Possible active radar missile bug (very serious issue)

[molnibalage]

I’m almost 100% sure that active radar missile are 100% immune against chaff which means a major bug. I tested AC radars with 0.99 chaff chance value with AIM-7 and happened what I expected. Single chaff was able to break radar lock and caused a miss. I created a 3 x 3 F-15C TE and all missile defeated easily on bothd sides regardless of distance or relative position.

I set the same 0.99 value of AIM-120 and runned the same TE. Regardless I dropped dozens of chaff within 1-2 sec missiles never lost the lock on me and of course AI also was not able defeat any AIM-120 with decoys. I think the results are very definite.

I’m not sure but as I can remember OF had different chaff from BMS4 has currently. During the developing FF I found 100% same issue in a beta version of FF. FF devs changed the chaff and caused somehow the bug. What a coincidance, isn’t it?

I can record tests with many different missiles and AC if it is required.

[Arty]

Could u please tell us which value u changed where so to test it also?

[molnibalage]

Radar data of AIM-120 in database. Radar data 4. Original chaff change 0.05, I changed to 0.99.

(I used my MOD but AIM-120Bs use the same radar data as in core DB.)

[Dee-Jay]

Is your AIM120 in “active” mode without a/c’s radar support? Did you tried in “BORE” mode as well?

[molnibalage]

I launched AIM-120 with TWS and dofight STT radar lock either. Yes, missile was active because I tested not only against AI I was target either during all tests.

[Fenrir]

Does it matter how you deploy chaff or is it just the fact that you deploy them that make the radar to loose lock?

In my mind i think that you have to get the chaff between yourself and the missile to have any effect.

Do you know?

Cheers

[molnibalage]

Does it matter how you deploy chaff or is it just the fact that you deploy them that make the radar to loose lock?

I do not know the effect of release iterval but I have tested many times sensors. Even if RI has effect the relative position is much more importand. During a hard turn seems to me more effective the chaff as in level flight. This is also true for flare.

[Dee-Jay]

Try without any a/c radar lock please. (try BORE)

[molnibalage]

@Dee-Jay:

Try without any a/c radar lock please. (try BORE)

Just launch the missile toward to a possible target? I can try but in all other Falcon version AI did not reacted missile which were launched without radar lock.

[Dee-Jay]

@molnibalage:

Just launch the missile toward to a possible target? I can try but in all other Falcon version AI did not reacted missile which were launched without radar lock.

Try MP

[molnibalage]

@Dee-Jay:

Try MP

I will ask some guys to do it. I tested against AI, same dumbness as in other versions there is only a minor difference. When radar on missiles are turned on use the dispenser only once, but perfom 0 evasive actcion, in BVR simply continue the approach. –-> Maddog mode should not be used against AI, another bug.

[Guest]

I’m guessing it’s quite possible with the new ARH missile mechanism introduced in BMS4 that the missile radar no longer obeys the countermeasure laws introduced in RP5. Maybe the radar data section in .rcd file simply no longer has any effect… (given the correct tests are done that is.)

reason, an example: according to BMS-34, the range gate for MPRF and HPRF are defined in missile FM dat file, and for AIM-120 they’re in code. Obviously the AIM-120 goes HPRF well above 10nm, but the onboard radar range in falcon4.rcd #4 is only ~9nm. So HPRF radar, hence probably MPRF radar property is defined elsewhere if at all, and maybe without a chaff chance in that data field. Or maybe the chaff chance is indeed linked but something is preventing it to have any effect, and since the chance is so low to begin with nobody ever notices it. Just my guess tho apparently.

Some time ago I loaded the F-16 with 1000 chaffs and a countermeasure profile of 50 chaffs per slap switch smash. I was never able to break the lock of an AMRAAM while in openfalcon there was some 50/50 chance. But I didn’t change the radar’s chaff chance and forgot about the issue later on. Although I did get my desired learning objective: when “M” visible, run and save the chaffs

[haukka81]

Amraam is way to good in this sim, and way bad in FC3 Maybe something in between those would be nice.

[molnibalage]

@haukka81:

Amraam is way to good in this sim, and way bad in FC3 Maybe something in between those would be nice.

Even if somebody fix this bug likely the chaff characteristics of ARH - which was defined by RP5 - still remains which means hard to set a balanced model for ARH.

[Amraam]

@haukka81:

Amraam is way to good in this sim, and way bad in FC3 Maybe something in between those would be nice.

From what is based your theory?
Real F-16 driver as already report that even AIM-120B is much more deadly IRL. The simple fact that AMRAAM is bugged to high altitude launch is well know (real one have much more kinetic range).

[molnibalage]

Real F-16 driver as already report that even AIM-120B is much more deadly IRL.

In RL combat so far has not been faced with advanced enemy which has ECM, huge quantity if dispensers, SOJ support, etc… How you can translate the “more deadly”? Kinematic range of AIM-120B is very similar to AIM-7M. Burn time of engine is smaller, but drag of AIM-120 also small, the brunout speed is very similar, but total engine running time of AIM-7M is 5+11 sec and not ~7.5 sec. Deacceleration of AIM-7M is faster but happens later.

What bout sensors? Because the kinematics + sensor capabilites represet the quality of the missile.

[Guest]

well if anything there’s no mechanical/electrical malfunctions modeled, as well as complicated ecm stuff. but again in RL there’re no bugs and CTDs so i digress…

[Amraam]

I don’t speak about ECM, ECCM, SOJ ect…
I speak about the FM of the missile. Currently above 25.000 ft, you don’t have any significant advantage of range. Falcon is not so far of real data in low level and medium level range. But above 25.000ft, you have a well know issue. IRL you can increase the range between 50% and 75% above 30.000 ft. And I speak only for the AIM-120B.

[Guest]

@Amraam:

real one have much more kinetic range

i’d guess the bms amraam does have the range just the DLZ is off… because with correct atmosphere modelling and correct med-low alt performance, no reason for it to be off up high, simple physics/math. so at least the aerodata and engine thrust section in the FM (the most important part) is OK, only need to fix the DLZ.

another possibility is real missile uses some more advanced guidance like dynamic loft. for example, when firing at 5k, no need to loft the missile much, you’re only increasing travel distance. but when firing at 30k, no reason not to loft the thing up to 55k and come back down to use the much thinner air up there. that BMS ofc doesn’t model…

a conspiracy theory… in OF aka MLU M2 avionics, we had a loft cue between Raero and Ropt. in BMS4 aka MLU M3 avionics, the loft cue was gone. maybe just maybe something changed in the amraam guidance to incorporate the lofting itself

[Blu3wolf]

you’d guess huh?

I recall hearing that the atmospheric modelling does not take into account the difference in the size of the rocket plume at different altitudes, nor the difference in thrust it makes.

IMO (unqualified ofc) its not the DLZ that is at fault.