IR missile protection

[TorwaK]

Bell company is working on new IR missile protection solutions. The news to quote from http://www.vtol.org/pdf/61OperationsII.pdf First picture about original AH-1W exhaust exhale effect to tail. Those pictures have taken at hover mod, 60KIAS, 120KIAS speed about IR trace.

 

 

New design AH-Z exhaust system to make less IR trace on tail. The system provieds to make hot exhaust exhale cooling by rotors.

 

 

New AH-1Z system effect on IR trace.

 

 

The same system on Apache.

 

[Yellonet]

Strange that such a design wasn't implemented from the start, or at least a long time ago.

[FOD]

I can't see how big an improvement that is if the magnitude of the IR images graduations is the same. If I was an IR missile I would still think the exhaust outlet looks like a target!

 

The apache vents directly up and probably has a lot of turbine bypass to cool the parts that are exposed to the hot gas flow. Not as many missiles will attack from above. hopefully.

[Sundowner.pl]

That Apache photo is interesting, there are ATIRCM turrets on wing tips, it looks like the Army won't incorporate the AN/ALQ-212 system in a pods like on European WAH-64s, but implement whole system into the machine.

[Yellonet]

I can't see how big an improvement that is if the magnitude of the IR images graduations is the same. If I was an IR missile I would still think the exhaust outlet looks like a target!

The IR signature seems to be significantly smaller, thus making getting a lock at distance harder.

[159th_Viper]

Would be interesting to know what effect, if any, this countermeasure would have on the SA-24 Grinch.

[Geier]

Interesting

[TorwaK]

That Apache photo is interesting, there are ATIRCM turrets on wing tips, it looks like the Army won't incorporate the AN/ALQ-212 system in a pods like on European WAH-64s, but implement whole system into the machine.

 

you're right. An example Agusta A-129 is using Lockheed Sanders AN/AQL 144. I call it like disco ball :)

 

[Sundowner.pl]

I don't refer to the 'disco ball', I'm talking about the ATIRCM/DIRCM active countermeasure turret:

 

 

There are two of those mounted on that Apache on the wingtips, similar to the European WAH-64Ds, but the Europeans mount AMASE pods there, that have both CMWS sensors and chaff/flare launchers, and soon will get those DIRCM turrets. So it appears that the Americans will keep mounting the CMWS on the chopper itself and just mount the laser turrets on the ATAS mounts.

 

Here's some info about the AMASE with DIRCM

[BBQ]

Good, informative thread :)

[TorwaK]

I don't refer to the 'disco ball', I'm talking about the ATIRCM/DIRCM active countermeasure turret:

 

Sorry me I confused with ALQ and AQL. ;)

[joey45]

when you say the Europen WAH-64D, do you mean the British WAH-64D....

[Sundowner.pl]

Rather continental Europe - Netherlands and Dutch

 

The Brits AH Mk1 have CMWS system on the airframe.

[FOD]

QUOTE Here's[/url] some info about the AMASE with DIRCM /QUOTE

 

Thanks Sundowner, that was an excellent link.

[joey45]

cos the W stands for Westland ie british

[Jascha]

New design AH-Z exhaust system to make less IR trace on tail. The system provieds to make hot exhaust exhale cooling by rotors.

 

Some photos of it:

 

 

 

 

New exhaust for AH-64 looks awesome. Anybody has some more photos of it? Hard to find...

[Sundowner.pl]

This might be the Block III evaluation chopper, Boeing is working on those for more than a year now.

[Jascha]

This might be the Block III evaluation chopper, Boeing is working on those for more than a year now.

 

Boeing or Bell?

 

Here is the article (Italian & English):

http://www.fly-net.org/aeromedia/h1exhau.html

 

It's from June 2004.

 

Have fielded versions of AH-1W in Afghanistan and Iraq been modded with HIRSS already ? Because according to this (old) article this process should have begun in March 2005. :hmm:

[Sundowner.pl]

I'm talking about AH-64Ds, the papers for work on it were signed in august, last year.

[Jascha]

:doh:

 

Ohhh. OK. Sorry. :angel:

 

Still - if someone has some info about the fielded versions of AH-1W(/Z) using turned exhaust system post it please. These pictures are also pretty rare, I guess.

[Wdigman]

Probably a dumb question, I asked this at an airshow and just got an generic answer, but what does the AN/AQL 144 and ATIRCM/DIRCM do, Becides "tell the missle not to go here". How does it work? Do they fire a laser at the IR missle head blinding it or burning out the seeker's optics. Probably not a question for this thread but we are on topic of countermeasures.

 

Also how do the IR warning sensors distinguish from a sam launch (IR) and flares or reflections from the ground.

 

Just asking.

[joey45]

it blinds the seeker head i believe...

[Sundowner.pl]

Probably a dumb question, I asked this at an airshow and just got an generic answer, but what does the AN/AQL 144 and ATIRCM/DIRCM do, Becides "tell the missle not to go here". How does it work? Do they fire a laser at the IR missle head blinding it or burning out the seeker's optics. Probably not a question for this thread but we are on topic of countermeasures.

 

Also how do the IR warning sensors distinguish from a sam launch (IR) and flares or reflections from the ground.

 

Just asking.

Ok, here ya go:

 

- AN/AQL-144, or any other 'disco ball' actually try to blind the missile seeker, making it see a target large as the sun. When its far away, they can still home on that huge heat signal, but when they coming closer, the seekers are totally blinded and can't see s...stuff ;) so they should fly by. Well in reality it doesn't always work that way, because modern sensors can work on few frequencies, they can just ignore that kind of jamming - almost all new seekers that based on IIR technology, are immune to those systems.

 

- ATIRCM/DIRCM comes to the rescue in those situations, those systems are small turrets with optics for targeting and some sort of beam projector - it may be laser, or microwave. Different manufacturers have different approaches. What those do is actually shooting a beam of energy at the missile completely blinding the missile sensor. It is a high energy beam, not enough to actually fry the sensor, but high enough to rise its temperature high enough to become completely blind.

 

- The CMWS and similar threat detection system work pretty simple, they work in IR and UV. So, what would be a flare ? A slow, falling down bright light that is across the spectrum. Reflections? They're short in time, and only in IR or UV. So now how to identify a missile ? Its visible only in IR, going fast, and with time its being more and more intense. Of course those systems are not fool proof, and they have some response time, but that's still better than Mk1 Eyeball ;)

[GGTharos]

Disco balls don't try to blind the seeker, IIRC - rather, they take advantage of how reticle seekers work, and flash pulses at an interval that will confuse the seeker (because a reticle seeker itself depends on a spinning disc that periodically occludes the target - ie. the missile sees the target in pulses)

[Wdigman]

Thanks very informative.