some SPI (GM, TGP) questions from an A-10C veteran

[twistking]

Hello,
i'm still learning the Viper and have some more questions that i havent't seen answered neither in the manual nor in one of Matt Wagner's videos.

1. Sometimes the TGP won't follow the GM cursor (GM is SOI). Clicking the TGT button on the TGP slews it to the GM cursor (SPI). I wonder where the TGP was looking before that? Why does the TGP not always slave to the SPI? Is there an indication in the TGP that tells me, if the TGP is looking at SPI or somewhere else? What's the purpose of the TGT button (should this not be the default behaviour)?

2. Sometimes the TGP does not Snowplow, even if i ordered it to SP. SP is highlighted on the TGP MFD but the Pod is somehow still creating a SPI somehwere else (seen on the HSD). I had this issue after ordering GM (radar) to snowplow. I basically wanted both GM and TGP to snowplow, but only GM did actually snowplow while TGP was looking somewhere else (not Steerpoint) and creating a SPI...

3. If i want to designate a SPI via the HUD (or HMCS) do i need to use a weapon profile that specifically enable this? I wanted to designate a SPI for an CCRP GBU-12 release with the HUD and fine tune with TGP, but could not get this to work. Any ideas? Workarounds?

Thanks for all your advice

Edited December 30, 2021 by twistking

[RuskyV]

1 hour ago, twistking said:

1. Sometimes the TGP won't follow the GM cursor (GM is SOI). Clicking the TGT button on the TGP slews it to the GM cursor (SPI). I wonder where the TGP was looking before that? Why does the TGP not always slave to the SPI? Is there an indication in the TGP that tells me, if the TGP is looking at SPI or somewhere else? What's the purpose of the TGT button (should this not be the default behaviour)?

My understanding is the TGP needs to have a steer point or mark point to look at if not in SP mode, when you find a target in GM and hit the TGT button you are asking the TGP to look at the same coordinate. When you move the cursor in GM you are not altering the SPI rather just shifting to a new coordinate. Any time you move the TGP when SOI you will build an offset from that coordinate (or the one you last looked at). When designating a new point or coordinate you will need to remove that offset by hitting CZ (cursor zero) otherwise you will carry that offset to the new designated point.

i could be wrong here but from my understanding, you cannot separate the SPI from either a steer point or waypoint like in the A10c. When you move the TGP from a location you are telling it to look so far in direction from that given point, there is no SPI under the cursor of the TGP if this makes sense? This is why you need to make good use of the CZ function.

2 hours ago, twistking said:

2. Sometimes the TGP does not Snowplow, even if i ordered it to SP. SP is highlighted on the TGP MFD but the Pod is somehow still creating a SPI somehwere else (seen on the HSD). I had this issue after ordering GM (radar) to snowplow. I basically wanted both GM and TGP to snowplow, but only GM did actually snowplow while TGP was looking somewhere else (not Steerpoint) and creating a SPI...

 

I'm not sure if this should work (someone else might need to jump in here) but the TGP needs to be either looking at a steer point or mark point, the GM radar and the TGP don't appear to be directly tied to each other so manipulating one sensor will not automatically move the other to look in that direction. 

2 hours ago, twistking said:

3. If i want to designate a SPI via the HUD (or HMCS) do i need to use a weapon profile that specifically enable this? I wanted to designate a SPI for an CCRP GBU-12 release with the HUD and fine tune with TGP, but could not get this to work. Any ideas? Workarounds?

Again ill take a stab at this and say you would need look at what you wanted to target then drop a mark point down and TMS up twice to stabilise and mark that location in order to put a sensor on it, as you are not moving the SPI under cursor, be it the TGP or the HMCS. 

hope this helps a little, I'm sure someone will put us both right

 

[SCPanda]

1 hour ago, RuskyV said:

Again ill take a stab at this and say you would need look at what you wanted to target then drop a mark point down and TMS up twice to stabilise and mark that location in order to put a sensor on it, as you are not moving the SPI under cursor, be it the TGP or the HMCS. 

hope this helps a little, I'm sure someone will put us both right

 

With JHMCS AG mode now, I don't even bother with dropping a markpoint, since you can see where your TGP is looking on JHMCS. What I found to be very effective is just slew the TGP to where you want to setup SPI with the visual aid of your JHMCS, then just area track or point track on TGP to setup that SPI. This is also more accurate than dropping a markpoing with HUD or JHMCS since you can track a specific target on your TGP. But yeah, I guess you can also drop the markpoint with TGP. 

4 hours ago, twistking said:

3. If i want to designate a SPI via the HUD (or HMCS) do i need to use a weapon profile that specifically enable this? I wanted to designate a SPI for an CCRP GBU-12 release with the HUD and fine tune with TGP, but could not get this to work. Any ideas? Workarounds?

Like I said above, just slew your TGP with the help of your JHMCS (or HUD if the target is in front of you), find and track your target using TGP, then go for the CCRP GBU-12 release. It's honestly very fast and easy to perform with AG mode on JHMCS now. 

[Frederf]

1. F-16 has a "single LOS" design which makes pointing the radar and TGP in different places functionally impossible. The three typical sensors which can slew the TD box are: the HUD, FCR, and TGP. When any of these sensors is selected and slewed the other two break track and slave LOS to the master sensor. One is able to freely cycle between these sensors as SOI and the others will immediately break track and slave. The only exception is that TGP waits to break track until you actually slew the other sensor (not just when SOI changes). The TGP is being at the last place it was left before it gets a message to slave. This message to slave is being generated for one frame on sighting point rotary change or cycling master modes or some other major change which causes the system to reevaluate. This should not happen as the message to slave is continuous and automatic.

The "TGT" label is the sighting point rotary which lets you cycle through available sighting points. It should not cause anything special to when TGT is the only sighting point in the list because "TGT" to "TGT" is no change at all. As explained above even if "TGT" to "TGT" would count as a change, there would be no noticeable effect as the TGP slaving would be continuous and automatic. Sighting rotary change tells all sensors to break track (slaved and SOI) to prevent slews from being introduced into the system. Notice that if TGP is AREA and sighting point is changed (again, TGT to TGT shouldn't count as a change, but it does right now) TGP is commanded to break track. Notice how it's possible for TGP AREA and FCR SOI and slew to exist simultaneously? Not like that.

You can tell where SPI is by looking for the AG SPI mark on the HSD. In your case it should be the SOI'd radar providing SPI. The TGP being left in the dust isn't.

 

2. Snowplow isn't really something any particular sensor does but the whole airplane. It's mostly based on the radar (even off as range can still be set) with all other sensors forced to that LOS. The "SP" shortcut is accessible on multiple formats but there's only one SP action. This is similar to "CZ" which zeroes out the cursor slews for the whole airplane. The "CZ" shortcut on the FCR/TGT/HSD  (HSD on OFP 5+) are just multiple places to trigger that one action. I notice the FCR SP and TGP SP are acting independently which is significantly different than airplanes both older and newer than the DCS one. SP should also blank the sighting point rotary slot at OSB10 or write "SP" in newer OFPs. You can use OAPs with SP but they have to be reselected if on before. VRP/VIP does not allow SP. In SP pre-designate there is no SOI (neither MFD nor HUD). The system awaits a TMS forward press to designate the SP pseudosteerpoint and then moves SOI to the priority display automatically.

 

3. Yes and no, kinda. In NAV any slewing is slewing the navigation solution while in any preplanned attack mode any slewing is slewing the target designator (well, sighting point but same thing) position. Of course slews in NAV carry over to AG preplanned and vice versa (except SP, mark, IP/RP, fix). Pick a visual only weapon like STRF or rockets and it gets different. Apparently you can make FCR GM in STRF (not sure you should be able to) in which case you are moving nav solution (diamond) which is moving SPI.

Specifically about GBU-12 assuming you're in CCRP, yeah no problem seamlessly moving between FCR/TGP/HUD as the SOI. I didn't find any difficulty in the current version. Sadly DTOS is a visual submode which forces AGR and TGP to AGR LOS. Hopefully post-designate DTOS we'll be able to cycle over to CCRP and use the post-designate DTOS point as the basis for CCRP attacks (refining with other sensors as desired). But I'm not sure if that's how that works.

[twistking]

thanks to all, but especially to @Frederf for this super detailed explanation. i need some time to digest all that info and will try it out in the sim. i'm pretty sure that i encountered a bug though: while snowplowing in AG the SPI does not snowplow. i confirmed radar and TGP plowing ahead, but i would still have a SPI somewhere static (i think on the position the SPI was before entering SPlow).

What i still do "miss" from a workflow point of view, is an easy way to "recage" the SPI to HUD or HMCS, like it is possible in VIS mode. I would like a similar way of doing it with other modes, like CCRP, PRE etc. That's the reason i started fiddling with SPlow in the first place...
Say you have your TGP looking somewhere and generating SPI in CCRP mode. You suddenly notice a target on the other side of the aircraft. Slewing the SPI is not fast enough and can make you loose situational awareness while slewing. Changing the weapon profile to VIS and designate with HCMS would work better, but requires a lot of buttons that are not HOTAS. Also you'd need to carry a VIS capable weapon.

In this situation maybe the best way of doing it would be putting down a quick markpoint? You could stay in CCRP. Only one (or two?) button presses that are not HOTAS, but you'd need some more to make the markpoint SPI after creation... I guess i'm spoiled from the A-10c. I just want a quick way to force als sensors on HMCS or HUD cursor independent of weapon mode...
By the way, the scenario that made me want my a-10 back, was a training mission where i hunt down some iranian speedboats with GBU-12s in the persian gulf. They quickly leave the TGPs FOV once point-track breaks. Markpoints don't work neither. Best way would be to update SPI to HMCS LOS on button press, but that does not work with CCRP. Any ideas? My workaround was to use SEA radar to designate general direction and fine-tune with TGP, but that's not ideal once you're close in, because radar FOV is relatively narrow obviously...

*edit* disregard the last part. If i understand it correctly, what i am asking for is DTOS mode, which should be coming soon.

 

Edited December 31, 2021 by twistking

[SCPanda]

29 minutes ago, twistking said:

By the way, the scenario that made me want my a-10 back

Well, I guess that's why F-16 and A-10 are tasked with different missions IRL. A-10 is prob more suited for CAS. But we should not ignore F-16's multi role capability. It can fly much faster and higher so it will get you to targets quicker. It can do BVR, BFM, and SEAD. 

 

35 minutes ago, twistking said:

a training mission where i hunt down some iranian speedboats with GBU-12s in the persian gulf

If you are flying the F-16, shooting Maverick D in vis mode is probably a better option. 

[twistking]

6 hours ago, Frederf said:

[...] Sadly DTOS is a visual submode which forces AGR and TGP to AGR LOS. Hopefully post-designate DTOS we'll be able to cycle over to CCRP and use the post-designate DTOS point as the basis for CCRP attacks (refining with other sensors as desired). But I'm not sure if that's how that works.

I'm confused. I briefly thought DTOS would be exactly what i was wishing for. Something like Maverick VIS, but for Bombs. Wouldn't DTOS be perfect for quickly designating a target with HMCS and dropping a GBU on it without doing a markpoint first?
I found a video on youtube from that other sim and for me it seemed to work like VIS but with CCRP delivery after designation. What problem do you see?

[Frederf]

SPI is always place in the real world, as in latitude-longitude-elevation. Wanting to "recage SPI to HUD" is a nonsense idea when viewed this way. Even in situations where it feels like the SPI should be untethered to the Earth like predesignate SP, predesignate DTOS, CCIP, etc. the SPI is actually somwhere in real space, usually at the steerpoint. I understand the motivation though. You want to "initiate a preplanned attack from a visually-designated arbitrary point" IPAFVDAP for a completely made up shorthand.

At its heart the F-16 is a strike fighter and locations in preplanned mode are relative to steerpoints. Only visual mode is untethered (ultimately deprived of enough tools even visual will reference steer data for elevation). IPAFVDAP is against its nature. It can be frustrating if that's what you want. Snowplow is an interesting mode because the designated point is the pseudosteerpoint, a temporary steerpoint which has its own temporary deltas. It fullfills the dream of preplanned attack relative to an arbitrary point, but without the visually-designated part. It's awkward to place without fancy helmet integration or even predesignate slewing.

Re: DTOS. It absolutely works like you say. What I am not sure is possible is DTOS designate then changing to CCRP. I'm not talking about the CCRP-like behavior of post-designate DTOS but actually switching to full CCRP. Then in actual CCRP using the DTOS designated point as a sort of steerpoint for further refinement. If you could carry over the DTOS designated point into preplanned this would be a method of IPAFVDAP.

When marks get sorted out using a mark as a basis for IPAFVDAP is going to be a lot more fluid.

A-10 famously has lots of IPAFVDAP abilities. It can use the TDC through HUD or with helmet simply command TGP directly.

For ship hunting I can't think of a better method than SP to designate pseudosteerpoint close as you can, slew over ship then transition TGP when close. That's not so bad because you're acquiring target on radar initially. What's hard is correlating a visual acquisition to radar especially with how clunky SP is. My understanding (huge caveat) is SP is an odd duck historically and rarely used and seemingly neglected. Heck the whole graphical radar is rarely used. They use SP for weather radar. I wouldn't be surprised is the average DCS user uses SP more in a week than a real pilot in whole career.

[twistking]

22 minutes ago, Frederf said:

[...]

Thanks again for the insights. I think i understand it now and you are exactly right: IPAFVDAP is what i want (it's in my soul / it's what i need).
I'm confident though that DTOS will be "good enough" for me. (maybe i simply want IAFVDAP - without the first P) Even if you could not translate to preplanned/vanilla ccrp, i'd get a way to drop an gbu-12 on a visually designated point. For mav and jdam i have VIS and everything else is good in ccip.
In a way i really like, that the F-16 is so streamlined and "strike-oriented", it was just the fact that there was no visual option at all for a ccrp-type attack.

Edited December 31, 2021 by twistking