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North American XB-70

sferrin

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bobbymike said:
sferrin said:
Moose said:
Grey Havoc said:
And to think, this could have still been in service today. :(
Only if missile technology never advanced.
Because it forced the B-52 into retirement right? If the XB-70 had gone into service I guarantee you they'd have found uses for it. Supersonic, gliding JDAMs comes to mind. Or SRAM, ASALM, etc. (Yes, yes, I know TODAY'S JDAM doesn't fit that description.)
If it evolved like the B-52 and B-1, Mach 3 CAS would be interesting :eek:
I'm thinking more like 25,000lbs of GPS guided munitions gliding in from Mach 3 and 75,000 feet for an Operation Iraqi Freedom kickoff. Would not be good for the "bomb truck loitering over the battlefield" missions B-52s and B-1Bs fly. It would certainly be a significant improvement in reaction time over today's bombers as well.
 

GeorgeA

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Well given it's flight regime, it might not have the longevity that the BUFF has enjoyed, but then again had it gone into production, it would have been improved in a number of ways, including structurally.

With standoff weapons (ASALM or something Skyboltish) it would have been a formidable weapon, and as I've suggested before, a modern analog would be a pretty impressive Pacific pivot/anti-A2AD system.
 

TomS

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Grey Havoc said:
And to think, this could have still been in service today. :(
Not likely. Even if it had been successfully brought into service, it would have been so expensive and so ineffective against modern air defenses that it would have gone away by the 1980s.

The B-52 survived because it was adaptable to low level penetration and later as a cruise missile carrier. The B-70 would not have worked down low at all and would not have made economic sense as a cruise missile platform.
 

Orionblamblam

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Had the B-70 gone into production and service, a few things seem likely:
1) No B-1 bomber, certainly not on the Real History schedule
2) the B-70 would have been blisteringly expensive

So the USAF would have had the B-52 bomb truck and the terribly expensive B-70 fast-reaction vehicle. It seems likely that the USAF would have made efforts to reduce the cost of operations of the B-70, so that would be a good thing. Additionally, the *only* advantage that the expensive, RCS-the-Size-of-Mt.-Rushmore B-70 brings to the table is speed. So... when it flies, it probably generally flies fast. So there'd be a lot of experience with giant supersonic aircraft. This would aid not only in the design of followon giant supersonic aircraft, but also provide experience in *how* to operate giant supersonic aircraft - as in how to fly supersonically over the CONUS without the sonic boom being such a problem. So... *perhaps* the SST program actually comes to fruition sometime in the 70's.

And *perhaps* that's what replaces the B-70 by the 1980's... a "B-1" or "B-71" that is derived from the SST, which itself was aided along by the B-70. Boeing did have concepts for bomber versions of the 2707-100, so maybe...
 

bobbymike

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Orionblamblam said:
Had the B-70 gone into production and service, a few things seem likely:
1) No B-1 bomber, certainly not on the Real History schedule
2) the B-70 would have been blisteringly expensive

So the USAF would have had the B-52 bomb truck and the terribly expensive B-70 fast-reaction vehicle. It seems likely that the USAF would have made efforts to reduce the cost of operations of the B-70, so that would be a good thing. Additionally, the *only* advantage that the expensive, RCS-the-Size-of-Mt.-Rushmore B-70 brings to the table is speed. So... when it flies, it probably generally flies fast. So there'd be a lot of experience with giant supersonic aircraft. This would aid not only in the design of followon giant supersonic aircraft, but also provide experience in *how* to operate giant supersonic aircraft - as in how to fly supersonically over the CONUS without the sonic boom being such a problem. So... *perhaps* the SST program actually comes to fruition sometime in the 70's.

And *perhaps* that's what replaces the B-70 by the 1980's... a "B-1" or "B-71" that is derived from the SST, which itself was aided along by the B-70. Boeing did have concepts for bomber versions of the 2707-100, so maybe...
A giant Wild Weasel? ;D A couple dozen B-70's flying high altitude at M3 towards the USSR (or China today, maybe Iran) EVERY radar lights up for hundred of miles to be targeting by VLO aircraft loaded with AARGM flying lower??
 

XP67_Moonbat

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2707-100 bomber variants? No you're just teasing us, Scott! ;D Future APR, maybe? Huh, huh? :)
 

LowObservable

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NGC (and to some extent LMSW) were quite enthused by M=2.4 bombers in the early 2000s.
 

Orionblamblam

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XP67_Moonbat said:
2707-100 bomber variants? No you're just teasing us, Scott! ;D Future APR, maybe? Huh, huh? :)
It's coming. Unlike a lot of projects, the 2707-100 (and 200, and 300) is very well documented, so perversely the diagrams are that much more challenging to create.
 

Moose

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TomS said:
Grey Havoc said:
And to think, this could have still been in service today. :(
Not likely. Even if it had been successfully brought into service, it would have been so expensive and so ineffective against modern air defenses that it would have gone away by the 1980s.

The B-52 survived because it was adaptable to low level penetration and later as a cruise missile carrier. The B-70 would not have worked down low at all and would not have made economic sense as a cruise missile platform.
Very well put.
 

sferrin

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TomS said:
Grey Havoc said:
And to think, this could have still been in service today. :(
Not likely. Even if it had been successfully brought into service, it would have been so expensive and so ineffective against modern air defenses that it would have gone away by the 1980s.
Sure, if you insist on the narrow view of dropping gravity bombs over a target.

TomS said:
The B-52 survived because it was adaptable to low level penetration and later as a cruise missile carrier. The B-70 would not have worked down low at all and would not have made economic sense as a cruise missile platform.
Why would anybody even consider launching subsonic cruise missiles from a Mach 3 bomber? Now, on the other hand, how many ASALM or SRAM2s could you fit. And did it have external carriage capability like those drawings one sees floating around of it carrying a pair of Skybolts externally? I imagine a Mach 3, 70,000 foot launch would give a Skybolt a bit more range than a subsonic launch from a B-52.
 

LowObservable

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Ben Rich reckoned that SRAM would go 500 miles off an SR.
 

TomS

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Rich is sometimes full of it. SRAM had a range of around 100 miles from high altitude and a subsonic launch. Five times the range just because of a Mach 3 launch? No way.
 

sferrin

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TomS said:
Rich is sometimes full of it. SRAM had a range of around 100 miles from high altitude and a subsonic launch. Five times the range just because of a Mach 3 launch? No way.
Orbital gives it at closer to 200 miles though it doesn't state the launch conditions. With over triple the launch speed and nearly double the altitude in a ballistic flight path? 500 doesn't sound impossible.

http://www.xmission.com/~sferrin/SRAM.pdf
 

Abraham Gubler

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TomS said:
Rich is sometimes full of it. SRAM had a range of around 100 miles from high altitude and a subsonic launch. Five times the range just because of a Mach 3 launch? No way.

Its from a slide on the use of an SR-71 as a strike asset. The SRAM is launched from much higher altitude and velocity than from anything else. It would make that range. I'm sure the slides in question are on this forum somewhere and on my hard drive somewhere. But I'm not looking for it, at the moment...
 

TomS

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sferrin said:
Orbital gives it at closer to 200 miles though it doesn't state the launch conditions. With over triple the launch speed and nearly double the altitude in a ballistic flight path? 500 doesn't sound impossible.

http://www.xmission.com/~sferrin/SRAM.pdf
That range is from a lofted trajectory as a SRBM simulator target. That's not a trajectory it would fly operationally.
 

sferrin

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TomS said:
sferrin said:
Orbital gives it at closer to 200 miles though it doesn't state the launch conditions. With over triple the launch speed and nearly double the altitude in a ballistic flight path? 500 doesn't sound impossible.

http://www.xmission.com/~sferrin/SRAM.pdf
That range is from a lofted trajectory as a SRBM simulator target. That's not a trajectory it would fly operationally.
There were many trajectories that could be used operationally. Come to think of it though, the Orbital target wouldn't require the weight of a warhead (though I'd think they'd have to do something in the ballast dept there).

Even has a Facebook page.

https://www.facebook.com/pages/We-worked-on-the-Short-Range-Attack-Missile-AGM-69A/113202982074682
 

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I've been researching and writing about the B-70 since 1976 and I've never seen this photo before - must be for RCS testing. I'd sure love to have that model! -SP
 

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Orionblamblam

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Steve Pace said:
I've been researching and writing about the B-70 since 1976 and I've never seen this photo before - must be for RCS testing. I'd sure love to have that model! -SP
Looks like a big display model, rather than an RCS model. Note that the wing leading edges are not representative of the actual B-70.
 

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Orionblamblam said:
Steve Pace said:
I've been researching and writing about the B-70 since 1976 and I've never seen this photo before - must be for RCS testing. I'd sure love to have that model! -SP
Looks like a big display model, rather than an RCS model. Note that the wing leading edges are not representative of the actual B-70.
YES - early config - before VG wings. SAC band too - so before it was cancelled.
 

sferrin

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Abraham Gubler said:
TomS said:
Rich is sometimes full of it. SRAM had a range of around 100 miles from high altitude and a subsonic launch. Five times the range just because of a Mach 3 launch? No way.

Its from a slide on the use of an SR-71 as a strike asset. The SRAM is launched from much higher altitude and velocity than from anything else. It would make that range. I'm sure the slides in question are on this forum somewhere and on my hard drive somewhere. But I'm not looking for it, at the moment...
Here it is:

 

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It looks like the 541 nm downrange mentioned in this slide includes the distance that the launch aircraft travels between the first missile and the fourth. But I'll grant that the range is much more than I expected.
 

sferrin

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TomS said:
It looks like the 541 nm downrange mentioned in this slide includes the distance that the launch aircraft travels between the first missile and the fourth. But I'll grant that the range is much more than I expected.
That doesn't really make sense. How can it be "down range" if it's still on the aircraft? IMO the 514nm "down range" is just that; "down range" from the aircraft. What you're suggesting is something like (for example) "the SDB has 60nm down range capability when dropped from an F-22 at speed and altitude" and then in the small print saying that the F-22 carried it for 55 of those 60.
 

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sferrin said:
Abraham Gubler said:
TomS said:
Rich is sometimes full of it. SRAM had a range of around 100 miles from high altitude and a subsonic launch. Five times the range just because of a Mach 3 launch? No way.

Its from a slide on the use of an SR-71 as a strike asset. The SRAM is launched from much higher altitude and velocity than from anything else. It would make that range. I'm sure the slides in question are on this forum somewhere and on my hard drive somewhere. But I'm not looking for it, at the moment...
Here it is:

How did SR-71 (Bx) with SRAMs get into XB70 thread? -SP
 

bobbymike

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Steve

Someone hypothesized the B-70 at M3 and 70k ft. could extend the range of a SRAM to 500mi
Another poster said "I don't think so"
Someone else said, "I think I saw a graphic where the SR-71 showed a 500mi SRAM launch range"

Voila SR-71 in the B-70 thread. :D
 

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bobbymike said:
Voila SR-71 in the B-70 thread. :D
Not completely unrelated as they once were known as RS-70 and RS-71 in the Reconnaissance Strike mission.
 

LowObservable

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The low ranges on the chart are interesting. What is launching at Mach 1.6 and why is the range under 100 nm?
 

sferrin

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LowObservable said:
The low ranges on the chart are interesting. What is launching at Mach 1.6 and why is the range under 100 nm?
IIRC the SRAM could also be flown in a terrain-following profile. If an FB-111 or B-1A launched one at Mach 1.6 at medium altitude and the missile immediately dove down to low altitude flight that could account for it.

http://user.xmission.com/~sferrin/SRAM.pdf

I read somewhere back in the day that when launched from a terrain-following aircraft, and flying a low altitude profile, it's range was only something like 37 miles.
 

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sferrin said:
I read somewhere back in the day that when launched from a terrain-following aircraft, and flying a low altitude profile, it's range was only something like 37 miles.
This would not surprise me. Flying a low altitude terrain following trajectory, a vehicle would essentially remain in the air only so long as the propulsion system was running. And a rocket propelled vehicle is only going to have a very short duration of burn. As soon as the rocket burns out, the vehicle starts falling out of the sky; if it's only 100 feet up... the drop is pretty short. But if the vehicle is at high altitude, it could glide for a considerable distance, or perhaps even be lobbed into a high altitude ballistic arc.
 

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sferrin said:
That doesn't really make sense. How can it be "down range" if it's still on the aircraft? IMO the 514nm "down range" is just that; "down range" from the aircraft. What you're suggesting is something like (for example) "the SDB has 60nm down range capability when dropped from an F-22 at speed and altitude" and then in the small print saying that the F-22 carried it for 55 of those 60.

Nah, you're right. Not sure what I was thinking on that one.
 

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sferrin said:
https://www.youtube.com/watch?v=KMbOl6Hn0yQ
Thanks for posting sferrin, I have seen many XB-70 videos over the years mainly documentaries about the whole history of the XB-70 but this one is one of the best I have seen for ages.
 
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