R-27ET, no LA even though target is in range

Hello,

I am having trouble using the ET in the Su-27.

With a target locked and in range according to the HUD, I am not getting launch authorisation. I have tried using EOS, radar and both on, with no luck. Sometimes it will randomly work, but I have been multiple times right in front of a target, within visual range, and the missile refused to go off the rail. Overriding LA does not seem to work as the missile doesn't track.

Am I doing something wrong or is it a known bug ?

I have noticed that the 27's missiles in general seem to be tough to use against Slammer-armed opponents. The ER has slight range advantage but is semi-active, and the ET can't fire at max range. And avoiding the Slammers is risky business since you get launch warning moments before impact.

For example, I've tried the HVA hunt mission for the past two days and only managed to down the AWACS once, by pure blind luck. All the other times the F/A-18s would splash me before I could down all of them. I thought the ET would be a good response but as I said it isn't working for me, and you can only carry two of them while the 18s have actives on every pylon.

The ET is not a radar missile so can't be guided by your systems, it is an IR missile so uses its own sensor; a seeker in the nose. This locks onto heat sources so is dependent on how hot the target it is looking at is eg. the rear of an aircraft in full afterburner will give a longer acquisition range than against an aircraft nose on with idle throttle.

The ET is not a radar missile so can't be guided by your systems, it is an IR missile so uses its own sensor; a seeker in the nose. This locks onto heat sources so is dependent on how hot the target it is looking at is eg. the rear of an aircraft in full afterburner will give a longer acquisition range than against an aircraft nose on with idle throttle.

Thanks. I thought that the ET's seeker was slaved to the radar, that certainly explains it. Falcon BMS has spoiled me !

The seeker is slaved to the radar but won't authorize launch until it has it's own IR lock because once it is launched it no longer has any info from the radar.

In BMS you're also technically supposed to un-cage the seeker to check that it is tracking properly. You also don't have an R-27ET to use.

Thanks. I thought that the ET's seeker was slaved to the radar, that certainly explains it. Falcon BMS has spoiled me !

Thanks. I thought that the ET's seeker was slaved to the radar, that certainly explains it. Falcon BMS has spoiled me !

In BMS the missile is still reliant on its own seeker, it is just that Aim-9s are short range compared to the Et so will generally see the target before launch before it is is in firing parameters. As in both sims its not the radar telling it where to fly to rather just where to look before launch.

Hang on, is radar lock required for LA with the ET?? :huh:

Hang on, is radar lock required for LA with the ET?? :huh:

No, Et can be cued with Eos via the scanning, vertical, bore or helmet modes or fired with aiming mode using tone, Fi0 mode.

... or fired with aiming mode using tone, Fi0 mode.

can u describe this in more detail ?

what is Fi0 mode?

i never hear a tone from a R-73 / R-27ET :(

can u describe this in more detail ?

 

what is Fi0 mode?

 

i never hear a tone from a R-73 / R-27ET :(

Also known as Longitudinal Aiming Mode (keyboard "6"), if you're looking for it in the Options Menu.

From the DCS SU-27 Manual:

Fi0 (Fi-Zero) is a backup mode in case of failure of the fighter weapons control system (WCS) radar and IRST sensors. This mode is selected with the [6] key, but can be used only with infra-red homing (IRH) missiles which have seekers capable of acquiring the target independently of the fighter’s sensors. In this mode the missile’s own seeker, which has a 2-degree conical field of view looking forward along the missile axis, is used to lock the target. It’s necessary to maneuver the fighter to place the aiming cross-hair over the target. The LA symbol appears immediately when the missile seeker has locked the target, regardless of target range. The pilot should judge the target range visually to ensure the missile will have enough energy to complete the intercept, especially in the case of receding pursuit targets.

 

The use of infra-red homing (IRH) missiles in the Fi0 mode will not trigger the target’s RWR, and as such can be used to affect a passive "stealth" attack. The target can detect the missile launch only visually.

And, yes, you will get a lock tone in this mode.

EDIT: The attached track demonstrates the size of the missile's field of view while in this mode. I'm targeting a friendly, so, don't take over and release a missile. You can stop viewing when I turn away from the target as there's nothing else to see. The track ran on as I was wondering why my TIR wasn't working...turns out I never turned it on. What can I say? I'm still on my first cup of coffee and age sometimes sucks...

thx ... :thumbup:

i know the mode (key 6), but not the the name Fi0 :)

and i did not use it ....

i will do a try and give an attention to the tone ...

the tone is only available in 6 (Fi0) mode ?

...i will do a try and give an attention to the tone ...

 

the tone is only available in 6 (Fi0) mode ?

I've never noticed it with any other aiming mode. Then again, every other mode gives you visual lock and launch authorization cues. There is none in this mode. Hence the auditory lock cue...that would be my guess.

IRST?

IRST?

Sorry. That's a little too cryptic for me this morning. Not sure what you mean. :)

Yep, that's how it is in-game.

Realistically you should get the audio tone in all modes.

I've never noticed it with any other aiming mode. Then again, every other mode gives you visual lock and launch authorization cues. There is none in this mode. Hence the auditory lock cue...that would be my guess.

...

 

Realistically you should get the audio tone in all modes.

Certainly makes sense that that would be the case.

So the R-27ET and R-73 when used by the Su-27 should provide the same sort of audio tone that the AIM-9 does with western aircraft, i.e. no matter what method of directing the seeker head to the target is used (radar, IRST etc) the seeker on the missile should provide an audio tone signifying that it has a valid lock?

No, not the same tone. Same idea, but not same tone. IIRC it's a 400hz tone in the flanker, or maybe a 900 one ... I don't recall.

But yes, you should hear a tone when the seeker believes it has a lock on something (what it has a lock on, that's a mystery to you mostly, in RL ... could be a flare, could be the sun :) )

IRST?

Infra Red Scanning & Tracking system.

hmmmm ... i never heard a tone on R-73 or R-27ET like an AIM-9

may be i use the radar instead of eos ...

in most cases i use the r-73 with vertical scan and i guess this mode uses the eos by default ... such in this case i never heard this tone ...

hmmmm ... i never heard a tone on R-73 or R-27ET like an AIM-9

 

may be i use the radar instead of eos ...

in most cases i use the r-73 with vertical scan and i guess this mode uses the eos by default ... such in this case i never heard this tone ...

In the sim, you'll only hear a tone in Fi0. No other mode has it.

Infra Red Scanning & Tracking system.

If that was meant for me, thank you. My question, though, was what part of the conversation his reply of "IRST?" was actually referring to.

Rich

No, not the same tone. Same idea, but not same tone. IIRC it's a 400hz tone in the flanker, or maybe a 900 one ... I don't recall.

Is this signal somehow modulated, or possibly derived from seeker signal, to allow pilot to estimate "quality" of the lock?

thx Ironhand :thumbup:

AFAIK not modulated, but it does have to do with the seeker signal. You'd get a steady tone which would indicate that the missile seeker 'audio' has exceeded a certain threshold. Again AFAIK/IIRC.

Is this signal somehow modulated, or possibly derived from seeker signal, to allow pilot to estimate "quality" of the lock?

It would have been nice to have the missile also able to launch with a radar Lock (or even tws lock) without having an ir lock. The missile could get updates from the aircraft until its own seeker has a stable lock. Then you could fire it without a stable ir signal from long range without getting the missile fire warning on the enemy aircraft's rwr. But I guess the missile is not capabele of getting in flight updates from the launching aircraft.

Though I must say that I can usually get an ir lock from quite a long range anyway.