Small diameter bomb and a motor?
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I love the small diameter bomb. Ever since I read about it a few years ago I couldn’t wait to blow stuff up with it in BMS. And now it is here. So this weekend I finally had some time to check out 4.33 and headed out to KOTAR about twenty times in a quick TE I made and blew stuff up. One weapon I used quite a bit was the SDB. It is simple and easy enough to use.
However… on several flights I noticed something strange… After I dropped each one they’d magically fly from beneath me into an arc in front of my jet. That did not seem right as per the BMS manual,
SDB is an unpowered, glide weapon that has deployable wings and is guided by a self-contained INS/GPS set.
So I went to weapon cam after dropping them and I heard an engine sound that seemed to be accelerating them up to about 660 knots every single time I dropped one before it cut off and they flew to their target. If they are unpowered weapons, they should never pass my jet unless I cut throttle. If I maintain constant heading and velocity, the SDBs should fall behind me over time due to drag.
Is this a bug or a feature? A quick search through various literature and websites gave me the same conclusion–they aren’t powered weapons unless it is the ground launch variant which has a rocket motor. The aircraft mounted one has no motor. But it seems the ones in BMS do?
edit, video evidence:
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From what I can tell all of the IAMs do this, not just the SDBs.
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It’s not supposed to…
#----------------------------------------------------- # Engine #----------------------------------------------------- engLocation 0.00 0.00 0.00 EngineSound 0 hasGasDynamicManeuvering 0 mistrail 0 contrail 0 misengGlowBSP 0
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In BMS, JSOWs and SDBs are defined as missile without propulsion. So I have no idea why you heard a motor sound (other than the one of your AC, obviously).
There is a slight problem of missile ejection velocity but that shouldnt make the bomb fly an arc accross your hud.
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SDBs are getting “pushed” a bit forward yes, but it’s not like they get to higher speed than the jet, if you keep flying straight you will see that you are far faster than them. It’s more like they get a 1-time boost but for sure it’s not any motor power that keeps them going, you can try and see that dropping them at low altitude will cause them to fall very short
I wanted to check why they are being pushed like that but never got to it really, I guess it’s related to their special ejection (the roll that they do), I’ll check that stuff in sometime.
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Alright, I made a video showing it happening. They definitely accelerate to around 640 - 650 knots, regardless of whatever speed my jet is flying.
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@Mr_Blastman:
Alright, I made a video showing it happening. They definitely accelerate to around 640 - 650 knots, regardless of whatever speed my jet is flying.
Confirmed, and I know why… some thrust has been added to the FM of the SDB. Good catch !
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Yes, for JDAM this is known and actually it’s a different story… JDAMs are managed by bombs code which basically has no FM like missiles have, so it’s a huge compromise because JDAM is actually more like a terrible glider than a bomb. JDAMs were always “kicked”, if you ever seen that in 4.32 it was WAY worse because they could have kicked much faster, so I tried to slow them down, release is smooth but still there is the compromise because of no real FM to make them glide… so this is where we are. That’s I guess the best we could get them without turning them into a missiles objects, maybe in the future.
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Maybe it’s a case of how they are being “kicked”…slightly forward vice always perpendicular to the rack? Could the release angle be getting into your math?
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Yes, for JDAM this is known and actually it’s a different story… JDAMs are managed by bombs code which basically has no FM like missiles have, so it’s a huge compromise because JDAM is actually more like a terrible glider than a bomb. JDAMs were always “kicked”, if you ever seen that in 4.32 it was WAY worse because they could have kicked much faster, so I tried to slow them down, release is smooth but still there is the compromise because of no real FM to make them glide… so this is where we are. That’s I guess the best we could get them without turning them into a missiles objects, maybe in the future.
In a world filled with too many defensive egos (as amply shown in the microcosm of many of this forum’s members), this kind of candid and frank honesty is much appreciated. Thanks.