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The XB-70 (2019)

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Re: The XB-70 (2019)

#81

Post by seabird »

jiggawatts wrote: post #80
nradov wrote: post #62

Earlier quoted context omitted.

It's always disappointing to see such uninformed and yet overconfident comments on HN. Replacing the eight small B-52 engines with four larger ones was considered and rejected years ago because it would have forced much more extensive modifications to the airframe and other systems. https://www.twz.com/6825/engine-falls-off-b-52-during-a-trai... And it's extremely difficult to convert civilian airliners into bombers.…

You're saying that my argument that "8 engines is not simple" is invalid because... it would not be simple to replace them with modern efficient engines... because there are 8 of them. Yes. We agree: the setup is not standard, not simple, and requires 2x the maintenance that 1/2 the engines would for decades and decades. Older and established isn't necessarily "simpler" or "cheaper". The average annual maintenance co…

You are comically off-base on this, man.

We are talking about a nuclear bomber. They put fucking nukes on these things. We have 70 years of operational history showing that the 8 engine arrangement works, and there is no good reason to make anything more than the most minimal changes. Go ahead and do that until you're blue in the face with some inconsequential junk SaaS product or phone app or whatever, but warplanes (and especially this one) are not the place to do it.

I'm just going to hope you're not actually serious about converting a commercial airliner to a bomber.

Re: The XB-70 (2019)

#82

Post by FpUser »

runjake wrote: post #71
FpUser wrote: post #67

Earlier quoted context omitted.

>"If the US is going to maintain a credible deterrent against China then something has to change. Either defense spending has to go up or we have to drastically scale back activities in other areas. And no, cheap AI drone swarms won't replace the capabilities of something like a B-21." Assuming the US would actually need B21 capability in a war with China. Those will be probably blown up from the sky very fast. Besid…

I think any war with China would be predominantly economic and cyber. I don’t think it’s viable for either party to perform a mainland strikes and I don’t think it would become nuclear, but who knows. If things escalate during the current POTUS’s term, I think it will come down to meetings and deal-makings, because that is POTUS’s passion and preferred way. I think any war with Russia would be, well is, economic and…

>"I think it will come down to meetings and deal-makings, because that is POTUS’s passion and preferred way."

Don't you think it looks more attractive than going up in flames?

Re: The XB-70 (2019)

#83

Post by mandevil »

Syonyk wrote: post #36
nocoiner wrote: post #33

Earlier quoted context omitted.

Was the XB-70 capable of inflight refueling? On a quick look, I can’t tell if that was the plan, or if it was going to be a one-way trip (optimistically landing in Turkey or something to refuel, but realistically…).

I don't believe it was capable of it, which is why it was so massive. The SR-71, which required inflight refueling repeatedly, only held 80k pounds of fuel (about 12k gallons). I don't have any good sense of fuel burn vs speed either, but in general, jets like to run high and fast. The old Lear 23s burned about as much fuel (pounds per hour) idling on the ground as they did at cruise, and I think the SR-71 (which mos…

The actually built XB-70's- the two prototypes- did not have a refueling receptacle. Production models would have had a boom receptacle just like the B-47, B-52 and B-58 did. It would have gone in the upper fuselage about where the delta wing starts.

Re: The XB-70 (2019)

#84

Post by mandevil »

What ended the XB-70 was SAM's, not ICBM's so much. It was much easier for the Soviets to build and deploy the SA-5 Gammon (aka the S-200 Angara, basically a perfect a B-70 killer) than it would be to build and operate a significant fleet of B-70's.

This was actually so clear to the USAF that about five years after the B-70 was canceled (about the time the first XB-70 took flight), when the Soviets actually started to deploy thousands of SA-5 across the Soviet Union, the USAF was convinced it must have ABM capabilities. It wouldn't make sense for the Soviets to use ~10% of their annual concrete production to defend against a threat that the US had already canceled, so they thought that the SA-5 had to be a super-useful national ABM capability (they had already evaluated that the ABM-1 system under construction around Moscow, the so called Triad system, as overmatched by the existing Minuteman I deployments, but thousands of missiles required more even more thousands of warheads to exhaust). In response, the USAF suddenly expressed significant interest in MIRV technology, and the Minuteman III program began, and ICBM warhead numbers started to get really insane.

Cite: https://www.thespacereview.com/article/3677/1

Re: The XB-70 (2019)

#85

Post by BonoboIO »

mrguyorama wrote: post #61
aerostable_slug wrote: post #55

Earlier quoted context omitted.

There was thought given to using 747s as cruise missile carrier aircraft. Each 747 CMCA would have carried dozens of AGM-86 nuclear-armed cruise missiles on rotary launchers that shuffled around the plane's cargo bay on rails (the missiles would be ejected one at a time from a small door near the rear of the fuselage).

Which was an interesting idea, but it eventually evolved into a much much better one: https://en.wikipedia.org/wiki/Rapid_Dragon_(missile_system)

I read something about those systems, they really have that already in service? Damn.

Those kind of system would be really „cheap“ to deploy, you overwhelm a lot of air defense systems with it and well it’s transportable outside of air defense range.

Re: The XB-70 (2019)

#86

Post by BonoboIO »

ellisd wrote: post #50

The ejection capsule design for the XB-70 is some next level engineering. Your seat would move backward into a capsule before ejection to survive the cruising altitudes of 70k feet / Mach 3. https://www.generalstaff.org/CDA/Air/B-70/XB-70_Escape_Syste...

That is a really good explanation and reference. I like those old documents.

Re: The XB-70 (2019)

#87

Post by jiggawatts »

seabird wrote: post #81
jiggawatts wrote: post #80

Earlier quoted context omitted.

You're saying that my argument that "8 engines is not simple" is invalid because... it would not be simple to replace them with modern efficient engines... because there are 8 of them. Yes. We agree: the setup is not standard, not simple, and requires 2x the maintenance that 1/2 the engines would for decades and decades. Older and established isn't necessarily "simpler" or "cheaper". The average annual maintenance co…

You are comically off-base on this, man. We are talking about a nuclear bomber. They put fucking nukes on these things. We have 70 years of operational history showing that the 8 engine arrangement works, and there is no good reason to make anything more than the most minimal changes. Go ahead and do that until you're blue in the face with some inconsequential junk SaaS product or phone app or whatever, but warplanes…

The bomber isn’t nuclear.

The payload is.

The good reason to make changes is the hard reality that your opponents won’t slow down to accomodate your old, inefficient, maintenance-heavy fleet of bombers.

Even during peacetime the B-52 fleet is burning money, money that DOGE assures the voting public cannot be wasted on frivolous matters such as HIV prevention.

It’s like the Ukraine war. Perfectly good tanks turned out to be useless sitting ducks in the face of $500 drones.

Why change anything?

Because the enemy did.

Because the rest of the world did.

Re: The XB-70 (2019)

#88

Post by ethbr1 »

psunavy03 wrote: post #64
loloquwowndueo wrote: post #29

Earlier quoted context omitted.

What killed the xb-70 was the advent of better air to air missiles that nullified its high-altitude high-speed flight advantage. ICBMs also render other kinds of bombers obsolete and yet b52 and tu-95 are still around.

> ICBMs also render other kinds of bombers obsolete and yet b52 and tu-95 are still around. This has been proven utterly false since the 1960s, because a) you can't recall an ICBM after firing it, b) you can't retarget an ICBM after firing it, and c) there's no reliable way to tell nuke warheads from conventional ones, meaning every one you launch has to be assumed to have a nuclear payload, with all the world-ending…

We also live in a world where Russia launches conventionally armed IRBMs against their neighbor.

https://en.m.wikipedia.org/wiki/Oreshnik_(missile)#First_ope...

Re: The XB-70 (2019)

#89

Post by nradov »

jiggawatts wrote: post #87
seabird wrote: post #81

Earlier quoted context omitted.

You are comically off-base on this, man. We are talking about a nuclear bomber. They put fucking nukes on these things. We have 70 years of operational history showing that the 8 engine arrangement works, and there is no good reason to make anything more than the most minimal changes. Go ahead and do that until you're blue in the face with some inconsequential junk SaaS product or phone app or whatever, but warplanes…

The bomber isn’t nuclear. The payload is. The good reason to make changes is the hard reality that your opponents won’t slow down to accomodate your old, inefficient, maintenance-heavy fleet of bombers. Even during peacetime the B-52 fleet is burning money, money that DOGE assures the voting public cannot be wasted on frivolous matters such as HIV prevention. It’s like the Ukraine war. Perfectly good tanks turned out…

Wow, you're really doubling down on the aggressive ignorance. Do you have any clue about what's involved in certifying a platform for the nuclear strike mission?

Re: The XB-70 (2019)

#90

Post by jiggawatts »

nradov wrote: post #89
jiggawatts wrote: post #87

Earlier quoted context omitted.

The bomber isn’t nuclear. The payload is. The good reason to make changes is the hard reality that your opponents won’t slow down to accomodate your old, inefficient, maintenance-heavy fleet of bombers. Even during peacetime the B-52 fleet is burning money, money that DOGE assures the voting public cannot be wasted on frivolous matters such as HIV prevention. It’s like the Ukraine war. Perfectly good tanks turned out…

Wow, you're really doubling down on the aggressive ignorance. Do you have any clue about what's involved in certifying a platform for the nuclear strike mission?

Making such a plane, yes, I have a pretty decent clue. It's not that hard. It was done with early 1950s technology!

Certifying, sadly... also yes. I work in government.

Do you think the enemy cares whether you're properly certified or not?

Similarly, do you think hackers care if your CISO has all of your security audit paperwork nicely rubber stamped?

Do viruses care if your unpatched servers have been officially exempt from the update schedule?

In war, only capability matters. Nothing else.

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