Kh-25 premature detonations and other notes

[Speed]

In the course of building my next mission which will be naval based, I have been doing alot of testing with the Ka-50 and the Kh-25. I have figured out many of the Kh-25 mechanics, and I will note them below. However, I have not been able to figure out ANY correlation between what I am doing and premature detonations of the Kh-25 missile. About 33% of the time when you fire it, it will just explode about 500 meters in front of your face for no apparent reason. If you ripple fire two of them, if one explodes they will usually both explode (possibly the blast of one destroys the other?). On the other hand, if you fire them single, about 1 second apart, at least one missile will almost always make it. So anybody have ANY CLUE what causes the premature Kh-25 detonations?!?!

 

I would like anyone who has experience with this missile to comment on my findings below. I plan to put this, or something like this, into a mission briefing so I just need to check the accuracy.

 

Kh-25 mechanics: Missile can be guided in either normal or standby (designator) laser modes! If fired in normal mode, but sure to wait till there is NO COUNTDOWN for the laser on the HUD in the lower left corner.

 

Procedure in normal laser mode:

1) lock up target and get laser range. When LRF fires, you will notice the missile reticle jump to your target (because the missile seeker head sees your laser beam)

2) When the countdown in the lower left corner dissappears, FIRE! The HUD will display a countdown timer in the lower left corner again, this is how long the laser is firing for. It will typically be like 45 seconds. I haven't tested it yet, but other people in the area who have Kh-25s pointed at your target should see their missiles' reticles jump to your target and should be able to also guide their missiles on your laser spot.

 

Procedure for standby (designator) mode (my prefered mode, it avoids any issues with incorrect lase times that the weapons system might plague you with):

1) First, lock the target and get range in NORMAL laser mode (to avoid excessive lasing time that can burn you out).

2) Switch laser to standby mode. Press the target designate button to start lasing. You will see the missile reticle "jump" to your target. Additionally, a countdown time appears in the bottom left corner of the HUD telling you how much longer your laser is on (typically about a minute). Anyone else who is in the area and has Kh-25s pointed at your target will also see their missile reticles "jump" to the target, and will be able to guide their missiles on your laser spot.

3) Fire!

 

Notes:

The Kh-25 has VERY poor maneuverability and flies a pure pursuit course, so if you're engaging a ship moving more than about 30kmh perpendicular to you, you may need to aim at the bow of the ship to ensure a hit.

 

Due to premature detonation, fire the Kh-25 in singles about 1 second apart. Make sure you put the system in manual first, or else it may disallow firing the missile. If very low to the water or ground, ensure that the nose of the aircraft is at at least 3-5 degrees up (about the normal hover position) or else your missile may hit the terrain in front of you.

Edited August 24, 2010 by Speed

[power5]

Am I missing something? How are you flying a Kh-25?

 

Don't drink and post. This is a vihkr, not a chopper. Duh. Not sure what I was thinking.

Edited August 25, 2010 by power5

[CAT_101st]

Normal mode is not to be used with the KH 25ML. Second meathod good. But keep in mind only the first 20 seconds are for lasing with a 40 second cool down.

A cool thing that you can doo with the KH 25ML to extend its range is in multy player you can have a wing man lase for you and whin his laser stops you turn your on. This will extend your range out to 15K well out side of some sam's range. Or you can sneak up to 9K to target have a buddy at 15K and lase for you. Popup fire and then hide.

[Speed]

Normal mode is not to be used with the KH 25ML.

I had assumed that they did not work in normal mode, but today when testing it I had a missile guide all the way to impact in normal mode. And yes I have a track to prove it. First set of missiles fired were intended to be verification that the Kh-25 does not work in normal mode, but instead I got the OPPOSITE result. Second and third sets of missiles were to verify that the missile wouldn't guide if I fired it in normal mode while the countdown timer was still active. I picked a target with not enough angular velocity for the first set of missiles, which is why I performed the experiment twice. After that, I spent some time trying to duplicate the occasional blackshark key input lockup error I get with no success.

 

Just now, however, I tried to hit targets in normal laser mode with the Kh-25 and the laser wouldn't stay on long enough to hit a mover. So I am very confused. Why did my Kh-25 work in normal mode earlier and not now?!

 

Second meathod good. But keep in mind only the first 20 seconds are for lasing with a 40 second cool down.

 

Thank you, I just tested it (by not firing a missile and just watching the missile reticle for when it returned to center) and you're right, it looks to be the first 22-24 seconds or so! This can definately explain some "odd" missile tracking behavior I noticed!

 

A cool thing that you can doo with the KH 25ML to extend its range is in multy player you can have a wing man lase for you and whin his laser stops you turn your on.

 

Cool, thanks for the tip!

[BaD CrC]

Wow, didn't know you can use the laser guidance of the wingman for your missile. This is a great tip and definitively a great sim!!

[Speed]

Wow, didn't know you can use the laser guidance of the wingman for your missile. This is a great tip and definitively a great sim!!

 

It doesn't work at all for Vikhrs though, even when you set it up so your missile should find your wingman's beam. I hovered DIRECTLY over someone who had their laser in designator mode. As soon as he announced he was lasing, I fired my Vikhr, and it fell right through their beam and did not try to align itself with it. Does the laser designator/range finder have a different beam shape or code in laser designator mode as opposed to normal that would keep a Vikhr from guiding, or is this simply not something the devs ever thought would be worth modelling?

[159th_Viper]

.....Does the laser designator/range finder have a different beam shape or code in laser designator mode as opposed to normal that would keep a Vikhr from guiding, or is this simply not something the devs ever thought would be worth modelling?

 

Yes.

 

Two different laser energy needed; 25ML easily detected by LWR/A vikhr almost impossible to detect via LWR:

 

The beam-rider (vikhr) is essentially riding within a 'funnel' of laser energy surrounding the missile all the way to target. Vikhr then attempts to stay/aligh itself within this 'funnel' of laser energy by means of servo's in the missile tail, hence the distinctive spiral trajectory.

 

The 25ML on the other hand homes in on the reflected laaser energy from the target you are painting with your laser.

[Speed]

Yes.

 

Two different laser energy needed; 25ML easily detected by LWR/A vikhr almost impossible to detect via LWR:

 

The beam-rider (vikhr) is essentially riding within a 'funnel' of laser energy surrounding the missile all the way to target. Vikhr then attempts to stay/aligh itself within this 'funnel' of laser energy by means of servo's in the missile tail, hence the distinctive spiral trajectory.

 

The 25ML on the other hand homes in on the reflected laaser energy from the target you are painting with your laser.

 

Yes, I am aware of the difference between a beam rider and a SALH, but my question is whether the beam shape is any different while in normal vs. laser designator modes. I guess I could try guiding a Vikhr in standby mode, but that doesn't answer the question IRL.

 

I didn't think that they might adjust output power as well. Is that properly modelled in the game in terms of your laser burning out sooner or later?

Edited August 25, 2010 by Speed

[GGTharos]

To add more detail to Viper's explanation, the Vikhr's sensors are in the tail - they are looking back towards your helicopter specifically and they sense the grid projected by the guidance laser; the Vikhr then attempts to steer such that it does not exit the grid (probably as close to center as possible, AFAIK).

[GGTharos]

It is different. SAL just 'spotlights' the target with a laser dot of whatever size, possibly pulsed (with code), while the guidance laser for the vikhr is much weaker and its purpose is to project a grid.

 

Yes, I am well aware of the difference between a beam rider and a SALH, but my question is whether the beam shape is any different while in normal vs. laser designator modes. You say the laser output power is less in normal (Vikhr guidance) mode? I guess I could try guiding a Vikhr in standby mode, but that doesn't answer the question IRL.

[Kenan]

Don't worry Speed. We all had at one point in time, problems with premature missile detonations. It's quite normal, nothing to worry about.

[4c Hajduk Veljko]

Don't worry Speed. We all had at one point in time, problems with premature missile detonations. It's quite normal, nothing to worry about.

Ha, ha, ha ... This reminds me of the Jeff Dunham's "Ahmed the dead terrorist". Ahmed too, had a problem with premature detonation! :)

 

http://www.youtube.com/watch?v=1uwOL4rB-go

[Speed]

Don't worry Speed. We all had at one point in time, problems with premature missile detonations. It's quite normal, nothing to worry about.

 

Yea, but these are blowing before they even penetrate their targets. Quite a way to ruin the "sortie".

[CAT_101st]

Hay speed I know a few guys in your neck of the woods that fly BS. and FC2

[Speed]

Well, since no one has any clue why the Kh-25 prematurely detonates, I guess we can call it a bug in the game?

[159th_Viper]

Well, since no one has any clue why the Kh-25 prematurely detonates, I guess we can call it a bug in the game?

 

I assume this is readily reproducable on a clean, unmodded and correctly-patched install?

[CAT_101st]

Speed the only time I have the KH-25ml explode is if I lose a lock, turn off target to far, use the wrong mode, here is a big one ti gets shot down wile in flight to target (2s6,ships exc. exc.) If attacking a ship launch two at a time like you discribed befor, launching 1 at a time.

[Udat]

Yea, but these are blowing before they even penetrate their targets. Quite a way to ruin the "sortie".

That's what she said!

[Speed]

Ok, for some reason, the Kh-25's are only very rarely exploding right off the rail anymore. Donno what or why, but now that I am firing them single, with just a second or two of spacing, they seem to be doing better.

 

HOWEVER

A game-breaking bug has cropped up, at least for the mission I have slaved so hard over. It seems that Kh-25s have a very difficult time guiding from low altitude. Just to show you guys I am doing everything right, here is the procedure I am using:

 

Lock up target with shkval, laser in normal mode.

 

When about 10km away, I will switch the laser to standby.

 

Weapons system in manual, I will then press the target designate (enter on the keyboard) to start firing the laser. A countdown timer appears on the hud, typically between 35 and 60 seconds. As soon as the countdown timer appears, I will see the missile reticle jump to the target, and then I will fire.

 

From higher altitude, it seems this works a very large percentage of the time. When one goes external, they can watch the missile slowly tracking the MOVING target and laser beam.

 

HOWEVER, the success rate at an altitude of <10m seems to be quite dismal, perhaps 50% or less. What happens is quite often, the missile just does not track the moving laser beam, period. The missile will hit the spot that the target was at when the missile was fired. Other times, even more odd behavior is noticed. For instance, some times the missile will track the beam, then stop tracking it, then start tracking it again, then stop, etc, etc during the missile's flight, usually resulting (in this case) in a miss.

 

I have some theories. The shkval and laser sometimes do extremely odd things that seem to certainly be bugs. For instance, you ever been at low altitude, with no obstructions between you and a target, and lased something and had it read like 7km when you know it's more like 14km? You ever had a target locked, like 8km, and the range to the target just starts dropping rapidly out of the blue till the range reads like 0.1km? Not all of these weird things can be attributed to laser problems (because in the second case, the laser is not firing), but certainly some can. I think that even over flat terrain, the game sometimes erroreously detects an obstacle between you and your target that gives a false range value. This is especially prevalent at low altitude or while aiming near the horizon.

 

A possible solution, especially against ships, is to lase targets from as high of alitude as possible (perhaps 11 or 12 meters, any higher and you will get shot down). Additionally, aiming for a spot significantly above the waterline may help to reduce erroroneous laser returns if that is the problem. I will test this and let you guys know what I find.

 

Another possible work around is to have everyone present at the target area except the "primary" designator spam the laser in normal mode on the target being attacked. Kinda an off the wall idea, but who knows.

 

Yet another idea, kinda a variant on the above one, is to have an initial guider and terminal guider for the missile. One person fires the Kh-25 immediately after designating the target in NORMAL laser mode, so that the missile heads off in the correct direction of the target. For terminal guidance, another person (or the same one, even) fires the laser again about 10 secs before missile impact in standby mode.

 

By the way, additional incredibly odd bugs have been noticed during testing of the Kh-25 missile. Once, my laser DECOUPLED from my shkval. Yes, my laser began pointing (according to the Kh-25 reticle) in a direction at least 5 degrees different than the direction the skhval was pointed. I'm not sure of that one would reproduce on a track or not. Secondly, see the track already posted on this thread by me where a Kh-25 successfully guided on a moving target in NORMAL laser mode.

 

Anyway, if any of you guys have gone through struggles like this before with this weapon and have any ideas, I'd love to hear them.

 

Oh by the way, I do not have a track of this behavior because the tracks are too big to upload here. Maybe I will make a youtube vid of it when I get a chance.

Edited September 20, 2010 by Speed

[Speed]

A cool thing that you can doo with the KH 25ML to extend its range is in multy player you can have a wing man lase for you and whin his laser stops you turn your on. This will extend your range out to 15K well out side of some sam's range.

 

One of my squad mates and I tried this, and it did not work. The missile did not pick up the second laser beam on the moving target. Note that the missile will always hit the spot where the laser was when the missile was launched, or if it was actually tracking something, the spot where it lost the beam, so it will never have an issue with hitting a non-moving target. Are you sure the target you handed off to another laser beam was moving?

[GGTharos]

So you're salvoing missiles simultaneously and they're blowing each other up. It shouldn't happen every time, but game quirks aside, that is definitely a realistic possibility.

 

As for launching missiles at super-low altitude, the expectation that they should work when you do this should be pretty much zero, N/A most games. Only a certain class of aircraft carry stores that can be used from that low, and they're usually the type that beat the air into submission instead of real um ... flying.

 

Anything that comes off a jet needs to lose altitude usually for the rocket motor to fire and the launch to be successful etc etc. While I realize that it is fun for you to attack ships with the frog, realize that realistically speaking, you're being given a bit of artificial help, and you'd be getting shot at from 15km away by any ship with serious air defense capability, at any altitude.

[Speed]

So you're salvoing missiles simultaneously and they're blowing each other up. It shouldn't happen every time, but game quirks aside, that is definitely a realistic possibility.

 

As for launching missiles at super-low altitude, the expectation that they should work when you do this should be pretty much zero, N/A most games. Only a certain class of aircraft carry stores that can be used from that low, and they're usually the type that beat the air into submission instead of real um ... flying.

 

Anything that comes off a jet needs to lose altitude usually for the rocket motor to fire and the launch to be successful etc etc. While I realize that it is fun for you to attack ships with the frog, realize that realistically speaking, you're being given a bit of artificial help, and you'd be getting shot at from 15km away by any ship with serious air defense capability, at any altitude.

 

I'm not flying the Frog, I'm flying the Ka-50. And yes, I realize that it is not realistic to be able to attack ships such as a Kirov, Slava, or a Neustrashimy with a helicopter, but "not being realistic" is not an excuse for buggy weapon behavior. I am not saying that ED make some huge mistake here- they DID NOT. I understand that the Kh-25 is kind of an "easter egg", so I am not saying there should be a strong expectation that it should be modeled perfectly. I'm just saying, the fact that they did not model the doppler returns of the spinning rotors and did not model ships being able to engage helos at very low altitude allowing you to get unrealistically close enough to fire the Kh-25 is not an excuse for the Kh-25 not working correctly.

Edited September 20, 2010 by Speed

[GGTharos]

Actually you're right. The bug is that they work in those conditions I guess. ;)

[Speed]

Actually you're right. The bug is that they work in those conditions I guess. ;)

 

I said nothing of the sort. It's not a bug that ships do not engage you down very low, that's a game mechanics working as intended, it's just that it happens to be unrealistic.

 

Does the Kh-25 have some actual limitation IRL that keeps it from being fired down low?

 

And that is all VERY beside the point. The point is, the Kh-25 does not properly track a moving laser spot a significant fraction of the time.

 

I've seen these things not track targets after being launched at high altitude too, but it's not as common. Tonight or tomorrow, I will try to come up with a track that shows all this. Alternatively, I could just capture portions of tracks and post them to youtube.

Edited September 21, 2010 by Speed

[Speed]

Here's the latest Kh-25 WTF moment. The mission is a testing version of a mission I am building, with unlimited ammo on so that Kh-25 mechanics can be tested. Note in the track how the seeker head for the Kh-25 becomes completely uncontrollable and keeps slowly drifing to the right. Even after resetting the weapons system, the Kh-25 seeker kept jumping back to a spot where it thought it was seeing laser energy- even after telling the other guy in the mission to go back to spectators, the Kh-25 seeker head kept seeing the phantom laser spot. Note that this a bug I HAVE seen before, and it is not dependent on altitude. Also note, I had to delete the previous track posted in this thread to make room for this one :(