuration & System
The aircraft's honeycomb construction was far better designed than A/V-1, as they had largely been able to avoid making the various mistakes, as seen in A/V-1.
The hydraulic and fuel lines were flexible, which handled expansion better
The aircraft had 5-degrees of dihedral: The wing folding mechanism went down an additional 5-degrees (A/V-1: 25 & 64.5 degrees; AV-2: 30 & 69.5 degrees)
The aircraft had an automatically controlled inlet system with manual back-up.





> To bring it back to the XB-70, the summary of the accident report for the crash of AV2 is published in Valkyrie by Jenkins and Landis. It basically says that Walker in the 104 would not have a good reference to maintain separation. The report says that the 104 gradually moved out of position and given the configuration of the two aircraft, the XB-70 with its huge delta wing and drooped tip, and the 104 with its high tail, Walker would not be able to see or know that the tail of the 104 was about to hit the tip of the XB-70s wing. Even though Walker was 70 feet to the right and 10 feet below the XB-70, that puts the tail of the 104 into the wingtip of the XB-70.


While they never explained this, they did see some smoke shoot out of the engine. I'm not sure if it was a compressor stall as they approached the aircraft, or if the engine had a malfunction which distracted General Walker.


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