SPO15 feedback

[Muchocracker]

3 hours ago, okopanja said:

Yes, but did the SME have access and experience with the actual device? Unlike the first SPO analysis, the second one went much more in depth and even offers several possibilities (a nod to the SME for his effort), yet with present knowledge I would say it's neither definite yes or definite no.

How is a full analysis of wiring diagrams showing that nothing but the FH blocking signal pins were even wired for the MIG-29 model that was chosen not definite? 

[okopanja]

13 minutes ago, Muchocracker said:

How is a full analysis of wiring diagrams showing that nothing but the FH blocking signal pins were even wired for the MIG-29 model that was chosen not definite? 

Did you actually read it?

[Dejan]

I wonder, do we have all the documentation and schematics for the magical RVR on the F-18? Or is it just "take my word for it"?

[Harlikwin]

7 hours ago, Muchocracker said:

Nothing about these quotes really refutes anything in the analysis made by ED's SPO engineer. 

Well then, allow me to retort.

The claim that the SPO-15’s blanking pulse is “40 ms” almost certainly comes from a typographical or font-usage issue in Soviet manuals rather than an actual technical specification. In Russian documentation, microseconds are written as “мкс,” but the middle letter к was often rendered in a way that made it easy to overlook, leaving “мс,” which denotes milliseconds. The same kind of unit confusion appears in other Soviet-era technical materials, such as infrared sensor manuals where “3–5 µm” was printed as “3–5 mm.” For the MiG-29’s N019 radar, which has a pulse-repetition interval on the order of 50–100 microseconds, a 40-millisecond blanking period would be impossible and would effectively blind the RWR. Such a long blanking window would also make the SPO-15 unusable with older, lower-PRF radars like those on the MiG-23 or Su-24, yet the system is known to function normally with them. A 40-microsecond blanking pulse is therefore the only technically plausible reading, making a unit typo the far more likely explanation.

ED's  entire argument rests on the assumption that the SPO-15’s internal blanking system uses blocking intervals of “tens of milliseconds,” but this comes from a unit misinterpretation rather than an actual specification.  In reality the system was designed for microsecond-scale blanking, consistent with the pulse timing of the MiG-29’s radar and with other Soviet aircraft where the SPO-15 is known to function properly. Once this unit error is corrected, the premise that the device expects millisecond-long blanking windows—and the conclusions drawn from it—no longer hold.

Like its quite obvious the radar can use microsecond scale timing, even older radars could, so why in gods name would they design the SPO blanker in this fashion?

Regarding the synch line;
The section about the N019’s synchronization signal correctly shows that only a single “L006 blocking” line connects the radar to the SPO-15, but it misinterprets what that implies. Soviet and Western RWRs of the same era were all designed to use exactly one blanking input tied to the radar’s transmit event, so the presence of a single line is entirely normal. Labeling it a “one-time command” is just the standard Ts100.02/N001 control convention and doesn’t suggest any limitation. The SPO-15’s internal gating circuitry on board 51 was built around this exact architecture and worked on MiG-23, Su-24, Su-27, and MiG-29 without needing additional wires or mode-specific synchronization signals.

The claim that the SPO-15 cannot synchronize because the BTsVM is too slow is based on a misunderstanding of how the system actually works. It assumes the onboard computer must generate pulse-by-pulse blanking timing, but the BTsVM was never responsible for that. In the N019, as in Western radars of the same era, the real-time blanking waveform is produced directly by the radar’s analog synchronizer and transmitter hardware, while the “one-time command” line from the BTsVM is simply a mode-control discrete that enables or disables blanking. The RWR’s internal gating circuits handle the actual synchronization with the radar pulses. Because the BTsVM is not in the timing chain at all, its loop latency and bus delays are irrelevant, and the conclusion that synchronization is impossible does not follow. This is consistent with the fact that the SPO-15 worked normally on MiG-23, Su-24, Su-27, and MiG-29, all of which relied on hardware-level blanking rather than CPU-generated timing.

[Ronin_Gaijin]

7 hours ago, okopanja said:

Yes, but did the SME have access and experience with the actual device? Unlike the first SPO analysis, the second one went much more in depth and even offers several possibilities (a nod to the SME for his effort), yet with present knowledge I would say it's neither definite yes or definite no.

On the other side the testimonials/interviews (I would not call them anecdotes), but I did a fair deal of detailed research into the topic:

E.g. Boro Zoraja flight is described here, and it even contains rough reconstruction of his flight. Sadly the opposing pilots did not give interviews, and if someone is aware or could correlate please let me know. 

Also for the same event pilots gave several interviews, often providing additional information. Collecting them all of them, correlating, verifying against multiple other sources including similar material of opposite side is a matter no simpler than the analysis of circuit boards. 

In addition a number of books, monographs and publications on these flights were published on this matter. I do have access to some of them but not all of them, and some actually sold out rather quickly, since the publishers did not anticipate the interest of the general public. 

In addition there are a number of controversies about commanding officers and decisions they made during the war. In particular it appears that the commander of the Air Force and PVO at that time gen. Spasoje Smiljanić (a person placed into his position to replaced gen Veličković who was not considered as loyal enough Milošević) did not treat the pilots with the respect and integrity. In fact he actively worked after the war to suppress them (including kicking out at least one of them) and justify the failure of the Air Force to shot down enemy aircraft, by forcing the conclusion that the pilots well not trained well enough. When reading the interviews of US pilots who were their opponents, I did not find that their training was faulty, especially given the fact how close the 29s got close to their opponents, despite the numerous electronics failures. If anything these people deserved recognition and respect.

As for late lt. col.(colonel posthumously) Milinko Pavlović, his flight is by far the most difficult to analyze. He was the commander of  127th Fighter Espadrille within 204th Fighter Aviation Regiment. From the first day he faced extreme pressure from gen. Smiljanić to achieve results in face of more numerous, better equipped enemy. Still due to the situation with majority of airfields being severely damaged, and the fact that very few aircraft were left in flying condition, gen Smiljanić did issue order not to scramble the remaining ones. 

On the day of the flight on May 4th 1999, this order was still in effect, until Operational Center ordered Pavlović to prepare and scramble the single fighter from Batajnica airbase. To this date I did not find the information who made this decision which was in strong contrast to standing order of Smiljanić. At the time of the scramble order, the unnamed young Mig-29 pilot was on flight schedule. Pavlović who was at command post ~4 km  away from airport, made a call to the direct post at airport and told them to prepare the aircraft but not to scramble the aircraft until he arrives. He left his deputy at command post and jumped into the private car which he drove directly to the location where Mig-29 was being prepared with younger pilot already strapped in the cockpit. Upon arriving, he ordered the young pilot out and took his place. This on its own was a breach of procedure.

From this point it is rather difficult to establish what actually happened during the flight. We know he flew to defend town of Valjevo (he was born in the nearby village). We also have reports of missiles heading toward him from direction of Bosnia, but also missiles flew from our own PVO positions. Witnesses claimed the enemy missiles hit the aircraft, followed immediately by hits from our own. Milenković did not eject and was likely killed in the cockpit. PVO never confirmed that they shot, but from testimonies of other flights red-on-red did happen several times during the war. 

We do not have direct testimony, but rather of his deputy who provided his last words. I do believe that Air Force and VOJIN did record the conversations. It should be noted that this is the only flight where we do not have a live pilot surviving the flight, likely even the Air Force does not fully know how this event fully unveiled.

Additional sources are more than welcome.

 

A game beta tester calling a real life pilot statement as an anecdote is the anecdote itself. 

[Schmidtfire]

51 minutes ago, Dejan said:

I wonder, do we have all the documentation and schematics for the magical RVR on the F-18? Or is it just "take my word for it"?

What has that to do with the SPO15? The AN/ALR-67 is a vastly more advanced RWR that integrates with other defensive systems on the jet. They probably don't have full access to the documents and schematics for it. But it's still created off open sources and SME feedback.

The SPO15 is not a great system by any means. Even SME's who used it states it was confusing to the pilots. It was common to fly with the sound volume tuned down.  It's also known the SPO15 was configured to only detect launches from Nike Hercules, so it it was good for not being clapped by long range SAM's.

Add to that, ED development team are fans of the MIG29. They have put a lot of taught behind their implementation to get the SPO15 as accurate as they can, using the available schematics. I can not say if they missed something, but they are trying to stay true to the accuracy on this one.

This is just my personal reflection, but I doubt the SPO15 were nearly as important instrument IRL as in DCS.

[Harlikwin]

41 minutes ago, Schmidtfire said:

 

This is just my personal reflection, but I doubt the SPO15 were nearly as important instrument IRL as in DCS.

Yeah, but the problem is that we don't have those other "helper systems" like GCI in DCS, and likely never will in any robust fashion. Also, even modern ALR-67's have drawbacks and issues that are not "presented" in DCS. So its the case of One standard for this, a totally different standard for that which is what I think people are really having a problem with. Its the same story with other systems like radars on  various modules, some are good, others well, less so. 

[Schmidtfire]

1 hour ago, Harlikwin said:

So its the case of One standard for this, a totally different standard for that which is what I think people are really having a problem with. Its the same story with other systems like radars on  various modules, some are good, others well, less so. 

Yes I understand, but it's a different discussion. The wish is for ED to make a modified SPO-15 that's more in tune to "DCS World reality" is already in the wishlist section. 

The only thing that should be judged in this thread is if the SPO-15 is behaving as accurate as possible given available technical documents and SME feedback. Clearly more data is needed if you believe ED's implementation is incorrect. A first step would be to find an SME (pilot or technician) that can give more details. Perhaps on the German or Polish forums?

Edited 1 hour ago by Schmidtfire

[Muchocracker]

5 hours ago, okopanja said:

Did you actually read it?

Did you?

 

Quote

The method of integration between the L006LM and N019 can be deduced from the wring schematics. The only electrical signal related to blocking/blanking that is connected in the 9-12 is pin 4 of connector 7 - Blocking Band I, Forward Hemisphere. This signal is also identified explicitly (as “блокировка изделия Л006 первого диапазона передней полусферы”) in the radioelectronic equipment manual for the 9-12, in the L006LM section. The signal can be seen here, in a German version of the wiring schematics (empty ports and pins are omitted in this version), we have also determined elsewhere that connectors 10-14, which are necessary for blanking, are empty by design and not arbitrarily omitted here. The same applies to the blanking pins in Connector 7.

 

[okopanja]

3 minutes ago, Muchocracker said:

Did you?

Sure I did, and you?

[Muchocracker]

3 hours ago, Ronin_Gaijin said:

A game beta tester calling a real life pilot statement as an anecdote is the anecdote itself. 

Wiring diagrams describing hardware functions is a higher level of evidence than anecdotal statements made by an SME. This isnt a hard concept to understand. 

[Thirsty]

1 hour ago, Harlikwin said:

So its the case of One standard for this, a totally different standard for that which is what I think people are really having a problem with. Its the same story with other systems like radars on  various modules, some are good, others well, less so.

 

That summs up most people I agree,
I would even go as far everyone since even the AI knows when they are getting shot at, but not you in the fancy new virutal jet, limiting the usability of what would be a great release for DCS.

And I may add, I never said even once that they should put launch warnings into the SPO-15. Insted remove the launch warnings from their Magical RWRs(15,16,18, M2K etc ) that picks up things that it shouldn't.

But as for now, you don't even know that you are getting locked, what is weird since every SME I heard speaking about the SPO-15, they said that the air threat identification was absulutly useless, it was better for SAMs however.
but they know for sure if they were locked or not, even with the radar emitting.

Meanwhile all the other side is saying such things like "oh, it is the start, every other module will be up to this standard one day"

That's the issue "One day", that would realisticly can take over many, even over 5 years. 
Since for sure ED will not stop developement for their new upcoming cash bringer such as the F-15C and the F-35 just to go ahead and make all RWR behave realisticly as they should, neither that can be enforced uppon other developers to do so.

And since there is still so many documents about the SPO-15 that is classified, the situation for Western RWRs are probably even worse.
 

31 minutes ago, Schmidtfire said:

The wish is for ED to make a modified SPO-15 that's more in tune to "DCS World reality" is already in the wishlist section. 

At this rate sadly it looks like it is a matter of time until that thread will be it with the 
"Not planned, Correct As Is"

[Кош]

В 13.11.2025 в 17:11, BIGNEWY сказал:

Summary of SPO-15LM synchronization systems

The team have prepared some more information to help understand the systems we hope you find it interesting. 

thank you 

Thank you! Now this is an adult level of conversation I was striving for. From the onset I have to say that wiring diagrams(I saw everything you have posted on my own before) per se don't tell us anything new and don't answer how blocking works, for that we need timing diagrams analisis - I have them but sadly it takes time and I'm a bit saturated with payware tasks at the moment.

So far:

RF binning is used not for spillover but for threat recognition. 40 should be microseconds because milliseconds doesn't make sense with any threat SPO-15 is known to identify. Also, what document cites this number? Is it cited as static or a result of a control law?

Do you know that central computer's IO is refreshed at 2.5 megaherz, despite 100 kiloherz CPU?

Edited 26 minutes ago by Кош

[okopanja]

8 minutes ago, Muchocracker said:

Wiring diagrams describing hardware functions is a higher level of evidence than anecdotal statements made by an SME. This isnt a hard concept to understand. 

I carefully read both SME reports. I acknowledged that second one is more in-depth analysis and also contains several interpretations, some based on assumptions, but still much better, but still it does not feel conclusive.

I also carefully listened and recorded what the pilots said in the interviews: SPO had a prominent role and they considered it a very important source of information, especially since most of them had poor or no GCI guidance. At the same time some of them dodged not only AIM-7 but also the modern AIM-120B and AIM-120C missiles, making it into the merge (e.g Nikolić/Kulačin). It's one thing to practice it in DCS buy trial and error, but these guys did it in real life. I really doubt that they relied purely on the dice rolls and just happen to get lucky.

Due to the need to do corrections and correlation with with other sources, I did not publish all of interviews yet. Some of the guys listened themselves and are also rising the questions here. It appears that as long as the SPO/Radar were not malfunctioning, they actually worked together. You can read yourself the one I have already published and linked.