PSA: How the Hornet's IFF works currently

I saw this video on Hoggit and thought it would be worth showing it here, it taught me something I didn't know that really helps explain the inconsistent IFF that I've seen in the Hornet and might help prevent some friendly fire - the IFF status is only accurate if the target is within the pitch ladder (afaik that's not how it is in the real thing, guessing that's just an EA limitation).

Credit to aceofspades:

(afaik that's not how it is in the real thing, guessing that's just an EA limitation).

Correct. The real life APX-111 CIT limits are ±70° in azimuth and -30° to +60° in elevation.

Some sources say ±60° in azimuth, but it's probably similar to how the radar can scan "±70°" but at different elevations the field of regard is compressed. (ex. the antenna can only scan roughly ±63° or so at higher elevations)

Great find. Looking forward for a correction of this behaviour however.

The jet we have was manufactured in 05ish but it's been heavily upgraded. Other then maybe the software suite and EGI, we pretty much have the definitive navy legacy hornet.

So yes I would think so.

Would the APX-111 interrogator be on a 2005 vintage Lot 20 Hornet, is is the freeze point for this study sim? Probably not, since it was still in testing from 2013 - 2015 and intended for Super Hornet/Growler.

APX-111 replaced the APX-100 on older F-18s between 1997-2000. The latest Hornets (2007+) received the APX-117/118 upgrade which replaced the TX/RX unit, while retaining the antennas/beam forming network from the APX-111. So, its safe to say that the field of regard limits are the same for even the newest Hornet IFF.

Of note, the F-16 block 50/52 use a slightly altered version of the APX-111, the APX-113, which was received starting in 1999. So from a dev perspective the functionality and underlying logic should be the same.

https://www.forecastinternational.com/archive/disp_pdf.cfm?DACH_RECNO=144

https://www.forecastinternational.com/archive/disp_pdf.cfm?DACH_RECNO=170

please don't flame me if this is a stupid question....but.....

currently the IFF on the UFC is disabled (for entering Mode 3 and I read somewhere (NATOPS?) you can even change the mode 1 & 2 from here as well?). The mode 4, (I think) is controlled from the right hand console where your elbow is!

Following the links provided above, the APX-111 can interrogate ALL modes & codes (1-4), yet if in DCS if we cannot set any of these codes (or go silent with them?) how is this airborne IFF working?? (against other "human" piloted Hornets anyway)

so my really dumb question is:

Is the Diamond/square symbology being generated by IFF interrogation or by NCTR (non cooperative Target Recognition) function within the APG-73 radar itself?

I assume the DCS F-15 uses NCTR for head on aspect targets to provide the pilot with an ID. Is that what we are seeing here with the F/A-18? so that ONLY a target, with a head on aspect (therefore "likely" to be within a narrow head on field - such as the HUD ladder ) will generate a Positive Friendly response. In post #1's Youtube video, I think the targets set up have a head on aspect, does the system therefore default to all UNKNOWNS as Hostile until NCTR says otherwise???

I'm not looking for sensitive info, just an Open Source reply (even if it is to "politely" :) tell me that I am completely barking up the wrong tree.

Thanks

please don't flame me if this is a stupid question....but.....

 

currently the IFF on the UFC is disabled (for entering Mode 3 and I read somewhere (NATOPS?) you can even change the mode 1 & 2 from here as well?). The mode 4, (I think) is controlled from the right hand console where your elbow is!

 

Following the links provided above, the APX-111 can interrogate ALL modes & codes (1-4), yet if in DCS if we cannot set any of these codes (or go silent with them?) how is this airborne IFF working?? (against other "human" piloted Hornets anyway)

 

so my really dumb question is:

 

Is the Diamond/square symbology being generated by IFF interrogation or by NCTR (non cooperative Target Recognition) function within the APG-73 radar itself?

 

I assume the DCS F-15 uses NCTR for head on aspect targets to provide the pilot with an ID. Is that what we are seeing here with the F/A-18? so that ONLY a target, with a head on aspect (therefore "likely" to be within a narrow head on field - such as the HUD ladder ) will generate a Positive Friendly response. In post #1's Youtube video, I think the targets set up have a head on aspect, does the system therefore default to all UNKNOWNS as Hostile until NCTR says otherwise???

 

I'm not looking for sensitive info, just an Open Source reply (even if it is to "politely" :) tell me that I am completely barking up the wrong tree.

 

 

Thanks

None DCS Module has an real IFF implementation right now. It is a simple check if the Aircraft is in your own coalition = friend or in the enemy coalition = foe. The FA-18 implementation is very basic and WIP at the moment, because you don't need to hard lock an Aircraft in other modules to know if it's friend or foe.

Keep in mind, that modeling a "detailed" IFF is likely touching areas that are usually classified.

Though there may be enough information available, a company may not be allowed to do this...

... and as Wags as stated here and elsewhere, there are levels of detail that will never make it into the Hornet module based on security concerns. No matter whether or not the information is "out there" if it's classified, it's not going into the model. ED is not going to roll the dice and play that game.

The worst part is figuring out what is (and is not) classified. Still. As you say, it's 'out there', but that doesn't mean a thing. I've always tried to fail on the side of caution so the ream of security termination paper I signed doesn't come back to haunt me.

I can neither confirm nor deny I served in a naval force in the distant past, shortly after the invention of water...

IFF is one of those things that's easily simulated without being modeled.