That IR Sensor On The Bottom of the F-4B/4C/D...

[exhausted]

What I want to know is who got to work with it (pilot or rio/wso), what it did (ranges, whether or not a 'lock' could be aquired), and what it's display looked like.

 

Does anyone have any light to shed on this mysterious device?

[+Dave]

What I want to know is who got to work with it (pilot or rio/wso), what it did (ranges, whether or not a 'lock' could be aquired), and what it's display looked like.

 

Does anyone have any light to shed on this mysterious device?

 

I asked this same question a few years ago and there is not a lot of info on it at all. I mean after all these years its still hush hush. I would very much like to know as well. I know what it does and that is about it.

[+Crusader]

AAA-4 IRST

 

RIO/WSO operated it ( it was replaced by ECM stuff pretty soon )

ranges.. several NM. depends on heat source, weather etc .. real values are all in the classified manuals which are not available

display... it looked and worked pretty much like a radar , searching with bars but with a much smaller coverage in az/el

the IRST could be switched into a tracking mode , and the radar slaved to the IRST and used to get range info with a short transmit ( took a couple seconds, iirc )

[+Crusader]

http://sistemadearmas.sites.uol.com.br/ca/irst.html

 

Run this page through a translator ( Portuguese to English ) YYAHOO! Babelfish translation

 

This picture shows the IRST of the F-8D and early F-8E

[+streakeagle]

The F-4B was the only variant to ever have the IRST. F-4Cs came with chin pods for commonality of parts to simplifiy and speed up delivery. Late model F-4Cs and early F-4Ds had no chin pod. The chin pod was brought back for F-4Cs and F-4Ds to house RWR antennas. I can't recall off hand, but I am pretty sure even the F-4Bs eventually gutted their chin pods for RWR antennas, especially by the time they were converted to F-4Ns. The lack of the IRST on the F-4J should give you an idea of how much this system was liked/used by the USN. Of course, IRST showed up on the F-14A only to be replaced by TCS. Then both IRST and TCS were installed on the F-14D.

[+Crusader]

Yes, ECM was more important on the F-4B than the IRST

 

Also, IRST is never mentioned in any of the RB events, iirc .. wasnt a factor at all.

[+MigBuster]

Nice info thanks - have seen little about them.

 

So it claims the PIRATE can detect targets at 100km - sounds like wishful thinking to me - but who knows

[+Gr.Viper]

So it claims the PIRATE can detect targets at 100km - sounds like wishful thinking to me - but who knows

It might detect a nuke going off at that range.

[exhausted]

Was the F-4/F-8's IRST device anything like that of the MiG-29 and Su-27's?

[+Gr.Viper]

Floggers and Foxbat also carried IR sensors but I can't find their stats.

[+SkippyBing]

So it claims the PIRATE can detect targets at 100km - sounds like wishful thinking to me - but who knows

 

I wouldn't confuse PIRATE with what the F-4B was using, you're looking at a massive change in the equipment being used. Compare how early AiM-9s tracked targets and the staring array used in the -9X and ASRAAM.

[+MigBuster]

I wouldn't confuse PIRATE with what the F-4B was using, you're looking at a massive change in the equipment being used. Compare how early AiM-9s tracked targets and the staring array used in the -9X and ASRAAM.

 

Well yeah - I would hope there is a slight improvement in IRST tech over a 50 year period - but even so detecting a MiG-29 at 100KM? maybe flying away in burner perhaps?

[+streakeagle]

The effective range would depend on the environment as well as the target. Clouds are made of water which block, reflect, and radiate IR energy. At high altitudes with cold clear skies, IR would work very well, especially against targets flying at high speeds with heat not only from their engines but from friction. IRST is a tool commonly found on interceptors. The F-4 and F-14 were both fleet defense interceptors. The F-102 and F-106 were continental defense interceptors. Interceptors in all of these cases meant stopping high altitude and/or fast Soviet bombers and/or cruise missiles. While radar has much better range and isn't blocked as much by clouds, IR is passive and much higher resolution. Before the age of uncaged IR seekers, it was also a good way to find and track targets for IRMs which could then be steered in acquistion parameters. In broad daylight with clear skies, the human eye is more than adequate, but at night is when IRST really shines as a useful sensor. But modern Thermal Imaging which provides a video rendition of the target is much more effective at providing the same service.

[exhausted]

So would the IRST of a century fighter be able to send commands to a heat-seeking missile launched like a radar would to a SARH missile?

[+Crusader]

I think the IRST on the F-4 was kicked out before Sidewinders with SEAM have been available.

On the F-8D/E/J, it was possible with SEAM Sidewinder ( and the aircraft configured for it ) but indirectly

IRST slews RADAR -> slews missile seeker

There was no direct IRST slews missile seeker function, AFAIK.

[+Gepard]

I dont know very much about the US system. But perhaps a short view to the TP-23 of the MiG-23MF. It had a scanarea of +/-30° horizinal and +2/-13° vertical. The maximum detection range of a bomber size target (16 square meters) was 35 km under good weather conditions. A range measurement was impossible.

The system was intended for a "silent" intercept of incoming bombers. The MiG-23 should have directed toward the target by ground controllers, then the MiG should accelearate to come in shooting position and fire. the advantage of this way of interception was, that the intercepted enemy would have no warning by RWR until the missile is launched.

For offensive fighter operations a IRST is not really usefull. The F-4 main objective was rather offensive then defensive, thatswhy the IRST system was not so important for the Phantom.

[+streakeagle]

The missiles of the time were slaved forward, but the IRST gave you a display that let you steer your nose exactly onto the target. Then it was just a matter of waiting for the target to come within range of the missile seeker. Radar would eventually have to be used to confirm range unless you got within visual range. The F-4Bs original purpose was to intercept bombers with the mission specified as "fleet defense", which is rather defensive. The USAF F-4D added a lot more support for ground mapping and bombing, making it a much better multirole aircraft. The F-4E not only added the internal gun and slats, but had an even more capable radar and weapon system for ground attack making it by far the best multirole variant. Whereas the F-4J, like the F-4B before it, was focused on providing the best possible interceptor until the F-14 could be delivered. Of course, thanks to digital technology, the F-4J was at least as capable as the F-4D in the ground attack mission. IRST was less important because radar was starting to work really well, even in lookdown situations and the weight and space it would occupy was much better spent on ECM given the SAM threats encountered in Vietnam.