Lockheed Martin RQ-170 Sentinel UAV

[Empire]

Could this be the UAV U-2 pilots we are seeing in Iraq??

Mystery UAV operating in Afghanistan
April 10, 2009

Afghanistan maybe the testing ground for a new, advanced but as yet undisclosed UCAV programme.

Pictures shown exclusively to Unmanned Vehicles magazine and taken at an airbase in the war-torn country reveal a large flying wing-type design, adopted by UCAV designers, but not yet seen on an operational type.

The image shown in the link below has been drawn directly from the photograph but none of the experts consulted by UV had any concrete idea of what the system might be.

The image shown to UV was taken from a long distance, as the aircraft taxied in on a hazy day, but the image was clear enough to show that this UAV’s design is like no other UAV in current operational service.

Amongst the distinctive features of the type is the ‘fat’ wing chord, and a large central fuselage fairing. The aircraft engine nozzle is the same half moon shape as the Lockheed P175 Pole Cat, but the wing is not cranked on its trailing edge like the Pole Cat is.

The fuselage fairing could support a large squared off intake, but is more likely to house a large satellite communications and sensor mix. Two large blisters either side of the central fairing are likely to the intakes for a single turbofan engine. These features probably won’t help the aircraft’s radar cross-section, although this probably isn’t important considering the theatre of operations in which it is flying.

The large doors inboard of the main landing gear may be bomb bay doors, indicating a strike capability for the type.

There are clearly the technological capabilities to build something like this inside Northrop Grumman, Boeing or Lockheed Martin. Looking at the shaping, our analyst said he would be inclined to think this comes from either Northrop or Lockheed.

The shaping is also suggestive of UCAV concepts around the start of the 2000s.There is a whole raft of wing design work that has gone on since 2002 in terms of how the X-47B has evolved, and the sorts of designs that Boeing was working with prior to the ending of that effort.

[AeroFranz]

Extremely interesting.

But why send a stealthy, obviously secret, UAV to Afghanistan? What's there to gain? you can do all the testing in the world at a secret range, without blowing your cover. And given the non-existent threat level in that area, it's not like a stealthy UAV is the only asset that can provide ISR.

so once again, why send a secret UAV there?
Me, i hope it is true, but I'm skeptical.
By the way, I know it's a totally different planform, but from far this thing might look a lot like Corax. Just a thought.

[Empire]

I'm thinking they use it to fly secretly into Pakistan looking for Al-Qaida leadership targets. Could be used in all those air-strikes in the Pakistan tribal areas we keep hearing about?

[quellish]

Extremely interesting.

But why send a stealthy, obviously secret, UAV to Afghanistan? What's there to gain? you can do all the testing in the world at a secret range, without blowing your cover. And given the non-existent threat level in that area, it's not like a stealthy UAV is the only asset that can provide ISR.

so once again, why send a secret UAV there?
Me, i hope it is true, but I'm skeptical.
By the way, I know it's a totally different planform, but from far this thing might look a lot like Corax. Just a thought.

Also looks more than a little like Polecat.
<a href="http://www.youtube.com/v/Y2c9V71BRn8&rel=1" target="_blank">http://www.youtube.com/v/Y2c9V71BRn8&rel=1</a>
Or W570, or any number of other things!

If it was in use in Afghanistan, it would be because a capability or payload justifies it. Maybe they need a stealthy strike UAV in Pakistan, or maybe it carries a sensor that's particularly useful there.
There are other facilities where it could be kept away from prying eyes though, the location strikes me as strange.

[flateric]

Looks damn like W570

[donnage99]

Extremely interesting.

But why send a stealthy, obviously secret, UAV to Afghanistan? What's there to gain? you can do all the testing in the world at a secret range, without blowing your cover. And given the non-existent threat level in that area, it's not like a stealthy UAV is the only asset that can provide ISR.

so once again, why send a secret UAV there?
Me, i hope it is true, but I'm skeptical.
By the way, I know it's a totally different planform, but from far this thing might look a lot like Corax. Just a thought.

It's not necessary stealthy as in VLO like the darkstar.  A flying wing has lots of benefit in flying efficiency, especially if they are going for a long endurance uav, and of course, lowering RCS (desired whenever possible even when it's not designed to be stealthy).

[AeroFranz]

Well, I am warming up to the idea that there could be a flying wing UAV snooping around in that region. Just a few days ago. on another thread, we were talking about how General Atomics has been flying their supposedly stealthy Predator C, which "they" say is a flying wing.

But, having spent quite a bit of time on the topic (my bosses commisioned a comparative study), my two cents on flying wings achieving L/Ds in excess of tailed configurations is that in practice that does not happen. The spanwise lift distribution is not as good as that of a conventional aircraft (for stability and control reasons). The wetted area is usually greater, because you need a bigger wing on takeoff (can't trim high CL's), so higher friction drag. This, added to the fact that if you carry a satcom dish and sensors which need to protrude from the bare wing mold line, combine to make the parasitic drag of a flying wing closer to that of a tailed aircraft. IMHO, this is why you see a lot of flying wings at the conceptual stage, fewer at the prototype stage, and fewer still at the operational stage. On paper, flying wings look great, but in practice you can probably get the same performance of a tailed configuration, but you have to work twice as hard to get it by tweaking the wing parameters.
Unless you have an overriding LO requirement, like B-2 or Polecat, a flying wing is not worth the trouble.

Sorry, it didn't sound like I was on an anti-flying wing crusade! 

[avatar]

Interesting Aerofranz. I am going  way off topic ,  but I am posting this question anyway.

Given what you posted , do you think the Horten brothers were keen on the FW for the LO aspect then?

[donnage99]

Well, I am warming up to the idea that there could be a flying wing UAV snooping around in that region. Just a few days ago. on another thread, we were talking about how General Atomics has been flying their supposedly stealthy Predator C, which "they" say is a flying wing.

But, having spent quite a bit of time on the topic (my bosses commisioned a comparative study), my two cents on flying wings achieving L/Ds in excess of tailed configurations is that in practice that does not happen. The spanwise lift distribution is not as good as that of a conventional aircraft (for stability and control reasons). The wetted area is usually greater, because you need a bigger wing on takeoff (can't trim high CL's), so higher friction drag. This, added to the fact that if you carry a satcom dish and sensors which need to protrude from the bare wing mold line, combine to make the parasitic drag of a flying wing closer to that of a tailed aircraft. IMHO, this is why you see a lot of flying wings at the conceptual stage, fewer at the prototype stage, and fewer still at the operational stage. On paper, flying wings look great, but in practice you can probably get the same performance of a tailed configuration, but you have to work twice as hard to get it by tweaking the wing parameters.
Unless you have an overriding LO requirement, like B-2 or Polecat, a flying wing is not worth the trouble.

Sorry, it didn't sound like I was on an anti-flying wing crusade! 

Interesting, but then I wonder why Boeing going so far with their blended wing body?

[Matej]

Probably because of the much bigger internal space.

Given what you posted , do you think the Horten brothers were keen on the FW for the LO aspect then?

I think that it was not a primary reason - considering the fact that they started experiments with FW before any real radar was put into operational service. But the fact is also that they realized the potential of the FW for lower observability. Some of the Horten/Gotha Go-229 production models should have the fuselage made with wooden sandwich with the granular charcoal in between.

-end of off topic-

[AeroFranz]

Interesting, but then I wonder why Boeing going so far with their blended wing body?

Moderators, sorry about digressing. I promise we'll get back on track!
As for Blended wing bodies (BWB), their survival is due entirely to the persistence of Bob Liebeck at Boeing. The guy invented the BWB (also Mark Page), has been around forever (first at McDD) and has a certain clout. Plus everybody is looking for the next airliner layout to bring a leap in efficiency. I am not sure the BWB is it, though. In some aircraft design circles it has been called "the airplane without a mission" because if you look at the details of how in practice you would build and operate a BWB, in most of the missions envisaged the advantages disappear. I'm sure that there must be a thread on SPF on this, but I think some of the accepted cons are:

- A non-cylindrical fuselage is a hard structural problem in view of the pressurization requirements, so you would carry a weight penalty
- The internal passenger seat layout is pretty weird...you have "rows" of twenty seats, only a tenth of the passengers get windows, and they are not in the usual position. Overall you would be better off with LCD screens instead of windows.
- A standing human figure needs a certain height to move in an aisle. On "tube" airliners that's easy to do, and it does not affect the design of the wing. On a BWB, anywhere you put passengers, the wing thickness must be at least that tall (probabaly 1.5 times that). So if at some outboard station, say mid-span, you are carrying passengers, the wing has to be at least 1.8 meters tall (probably more, but I'm short!). For a transonic airfoil, assuming a thickness to chord ratio of say, 12, that equates to a wing chord  of 1.8x1.5x12 = 32.4 meters.
Now add a bunch of rows and the length required grows by some 36 inches per seat. That's a whole lot of wing and wetted area to fly with.
What this implies, is that BWBs work best at large sizes, where the human height requirements are proportionally smaller. I read somewhere that unless you are doing a double-decker, it makes no sense to do a BWB.
- all the previous comments on FW are still valid on BWB

So, returning to the comment of BWB is "an airplane without a mission", I think they could find niche applications, like giant transports, or maybe tankers/AEW platforms.

Sorry, now I'll get off my soap box

   

[LowObservable]

I would also mention the NorthGrum "cranked kite" as the latest shot at getting the theoretical benefits of a flying wing without some of the problems. Again, though, it underlines the fact that most successful flying wings are LO designs.

As for LO in Afghanistan - its value depends on the ethnic, political and religious leanings of Pakistani radar operators...

[sferrin]

Could be they want to operate out of Iraq but observe in Afghanistan. 

[avatar]

there are areas further afield of afghanistan ( apart from Pakistan) that require observing ...

[sferrin]

there are areas further afield of afghanistan ( apart from Pakistan) that require observing ...

Well, if you take a picture or two on your way TO Afghanistan I'm sure there's no harm.