Could the XB-70 Valkyrie be feasible today?

[Scott Cunningham]

Supersonic delivery is entirely overrated. Speed is far less important than range, payload, and a host of other factors.

[Jeff]

Originally posted by Ol Paint:

True, but I was thinking that the aircraft was probably qualified earlier in its career to drop while supersonic.  I was also guessing that the B-1A program may have investigated this aspect of delivery, although modern muntions may not have been constructed with this method in mind (I am thinking specifically of the mechanicals for the guided munitions--esp. LGBs).

 

Douglas

 

Well I think the B-1A was a Mach 2 aircraft but was being designed as a nuclear bomber so there may not be much data on it dropping conventional weapons and I don't know if they were even considering it carrying guided munitions. I wonder what the nuclear capability was above Mach 1?

[Calvinb1nav]

The B-1B is limited to releases at 562 KIAS because of door limitations. I don't think the B-1A could release above that either though there is talk of testing the doors at high altitude above Mach 1 because the static pressure is lower. Or at least that's what I've heard butI'm not an aero engineer type so I'm not sure as to the specifics.

 

All B-1 combat stuff has been at high altitude and typically we go super to exit threat areas after releasing weapons. We've also done tons of supersonic low altitude stuff purely to make sonic booms during shows of force to scare the bad guys. My crew and I saved a Brit patrol in Afghanistan from a rampaging 2000-person mob by doing this. The Bone makes an incredibly loud sonic boom, much louder than other supersonic jets, and our booms showed the crowd that the patrol wasn't alone and if they didn't disperse, a JDAM might be next... If was cool to do something worthwhile without having to kill anyone and the Brits were happy they didn't have to shoot their way out too.

 

Speaking of Afghanistan, people mentioned in this thread using airliners for bombers. I'd like to the AF to buy some bomber variants of the Navy's MMA 737. Just strip out the ASW gear, keep the FLIR and radar, put some bunks for two crews for extended loiter, and hang JDAMs, Small Diameter Bombs, Viperstrikes, etc. off it... It'd be a lot better than wearing out the irreplaceable Bones and Buffs that are just droning overhead in Afghanistan now not doing much. You could also use them for crew trainers at home station...

 

PBAR

Bone WSO

[swerve]

Calvinb1nav - thanks. It's nice to have input from someone who's actually flying in the things. Much appreciated.

[Kenneth P. Katz]

As an advocate of an airliner-derived bomber, I somewhat agree, somewhat disagree. Certainly that type of airplane is not going to be radically different in capabilities than a B-52H. But I believe that the true value is in the weapons, sensors and networking, which means that even a radical a concept as a transatmospheric hypersonic bomber is not going to be radically more effective than a B-52H.

 

An airliner-derived bomber would offer the following significant advantages over a B-52H.

 

1. Greatly increased unrefueled range. An airplane with the range of a 777-200LR or A340-500 (9000+ miles) could fly a typical OEF or OIF sortie from RAF Fairford or Diego Garcia without aerial refueling. This is a huge savings, because a B-52H required two refuelings to do those missions.

2. Substantially reduced life cycle costs, due to modern systems which can leverage the commercial O&M market and are more reliable.. Also much less fuel burned.

3. Easier to deploy. Less support and maintenance personnel, less spare parts, less AGE. The B-52H doesn't have an APU so it needs a traveling circus to precede it.

 

These are not sexy advantages, but they are important ones in an era where the USAF needs a global strike force that is less dependent on basing rights that may be withdrawn by fickle allies, and may not be available at all due to Iranian missile attacks. Not only would such an airplane be a great JDAM truck, but with JASSM it would be able to attack well defended targets.

 

Bottom line: the competitive advantage comes from the weapons, sensors and network. The bombers should be long range, affordable and numerous, not sexy.

 

Originally posted by JOE BRENNAN:

For the US, big airliner based "arsenal ships" have the problem mentioned of not being superior enough to the B-52. I guess the idea of going as low down as C-130 is to avoid this competition. I still really doubt that one. And not really hot on FB-22 either.

[Smitty]

Originally posted by Calvinb1nav:

Speaking of Afghanistan, people mentioned in this thread using airliners for bombers.  I'd like to the AF to buy some bomber variants of the Navy's MMA 737.  Just strip out the ASW gear, keep the FLIR and radar, put some bunks for two crews for extended loiter, and hang JDAMs, Small Diameter Bombs, Viperstrikes, etc. off it...

 

IIRC, the MMA has a crew rest area.

 

IMHO, we should just use Navy MMAs for this purpose. They can just be rotated off patrol duties during these types of conflicts.

[Burncycle360]

As an advocate of an airliner-derived bomber, I somewhat agree, somewhat disagree. Certainly that type of airplane is not going to be radically different in capabilities than a B-52H. But I believe that the true value is in the weapons, sensors and networking, which means that even a radical a concept as a transatmospheric hypersonic bomber is not going to be radically more effective than a B-52H.

An airliner-derived bomber would offer the following significant advantages over a B-52H.

 

1. Greatly increased unrefueled range. An airplane with the range of a 777-200LR or A340-500 (9000+ miles) could fly a typical OEF or OIF sortie from RAF Fairford or Diego Garcia without aerial refueling. This is a huge savings, because a B-52H required two refuelings to do those missions.

2. Substantially reduced life cycle costs, due to modern systems which can leverage the commercial O&M market and are more reliable.. Also much less fuel burned.

3. Easier to deploy. Less support and maintenance personnel, less spare parts, less AGE. The B-52H doesn't have an APU so it needs a traveling circus to precede it.

 

Just curious, what do you mean by airline derived? Purpose built bombers based on airliners, or actual airliners converted to carry bombs?

[Kenneth P. Katz]

What I envision is a purpose-built fuselage with airliner wings, propulsion (engines, struts, nacelles) and tail. As much as possible, the systems such as APU, pneumatic, hydraulic, electrical, flight controls, cockpit displays would be COTS. I assume that is what the MMA based on the 737 is.

 

Originally posted by Burncycle360:

Just curious, what do you mean by airline derived? Purpose built bombers based on airliners, or actual airliners converted to carry bombs?

[Smitty]

Originally posted by Kenneth P. Katz:

What I envision is a purpose-built fuselage with airliner wings, propulsion (engines, struts, nacelles) and tail. As much as possible, the systems such as APU, pneumatic, hydraulic, electrical, flight controls, cockpit displays would be COTS. I assume that is what the MMA based on the 737 is.

 

 

Hmm.. Didn't appear that way to me. The MMA looks like a normal 737 with a small bomb bay cut in the rear fuselage and strengthened wings. Now, I suppose, looks can be deceiving. There's no way to tell how much it has in common with a stock 737.

[Kenneth P. Katz]

I suspect (don't know for sure) that there are enough changes to the MMA fuselage compared to an airliner that it is essentially a new structure, albeit with the same shape as an airliner fuselage. Obviously there would be many similarities and some identical parts.

 

Originally posted by Smitty:

Hmm..  Didn't appear that way to me.  The MMA looks like a normal 737 with a small bomb bay cut in the rear fuselage and strengthened wings.  Now, I suppose, looks can be deceiving.  There's no way to tell how much it has in common with a stock 737.

 

[Smitty]

Originally posted by Kenneth P. Katz:

I suspect (don't know for sure) that there are enough changes to the MMA fuselage compared to an airliner that it is essentially a new structure, albeit with the same shape as an airliner fuselage. Obviously there would be many similarities and some identical parts.

 

 

You may be right, though I wonder how much is just re-engineering certain areas (around sensor fairings, weapons & sonobouy bays, wings) and how much is clean sheet design?

 

The more they diverge from the basic 737, the harder it'll be to use the same production line facilities, without significant modification.

[Jeff]

Originally posted by swerve:

Calvinb1nav - thanks. It's nice to have input from someone who's actually flying in the things. Much appreciated.

 

Ditto

[Burncycle360]

What I envision is a purpose-built fuselage with airliner wings, propulsion (engines, struts, nacelles) and tail. As much as possible, the systems such as APU, pneumatic, hydraulic, electrical, flight controls, cockpit displays would be COTS. I assume that is what the MMA based on the 737 is.

Agreed

 

I'm not in favor of cutting holes into existing airliners and stuffing bombs in them, then calling that our future bomber fleet. But I think building the thing from the ground up as a bomber, BASED on the airliner would a good idea.

 

The more they diverge from the basic 737, the harder it'll be to use the same production line facilities, without significant modification.

 

Much if not all of the tooling already exists, most of the parts are off the shelf, and the manufacturing process is much the same.. but yes, depending on how far you diverge it may require some new tooling, but that's a drop in the bucket compared to starting from scratch, and now you have a purpose built aircraft. It may only be 90% commonality with it's airliner brothern in the end, but it's easier to develop that last 10% than it is to start from a clean sheet of paper, and I imagine doing it this way lets you incorporate features required in a military aircraft without too much improvisation as when you start taking old airframes and figureing out ways to fill them with bombs.

 

 

[Edited by Burncycle360 (08 Dec 2004).]

[Smitty]

Originally posted by Burncycle360:

I'm not in favor of cutting holes into existing airliners and stuffing bombs in them, then calling that our future bomber fleet. But I think building the thing from the ground up as a bomber, BASED on the airliner would a good idea.

 

For a mission profile that consists primarily of boring holes in the sky for long periods, in a zero high-altitude threat environment, I favor using a platform we already intend on buying in reasonably large quantities.

 

IMHO, this mission doesn't require huge payloads. The MMA, as spec'd, can probably carry 4 quad-SDB racks externally and at least a couple more internally. This should be MORE than enough for Afghanistan or Iraq nowadays. Heck, I bet they could get by with two racks internally, and not pay external carriage drag penalty.

 

For everything else, I'd rather see new designs that can handle the full range of threats.

 

 

 

[Edited by Smitty (08 Dec 2004).]

[Ol Paint]

Originally posted by Jeff:

Ditto

 

I'll "third" this comment. Thanks.

 

What I'd really like to see would be continuation of the three-bomber strategy that is currently in existence. Stealthy, general purpose strike, and long-endurance/high-altitude bombardment (my ad hoc definitions). The first role would be filled by the B-2 and a super-stealthy successor. The second would be filled by the B-1 and the Mach 2-3 successor that I have an irrational affection for. And the third leg made up of the aircraft advocated by Kenneth Katz and others--the B-52 and an airliner based new-build.

 

I could see this third aircraft marrying a purpose-built fuselage with a UAV control system and airliner landing gear, wings, engines, and empennage. If this aircraft is intended to mainly perform long-range, high-endurance, standoff strike, I don't see any benefit to including crew in the design. Instead, it just becomes another part of the weapon delivery system and need not incorporate such luxuries as cabin pressurization, windows, and crew volume.

 

For the general purpose strike role, I want an aircraft like the B-1R that is capable of operating in a moderate-threat environment with the performance and flexibility to operate in a variety of delivery profiles--low level penetration, high-level bombing, delivery of precision and dumb munitions, etc. I want a man in this aircraft due to the more intense decision-making environment and shorter reaction times. Because this is a manned aircraft, I want high performance to keep the crew's mission lengths short for improved personnel performance.

 

Finally, the high/very-high threat environments would be handled by a limited fleet of super-stealthy aircraft that should be capable of clearing a path for the other two aircraft in time of major war. The B-2 performs this role well, it would seem, and I would expect a similar aircraft to be delivered as a replacement. This, too, would be a manned system and I would prefer a supersonic version, but signatures would be an over-riding concern and may require a slower aircraft.

 

Have fun with that proposal...

 

[Edit: I forgot to add that I don't want a heavy bomber force designed around the SDB--it should be one tool among many. While it sounds like a nifty piece of ordnance, sometimes you just want to drop a 5,000lb GBU on someone. At the very least, a heavy bomber should be designed to carry a full spectrum of ordnance internally. External carriage should be limited to really large items like MOAB, if this is desired. This is one of the primary issues I have with the FB-22 proposal--it seems as if the aircraft would carry these almost exclusively. Flexibility is much more beneficial.]

 

Douglas

 

[Edited by Ol Paint (08 Dec 2004).]

[Kenneth P. Katz]

Why do you need a stealthy bomber when a non-LO airplane can carry stealthy missiles at a fraction of the cost?

 

Why do you need a supersonic bomber when an subsonic airplane can carry hypersonic missiles as a fraction of the cost?

[Chris Werb]

One thing we've seen in recent conflicts is that even a relatively old SAM system manned by cunning humans can be very survivable. For that reason I'm not sure it will be possible for a super stealthy aircraft to clear a way for non stealthy types in a timely manner. The non stealthy types will (IMHO) therefore be limited to standoff launches or to operating in benign air environments. Fortunately, that wouldn't prevent their effective use.

 

Even countries with the densest, most state of the art IADS still have an infrastructure that is inherently every bit as vulnerable to standoff weapons as that of countries that have no IADS at all. It is very hard to hide electricity generation, transportation and petroleum production/refining/distribution. Standoff weapons can deindustrialise a technologically advanced opponent in short order.

 

On the other hand, I'm not sure relocatable targets warrant the massive expense of stealth bombers - even if the latter are completely invulnerable to IADS. Back in the cold-war, hunting mobile Soviet ICBMs was seen as justification for manned stealth bombers - they would have had to find them in one mission. 1991 proved that such relocatable targets are virtually impossible to find even when you have many days, complete air supremacy, large numbers of highly capable sensors and shooters and a much smaller area of relatively simple terrain to find them in.

 

[Edited by Chris Werb (08 Dec 2004).]

[Chris Werb]

Originally posted by Kenneth P. Katz:

Why do you need a supersonic bomber when an subsonic airplane can carry hypersonic missiles as a fraction of the cost?

 

Following Ol Paint's argument, a hypersonic plane would get to the target much faster and generate a much higher sortie rate than a subsonic aircraft. Whether it would deliver more weapons per day over a protracted air campaign than the same amount of money spent on near COTS technology is open to question, but it's an interesting idea all the same.

[Smitty]

Originally posted by Kenneth P. Katz:

Why do you need a stealthy bomber when a non-LO airplane can carry stealthy missiles at a fraction of the cost?

 

Well, a couple of reasons jump to mind,

 

1. Standoff missiles are expensive, JDAMs are cheap. This means more targets struck per dollar, even if the hourly operational cost is significantly higher for a stealthy bomber.

 

2. Standoff missiles are larger and heavier than bombs. Thus using bombs means, potentially, more targets hit per sortie.

 

3. A stealthy bomber can be part of your sensor network. The more eyes you have looking, the greater the chance of finding something.

 

 

 

 

[Edited by Smitty (08 Dec 2004).]

[JOE BRENNAN]

Stealthy aircraft, not necessarily big bombers, can do things like position themselves in locations where they can better hear or jam (and that's not necessarily contradictory with stealth, consider very narrow angle jamming with an AESA radar etc.) air defense transmissions, or say detect enemy attackers from over their territory looking at them from behind where they are less stealthy (OK getting toward a fighter mission there). Also w/ very upscale very long range air defense systems, vulnerability of targetting sensors, besides spacecraft, that would pinpoint relocatable targets for very long (few 100mile) standoff attack, becomes a question. On the same theme LO aircraft for certain other missions like MC-130, AC-130, etc, and for which you can't standoff, are interesting. So I like BMACK, as a concept to play around with lets say pending reaching the bottom line of how expensive it is (doing stuff like estimating for argument purposes from the B-2, long ago now tech, sunk costs, tiny production, is meaningless I think. I wouldn't strongly claim OTOH it's affordable, at this point).

 

A 1:1 B-2 replacement or restart of production as some had long lobbied for is hard to justify; can't argue with that.

 

Another consideration of stuff like BMACK or hypersonics v. COTS bomb truck is time horizon. You can't do everything over time just as you can't at any given time, there's a choice to emphasize state of art advancement for a longer horizon, or warfighting in the near future. As a relative, not all or nothing emphasis. I think Iraq on the one hand focuses resources on its short term requirements: it has to come first for right now. After that in a few years I think it creates a situation somewhat like post Vietnam, threats will be there but the US reluctance to go to war over them (and international opposition to it doing so) sharply higher. So the emphasis will tend to shift more long term.

 

Joe

[Smitty]

Originally posted by Chris Werb:

1991 proved that such relocatable targets are virtually impossible to find even when you have many days, complete air supremacy, large numbers of highly capable sensors and shooters and a much smaller area of relatively simple terrain to find them in.

 

<font size=1>[Edited by Chris Werb (08 Dec 2004).]

 

I think this solvable, at least partially. The problem with 1991 was, even though we had a large number of aircraft with capable sensors (by 1991 standards), we still didn't have the temporal and area density and fidelity of sensors necessary.

 

That doesn't mean there isn't a tipping point of sensor density/fidelity that won't do the job.

[Chris Werb]

If you have to send something into defended airspace to locate relocatable IADS targets, why not put those sensors in a larger number of much more expendable networked unmanned platforms? If you can use unmanned platforms to find those targets, why not use them to strike them?

[Smitty]

Originally posted by Chris Werb:

If you have to send something into defended airspace to locate relocatable IADS targets, why not put those sensors in a larger number of much more expendable networked unmanned platforms?  If you can use unmanned platforms to find those targets, why not use them to strike them?

 

IMHO, even an undefended airspace lends itself to a large number of unmanned platforms. They are cheaper to buy and operate and can stay up for much longer than manned aircraft. Now to get a high enough density, the UAVs may need to have a significant degree of automatic target recognition, so operators don't have to monitor every UAV's video feed. Instead, they can just filter out false alarms and confirm targets for attack.

 

The main problem I see with making unmanned platforms capable of striking targets is that carrying munitions adds extra weight and is only possible on larger UAVs. To get a sufficient density of UAVs, you may have to go to a small enough size to make arming them with a useful munition unfeasible.

 

Now maybe that means you go down the LOCAAS/LAM route and make the UAV a munition as well as a sensor platform. Or maybe you just arm the higher tiers of UAV and leave the lower ones as sensor-only.

[Kenneth P. Katz]

A subsonic aircraft loitering off the cost of Iran could put a hypersonic missile on a missile TEL within minutes of the TEL being detected. I ask again, why does the aircraft have to be hypersonic?

 

Originally posted by Chris Werb:

Following Ol Paint's argument, a hypersonic plane would get to the target much faster and generate a much higher sortie rate than a subsonic aircraft. Whether it would deliver more weapons per day over a protracted air campaign than the same amount of money spent on near COTS technology is open to question, but it's an interesting idea all the same.

 

[Kenneth P. Katz]

Yes, but stealth bombers are astronomically expensive. In peace time, the missiles sit packed up in boxes in munitions igloos. The bombers are expensive every day.

 

Originally posted by Smitty:

1.  Standoff missiles are expensive, JDAMs are cheap.  This means more targets struck per dollar, even if the hourly operational cost is significantly higher for a stealthy bomber.