HotshotThere are several ways that the F-35 can passively (no radar or EOTS) determine the range (and thereby velocity and vector) to an EODAS track.
1. EODAS tracks do not happen in a vacuum. By the time a track is in WVR range, the type is know. Once known, the EODAS can use the threat library to determine range and velocity based on image recognition. While this is not perfect, it’s enough to guide a WVR weapon.
2. In a vast majority of missions, there will be more than one F-35. Because of this and the automated sharing of data, two or more EODAS tracks will be compared and used to triangulate a more precise target track.
If the attacker comes from behind it is problematic because he is outside of the EOTS FOV. And if the F-35s fly far apart in bad weather their DAS could not both see the target, so they can’t triangulate. What’s the weather like in China and Russia I don’t think they are so good. Triangulating requires 2 planes so you have to approach 2 planes, which would be risky because the DAS wouldn’t have a long range, at this range the F-35s are likely to be detected in IR and radar.
Hotshotyes, if target get out of fov at intercept point there is no missile agile enough to rectify
I believe a missile like a 9X has enough burn time to make a u-turn after launch. Isn’t its burn time like 5 seconds? For sure it wouldn’t have much range after the u-turn, but for WVR it could be enough.
If the 2 planes are not crossing each other but if the bogey flies in the direction of the plane from behind, the missile would have an easier time intercepting it because the bogey would be flying towards the missile.
HotshotHotshotI had already seen that video, I wait for the real tests to see it works… The F-35 doesn’t even carry the AIM-9X internally so the point is kind of moot. The AMRAAM will have a much larger turn radius.
This being said, for a2g maybe it would work better. If the F-35 has a database with the elevation of the terrain, it can know exactly where a ground launcher ( or AAA ) would be when it fires by using its DAS. It could even have an automatic defense mode that would immediately launch an a2g missile with a terminal seeker. In that case the missile could be loaded with relatively accurate coordinates.
HotshotFrom what I understand the adaptive engine will need a lot of airflow to optimize its subsonic regime. That means a large intake so more drag. I would guess the effect would be worse in transsonic/supersonic. But the engine produces more thrust at high speed so it is likely to more than compensate.
My 2 cents…
HotshotYou mean if the 2 planes cross each other?
HotshotYou don’t seem to be able to grasp what I say so forget it…
HotshotBoth the LOAL & DAS have been tested. And even in a very primitive form where it provides no mid-course updates to missile and does not track surrounding aircraft, the DAS is still far better than any HMS by virtue conferring 360 deg visibility to the pilot even in inclement weather.
The missile in flight will not see from the same point of view as the DAS which is on the plane. Will the DAS be able to tell the missile exactly where to look from his point of view, that’s the question.
It might work, we’ll see when they test it. One thing’s for sure, a LOBL launch works very reliably, and the plane could pull a hard turn a get a shot quickly with the help of the DAS/HMD.
HotshotThe EOTS tracks all targets in the frontal hemisphere a lot more effectively than the best missile seeker. And any pilot turning hard, where enemy aircraft can emerge at any aspect, will not want the limitation of cockpit visibility or missile FoV. (BTW not all missiles can scan 90 deg off-boresight. Eg – MICA-IR.)
I am not criticising the EOTS here. The fact that it has a wide FOV is good indeed ( even though it is not a pure air to air IRST ).
I never said that the missile’s seeker should scan the entire FOV. I say that the DAS will tell the pilot in which direction the threat is coming from, and the missile’s seeker will be cued to the DAS while it is on the rail. This way the pilot can either immediately shoot if the threat is in the forward hemisphere, or make a quick turn to expose the missile’s seeker. It would happen very quickly because the missile’s seeker is already cued to the DAS. At least in that case you’re sure that the missile will achieve lock on, because there is no distance/velocity issue. It is in LOAL mode that it gets awkward, because of course the DAS and the missile are not looking from the same spot.
There’s a reason they put a two-way datalink on the Aim-9X Blk2. LOBL or LOAL, makes no difference to its pk. If the target is behind the F-35, he doesn’t need to pull a high alpha turn, he can launch irrespective of aspect or speed, and the missile will be guided both by the DAS and by its HOBS seeker, meshing together for a high pk.
The LOAL is a good capability to extend the effective range of the missile or to get off boresight shots with reliable targetting informations, which is not the case with a DAS like system.
The DAS is an IRST. By definition. And while its not equipped with an optical zoom function, that has no bearing on its native resolution.
How can this have no bearing on resolution lol? The sensor scans 120 degrees, which is a a huge volume, how can you expect to get a decent resolution with that? Originally the system was a missile launch detector, it is NOT an IRST.
– The last aircraft designed as a ‘pure fighter’ was decades ago.
– It’ll match the Eurocanards at FRP which is cheap enough for most operators.
– Half assed solution is what any F-35 pilot will call an HMS dependent dogfighter. Line up your aircraft with your target or you’re sunk. (And then hope and pray the missile does the job without help.)
Most air forces will use the F-35 as their primary fighter, and the USAF will in the end have a limited number of F-22s. Not making sure ( with enough missile tests ) that it would be a competent dogfighter with very good off boresight capability was a bad idea.
Sounds like you didn’t wait for ‘time’ before making up your mind.
Neither did you, given the fact that this DAS/LOAL capability has never been tested before.
HotshotNo its not. The missile seeker can scan only the frontal hemisphere, a large portion of which will be masked by the airframe. In addition, the pilot will be limited by what he can see from his cockpit. BTW at WVR ranges, locking on before launch would not significantly increase the pk compared to a lock achieved after launch.
Of course the missile can only lock on the target in the forward hemisphere, but if it does so, its probability of kill is quite high. With a DAS guided shot, it is not sure that it will acquire the target within one second after launch during a hard pull, when it doesn’t even know where the target is exactly.
The DAS/HMD would have been nice to have capabilities even with the ability to lock on before launch. It would have warned the pilot from incoming threat at a significant distance ( say 15km ), and the threat would have been displayed directly on the helmet, so the pilot would have known immediately where to look and where to turn quickly.
If it turns out that the target is behind the F-35, the pilot could have done a high alpha turn to get a quick HOBS shot. The whole sequence of detection, maneuvering, locking the missile would have been very quick and effective.
The DAS could eventually have been used to get a shot in LOAL mode, but with a lower pk, so probably it wouldn’t have been the preferred option.
The DAS’s actual performance with its ‘poor resolution’ (according to whom?) will be known to those who need to know. According to NG, it has the capability to ID other aircraft around it, which would make determining speed/range relatively easy. A more relevant question is how does your HMS cue a target that’s out of the cockpit’s viewing zone, or out of the missile seeker’s scan zone, how does it calculate distance/airspeed/bearing and how does it update the missile in flight?
The DAS is not an an IRST, it doesn’t have the ability to focus on a target. So its resolution will obviously be poor. To have an accurate speed, you need very accurate position data to be able to calculate the velocity vector. You won’t get that with that kind of sensor.
The JSF was not designed as a pure fighter, and was meant to be cheap. So they skipped the side bays and found this half-ass solution with a distributed aperture system.
Time will tell if it really works.
HotshotFor air to ground this is already the case:
http://www.naval-technology.com/projects/agm-88e-advanced-anti-radiation-guided-missile-aargm/
It is a pretty cool missile, but it is certainly not hypersonic. It is quoted as having a speed “over Mach 2.” Pretty quick when you consider that it has a 150lb (66kg) warhead, but a long way from hypersonic.
The AARGM-ER with a ramjet will have twice the speed and twice the range. That will make it an almost hypersonic weapon at a much lower cost. The MMW radar can probably be used to identify any target. The warhead is substantial. Very interesting weapon indeed.
HotshotThe DAS is supposed to track all enemies around it – bearing, air speed, altitude etc, use that data to optimize a missile shot for max pk, and employ the datalink post-launch to refine the trajectory with in-flight updates.
Even in the worst possible case, it cannot be worse than an HMS which just points the missile in the general direction of the target and expects missile’s seeker to do the rest. That’s hardly a problem for the DAS. And unlike the HMS it’s not limited by cockpit visibility.
With an HMS shot the missile is locked before launch. The missile’s seeker looks straight at the target so has a much better resolution of it than a wide field camera like the DAS would.
How can the DAS have the distance with its poor resolution, except for a very vague estimate? How can it have the airspeed of the target given that it doesn’t know the distance, so the variation of the distance in the first place. To be able to do that, the F-35 would have to combine the DAS with the EOTS which probably has a telemetry capability, or at least a much better resolution of the target. Would using the EOTS work in a dogfight when he planes are moving fast relative to one another? That get very complicated.
The proof’s in the pudding.
HotshotAnd that is why you mount hardware on aircraft and go test your assumptions, and why you continue to mature your models/simulations and then actually go out and evaluate the thing when it is in the air as a project. There is quite a lot of thought applied in between a system that is developed by one company and how that gets factored into the CONOPS and eventually mounted on a tactical platform, and ultimately declared operational. This obviously doesn’t mean that it cannot be a tactically wrong decision however all I am saying is that if one has issues with their assumptions, it isn’t unreasonable to assume that those questions would have also been raised by evaluators for whom the studies, and technologies were commissioned. Its not like the forum members here, or reporters in the media are figuring out stuff and questions that are unlikely to have been posed to the folks working these issues out. Every program has a level of transparency and a level of classified capability. The F-35 is no different. Getting back to the transonic acceleration timing of 55 seconds to mach 1.16 from .8, that is something that has been claimed by a person who has received both classified and unclassified briefings on the program and who has a representative at the JPO and is a partner developer. Now we know the payload, and fuel state and also the altitude. Its tough to challenge this figure while claiming inferior performance vs its peers without providing the performance data for those platforms in a similar state (payload, altitude and fuel for range). I am not saying that there is no chance that some 4th or 4.5 generation aircraft may be able to get there faster than 55 seconds, but that any advantage be it 1% or 10% has to be factored in with the overall capability here. First of all you would have to compute that advantage in the first place, and so far I haven’t seen any analysis even one with reasonable assumptions as to what that comparison looks like, yet people have no trouble calling the .04 difference and the overall LPP of 55 seconds as grossly inferior to other advanced multi-role fighters in its class.
I am not sure that Lockheed, the JPO or the USAF/N/MC and partners are much concerned about that ;).
Well, they should be concerned about seeing before believing. You can’t take for granted that revolutionary systems will work.
They have trouble apparently with flare discriminations with the DAS, and with vibrations in transsonic. How will that affect the pk of the missile is hard to tell for now. We will see when they really test missile launches. And not just one or two missiles, but at least 10 in all sorts of flight configurations. You don’t want to have bad surprises when it is time to go to war…
HotshotThe F-35s can get closer so would obtain better accuracy of the radar’s location. Possibly if they are all interconnected, even the regular superhornets could launch AARGMs if they get their target coordinates from the F-35s/Growlers. I believe the Navy has talked about the fact that the shooters would not necessarily be the lookers in their new networked architecture. For instance the F-35 will be able to guide SM-6s for over the horizon engagements.
HotshotThe USN will be operating its growlers for the next 30 years, so it certainly makes sense to invest to arm it properly early in its service life. They will surely find ways to operate the 2 aircraft synergistically. Like the F-35 can be used in stealth mode to get close to the enemy radar do have a better geolocalisation.
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