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A Defense Technology Blog
JSF - "Maneuvering is Irrelevant"

Two weeks ago at the Air Force Association convention, Northrop Grumman briefed media on the Distributed Aperture System (DAS) that it is developing for the F-35 Joint Strike Fighter. Subsystem briefs aren't always revealing, but this was different.

As this story in DTI (p40) explains, DAS comprises six fixed, wide-angle infrared cameras that constantly image the entire sphere around the F-35. It's been publicized in the past for its ability to allow the pilot to "see through the floor" in a vertical landing, and one of its functions is to provide imagery to the VSI helmet-mounted display. Another is missile warning. But one of the DAS' most interesting capabilities is that it can constantly track every aircraft in the sky, out to its maximum range - which varies but, absent clouds, covers the within-visual-range envelope.

DAS has two vital attributes in this respect:  it stares, never looking away from any target, and it has optical accuracy, with megapixel-class resolution. (Northrop Grumman didn't say "megapixel", but one of their suppliers did. Bad supplier! The naughty spot for you!) This means that once a target is ID'd, it stays ID'd, and the pilot can see what every aircraft around him is doing.

Moreover, DAS is expected to track with enough accuracy and tenacity to permit a safe high-off-boresight, lock-on-after-launch (LOAL) missile shot with any datalink-equipped missile. Indeed, Northrop Grumman's DAS business development leader, Pete Bartos - who was part of the initial USAF JSF requirements team - says that this was basic to the F-35 design and the reason that it did not need maneuverability similar to the F-22. Rather than entering a turning fight at the merge, the F-35 barrels through and takes an over-the-shoulder defensive shot. As a Northrop Grumman video puts it, "maneuvering is irrelevant".

What this says about the F-35 is that the 1995 statement of its godfather, George Muellner, still stands:  it is 70 per cent air-to-ground and 30 per cent air to air. Consider the USAF, by far the largest customer, in 1995. It was expecting to get 442 F-22s, which would dominate any foreseen air threat (a major regional power) for decades. It was four years after Desert Storm, where the F-117 had been the star, combining stealth and precision attack into an overwhelming force multiplier.

Looking back, the USAF was clearly seeking something that would do the F-117 job while remedying its limitations. The F-117 was a clear-night system, unable to bomb in adverse weather or survive in daylight, and could not hit all the targets covered by other strike aircraft.

The JSF requirement was built around an F-117's internal weapon load. It added a radar and GPS-guided weapons for all-weather attack. It added situational awareness (that is, an EW system capable of detecting, identifying and avoiding pop-up threats) and AAMs for self-defense, for daytime survivability. Finally, it added external pylons for the "day two" missions and the entire target set tackled by F-16s.

All this had to fit inside the tightest limitation imposed by the joint-service JSF concept, which was size:  the Marines and the UK wanted (but didn't get) an aircraft no bigger than an F/A-18C.

Within those limits, the JSF could not be designed for the supersonic cruise and maneuverability that had been included in the F-22. Moreover, it was the first USAF requirement written after the end of the Cold War, and the rude shock of realizing just how dangerous the Vympel R-73 and associated helmet-mounted sight would be in close combat.

Rather than attempting to play a game that might be mutual suicide, the JSF requirement authors stressed stealth, situational awareness and LOAL. If the fight does get to the merge, the best thing to do in an F-35 is to accelerate through it, put the adversary in the rear sector and take an over-the-shoulder shot.

Of course, the use of 360-degree weapons on a fighter has an illustrious precedent...

blog post photo

...about which the less said the better. If the Germans had had an expression for "clubbed like baby seals" in 1940, the Luftwaffe would have used it.

The other first-level observation about the JSF self-defense strategy is that - at service entry - the jet won't carry (internally) a missile that is very suited to the job. The AIM-120 can in theory be vectored in any direction, although it generally receives updates via the radar, which cannot update the missile outside its field-of-regard, and the weapon's design emphasizes range and speed rather than agility. The F-35 can carry the AIM-9X Block 2 or ASRAAM, but only on external pylons. And even with a more-stealthy pylon design - discussed earlier this year - that's a serious compromise.

Eventually, the F-35 may get an internal, LOAL AIM-9X capability - because that's what it really needs to take advantage of DAS.

Tags: ar99jsfnorthropgrummandas
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viperfan wrote:
On your last sentence; DAS can not as far as I know target a weapon and acts only as a warner system for a 360 degree situational awareness in the IR spectrum. Nightly formation flying, threat detection and so on.

I'm also concerned as to how DAS (and in the extension the pilot itself) would enjoy a burst of multispectral flares from a possible opponent.
10/2/2008 3:51 PM CDT
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Obamanite wrote:
You know, Bill, I enjoy reading your articles and columns, I really do, righ up until the point where you get all sophist and demagogue on us and use an example from WWII to illustrate why current and future doctrine may not work. You do this repeatedly, and it really is quite annoying, and does a diservice to your otherwise fine work as an aviation journalist. You often make good points, when you try and remain level-headed and objective. But when you try and score points by being overly cute and clever, you completely subvert any claim to thoughfulness and objectivity. Just sayin'...

I did ask in another post you may not have seen, do you not think the RAND report on basing was a bit of a glowing endorsement for your 1980s-era crusade that all fighters should be V/STOL? And, that being the case, why would you not now be a staunch advocate of thousands of F-35Bs to supplant most if not all existing Western fighter aircraft? If submunition-laden ballistic missiles are likely that much of a current and future threat, what in god's name are we doing basing our fighter and bomber fleets on conventional runways!? I'm just sayin'...
10/2/2008 3:52 PM CDT
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Obamanite wrote:
Viperfan wrote: "DAS can not as far as I know target a weapon and acts only as a warner system for a 360 degree situational awareness in the IR spectrum. Nightly formation flying, threat detection and so on."

"Sweetman wrote: Moreover, DAS is expected to track with enough accuracy and tenacity to permit a safe high-off-boresight, lock-on-after-launch (LOAL) missile shot with any datalink-equipped missile. Indeed, Northrop Grumman's DAS business development leader, Pete Bartos - who was part of the initial USAF JSF requirements team - says that this was basic to the F-35 design and the reason that it did not need maneuverability similar to the F-22. Rather than entering a turning fight at the merge, the F-35 barrels through and takes an over-the-shoulder defensive shot. As a Northrop Grumman video puts it, 'maneuvering is irrelevant'."

Viperfan, when all else fails, try reading.
10/2/2008 3:55 PM CDT
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ELP wrote:
Here is a WWII thing that is true... the faster aircraft always gets to decide how to control the fight. After the 2 missiles are gone and the fact that big SUs have IRST, I don't think the silly DAS video showing F-35s going nose-on and blowing on through holds water. Here, the NUMBER of A2A missiles count for something and so does a gun. Which btw a B or C F-35 may have left the deck that day without their gun pod. Oh dear.
I'm happy that the F-35 has some neat stuff. I think it can kill big SUs. I think it can also be killed by big SUs. When LM/Pentagon is a little more honest on this, I'll trust them.
10/2/2008 5:07 PM CDT
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irtusk wrote:
Bill, your DTI article implies that the F-35 simply cannot do post-stall maneuvering at all, yet Code One says "The F-35 can maneuver post-stall like an F/A-18."

http://www.codeonemagazine.com/archives/2007/articles/apr_07/flighttest/index.html

ELP, can we get over the 'only 2 internal missile' thing already? We all know that it is going to have at least 4 internally.
10/2/2008 7:20 PM CDT
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irtusk wrote:
> think it can kill big SUs. I think it can also be killed by big SUs. When LM/Pentagon is a little more honest on this, I'll trust them.

have you seen any videos from the Russians showing how their big SUs can be killed by F-35s?

have you seen any videos from the EF consortium showing how the EF can be killed by the Su?

why are you holding LM to a different standard than everyone else?
10/2/2008 7:23 PM CDT
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viperfan wrote:
Obamanite, "Viperfan, when all else fails, try reading." Yes... did you?

I wrote target. Not track.

That's why a datalink is not only helpful but required as the missile will need to receive target data from the radar. And that means emitting energy.
10/2/2008 8:49 PM CDT
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Obamanite wrote:
Viperfan: An HMD alone, without the need to emit energy (as from a radar) can cue an off-boresight missile and target it. The DAS can do the same. "Moreover, DAS is expected to track with enough accuracy and tenacity to permit a safe high-off-boresight, lock-on-after-launch (LOAL) missile shot with any datalink-equipped missile." The first part of the sentence means DAS can track, the second part means that it can target.
10/2/2008 11:15 PM CDT
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ELP wrote:
Ski Rut
It Rusk
Ti Rusk

Hmmm those anagrams have to mean "Lockheed apologist" in some language.

Irtusk... The F-35 has a lot of testing to do and the marketeers are writing checks that we don't know if the engineers can cash them yet.

Keep trying though.


10/2/2008 11:28 PM CDT
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irtusk wrote:
> Hmmm those anagrams have to mean "Lockheed apologist" in some language.

funny, people were calling me an EADS apologist earlier ::rolleyes::

> the marketeers are writing checks that we don't know if the engineers can cash them yet

the engineers certainly know at this point

and if you're concerned about the marketing people just flat out lying, do you have the same concerns about the EF or Sukhoi marketing people?

all the claims about Russian radar being able to detect the F-35 beyond AMRAAM range which is quite funny considering they have no idea what it's radar signature looks like

and then there's this video, talk about writing checks we don't know if they can cash!

http://www.truveo.com/Eurofighter-Typhoon/id/3818638982

10/3/2008 1:07 AM CDT
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