TOW tracking realistic?

[Amaroq]

I just watched the SBpro TOW tracking vid and am a little disappointed, unless someone can set me straight. I have never fired a TOW from the Bradley, but I have fired a TOW from a swiss TOW Piranha and watched literally hundreds of others being fired from the same platform, so my question is this:

To the best of my knowlege, the all current versions of the TOW weapons system in service automatically keep the missile to the lower left of the point of aim until the terminal flight phase, when the missile draws up and in to strike the target. This is because the missile itself radiates a lot of heat and would obscure the target most of the way if it flew down your line of aim (you can't see anything for the first 5 or 10 seconds as it is already). Pretty much the only thing you do see of the missile is the red 'beacon' on the back that is part of the tracking system for the targeting device (it also has an invisible laser beacon).

Now, I gather the 'fireball' missile sprite we see in the vid is still just a placeholder, and obscured vision from the launch and the missile is still being worked on (I hope), but the flight path of the missile in the video is dead centre, which is AFAIK completely wrong. Paired with the missing obscuring from the launch and the missile, the whole TOW system simulation in SBpro appears to be still very, very rudimentary.

I say this for one because I was looking forward to having "my" weapons system in the game, but also because I know the Swiss military spent millions on simulators that could visually simulate the flight path and the obscured vision, because that was the most important factor in training gunners (one of the main problems with rookie TOW gunners is that they start watching the beacon 'dot' or subconsciously try to track the target the beacon instead of the crosshairs and subsequently lose the missile. The other major problem when firing 'live' for the first time is panic and abrupt steering inputs in those 7 seconds or so after launch when you can't see a thing).

So even just from a training point of view the TOW is pretty useless in its current state IMO, as the most essential problems and factors are not modelled. Unless the Bradley uses a totally different system, that is, but that would surprise me, since the flight path as I know it is dictated by the missiles extreme heat radiation after launch. You could't see a thing if it flew dead center.

Can someone clear me up regarding the bradley's TOW system and maybe someone from eSim let us know if there's any work on that planned?

[Sean]

The TOW model is indeed pretty rudimentary. There are a number of open issues to be worked on in the future, but I'm not sure when they are planning to tackle them. But for now, this is what we have.

[3Star]

all current versions of the TOW weapons system in service automatically keep the missile to the lower left of the point of aim until the terminal flight phase, when the missile draws up and in to strike the target

How does the missile know when the terminal phase should be? It has no internal rangefinder that I'm aware of.

NTM

[GaryOwen]

I just watched the SBpro TOW tracking vid and am a little disappointed, unless someone can set me straight. I have never fired a TOW from the Bradley, but I have fired a TOW from a swiss TOW Piranha and watched literally hundreds of others being fired from the same platform, so my question is this:

I spent a bit of time as a Bradley gunner and as a member of the test team I've seen the missile model and the Bradley fire control system model for SB Pro PE. As a Bradley gunner, however, because of their cost, I only ever fired a few live missiles. So, given your experience, I'll defer to your observations.

To the best of my knowlege, the all current versions of the TOW weapons system in service automatically keep the missile to the lower left of the point of aim until the terminal flight phase, when the missile draws up and in to strike the target. This is because the missile itself radiates a lot of heat and would obscure the target most of the way if it flew down your line of aim (you can't see anything for the first 5 or 10 seconds as it is already). Pretty much the only thing you do see of the missile is the red 'beacon' on the back that is part of the tracking system for the targeting device (it also has an invisible laser beacon).

So far as I remember, the TOW system does not have a mechanism for determining when the missile is in its 'terminal flight phase'. (I've never fired nor trained to fire the TOW-2B, which I understand does have a sensor in the missile to indicate when it should fire its plug down on to the target; that, however, is not the missile modelled.) In order to determine when the missile were to enter its terminal flight phase, there would need to be a range tracking system computing the range to target throughout the flight of the missile. Given the time length of the missile flight at max range, the target may have enough opportunity to change its distance enough to require updated information throughout the flight. I do not recall ever having to input range prior to firing a missile, nor do I recall ever being trained that such an input was taken into account by the MGS.

. . . [T]he whole TOW system simulation in SBpro appears to be still very, very rudimentary.

I concur that the missile flight model is not as polished as the ballistics model for tank main gun rounds. However, so far as the Bradley is concerned, the modelling is, I believe, at this point sufficient to require paying attention to pertinent tactical considerations in a manner that is at least one leap and a bound better than what we have in SB1.

Can someone clear me up regarding the bradley's TOW system and maybe someone from eSim let us know if there's any work on that planned?

I'm not speaking on behalf of eSim. But my hope as a member of this community, and as someone who really enjoyed gunning a Bradley more than almost anything else I've ever done, is that the model will one day in the not too distant future be as good as the model I trained with in the UCOFT. The SB community has enough people with real experience with the weapons systems that it models, that I think that my hope is a goal that will certainly be reached.

[GaryOwen]

Now that I've thought about it for a couple minutes, I recall that the missile flight motor fires once after launch and that the missile glides throughout its flight to the target. At least that's my understanding. The vents for the rocket motor exhaust are pointed away from the tail of the missile.

For an image of the rocket motor firing, see:
http://w4.pica.army.mil/Voice2005/050121/2005%2001%2021%20Voice%20online%20photos/2005%2001%2021%20ATGM%20firing%20TOW.jpg

Thus, at range, heat obscuration from the rocket motor shouldn't be much of a problem.

(Granted, that's a TOW-2B being fired from a Stryker, but it makes the point.)

[Rogue6g]

Nice vids!! From what I remember as a gunner on an M3A1/A2 , SB Pro PE seems pretty dead-on, although the thermals for the game don't seem quite as "distinct". Is there an option for redHOT/BlackHOT? As far as the initial Launch goes, yes there was quite a dust cloud, but it never affected my gunning because I used the Thermals when launching to be able to "see" through the dustcloud. From what I remember, the flight characteristics are pretty darn close to the TOW-2A except that the missile wobbled more the farther away from the target it was; the closer it got, the more "true" it flew. This could be from the rotary rockets on the sides of the missiles, which produce spin:the faster the missile spins, the "truer" or more stable the flight path.

One thing did get me laughing though. What BC would have the scouts dismount when the gunner fired that missile. The Backblast woulda knocked them on their ass. :oops:

[DrDevice]

After the video, I spent some time reading the FM for Bradley gunnery. (btw - the recticle appears to be an ODS version with the AA stadia lines, rather than the A2 version. Was this a mid-cycle upgrade, or just a design decision from eSim? Also, the ammo info does not appear beneath the recticle. Is that a List item?)

The FM says that the flight motor burns out in 1.5-1.6 seconds and between 280-320m downrange. The IR beacon is what communicates with the ISU, and so should not be disrupted by the missile itself. This is just FM stuff, and I've never fired one, but the "bottom left" issue isn't mentioned in the training. It just says keep it center mass and don't try to fly the missile.

[congo]

Primary function: Guided missile weapon system.
Manufacturer: Hughes (missiles); Hughes and Kollsman (night sights); Electro Design Mfg. (launchers)
Size:
TOW 2A Missile:
Diameter: 5.87 inches (14.91 cm)
Length: 50.40 inches (128.02 cm)
TOW 2B Missile:
Diameter: 5.8 inches (14.9 centimeters)
Length: 48.0 inches (121.9 centimeters)
Maximum effective range: 2.33 miles (3.75 kilometers)
Armor penetration: T-80 +
Time of flight to maximum effective range:
2A: 20 seconds
2B: 21 seconds
Weight:
Launcher w/TOW 2 Mods: 204.6 pounds (92.89 kilograms)
Missile Guidance Set: 52.8 pounds (23.97 kilograms)
TOW 2 Missile: 47.4 pounds (21.52 kilograms)
TOW 2A Missile: 49.9 pounds (22.65 kilograms)
TOW 2B Missile: 49.8 pounds (22.60 kilograms)
Introduction date: 1970
Unit Replacement Cost: $180,000

Mission: To engage and destroy enemy armored vehicles, primarily tanks. Secondary mission is to destroy other point targets such as non-armored vehicles, crew-served weapons and launchers.

Features: The basic TOW Weapon System was fielded in 1970. This system is designed to attack and defeat tanks and other armored vehicles. It is primarily used in antitank warfare, and is a command to line of sight, wire-guided weapon. The system will operate in all weather conditions and on the "dirty" battlefield. The TOW 2 launcher is the most recent launcher upgrade. It is compatible with all TOW missiles. The TOW 2 Weapon System is composed of a reusable launcher, a missile guidance set, and sight system. The system can be tripod mounted. However because it is heavy, it is generally employed from the HMMWV and LAV-AT. The missile has a 20-year maintenance-free storage life. All versions of the TOW missile can be fired from the current launcher.

Inventory: TOW launchers - 1247

Background: The original TOW missile had a diameter of 5 inches and a range of 3000 meters. Considerable improvements have been made to the missile since 1970. The Improved TOW (ITOW) was delivered in 1982. This missile has a 5-inch diameter warhead, and includes an extended probe for greater standoff and penetration. An enhanced flight motor was included in the ITOW, increasing the missile's range to 3750 meters. The TOW 2 series of improvements includes TOW 2 Hardware, TOW 2 Missile, TOW 2A Missile, and TOW 2B Missile. The TOW 2 Hardware improvements included a thermal beacon guidance system enabling the gunner to more easily track a target at night and numerous improvements to the Missile Guidance System (MGS). The TOW 2 Missile has a 6-inch diameter warhead and the extended probe first introduced with ITOW. The TOW 2B Missile incorporates new fly-over, shoot-down technology.

[congo]

http://www.fas.org/man/dod-101/sys/land/tow.htm

[SFViper19D]

I've fired 3 or 4 TOW-2B's. I don't recall them ever following the recticle LOS. I do remember them sort of porposing downrange until they reached the target and detonated. Never will forget the time one of the tracks down the line shot a dud and the second stage motor never kicked in. It just layed in the grass about 75m away looking like a dead shark. By the way, SOP dictated that all hatches be buttoned up. I wouldn't dream of firing one with dismounts on the ramp.

[GaryOwen]

Viper,

Do you remember which hatches have the safety switch that sets the hatch open warning lamp? IIRC, it's the driver's and the cargo hatches. Does the ramp have a safety switch that would set the warning lamp if it wasn't fully closed?

[Vati]

Heh, just wanted to post the same issue wrt TOW after watching the videos and I already see that I was not the only one who spotted the unreal behavior.

[TopKick]

If it works dont fix it.

[Storm91]

Viper,

Do you remember which hatches have the safety switch that sets the hatch open warning lamp? IIRC, it's the driver's and the cargo hatches. Does the ramp have a safety switch that would set the warning lamp if it wasn't fully closed?

If memory serves on the m2a1 it was all hatches with the exception of the troop door on the back of the ramp.Btw you can fly it somwhat just can't jerk it.Check this fired at a bmp that was moving right to left-then it disappered behind a 60ft barn.I went ahead and guessed- shifted the missle left steadily soon as she appeared on the other side boom.Tc was going no f%^&ing way!! :lol:

[1stADCavScout]

Viper,

Do you remember which hatches have the safety switch that sets the hatch open warning lamp? IIRC, it's the driver's and the cargo hatches. Does the ramp have a safety switch that would set the warning lamp if it wasn't fully closed?

I don't remember the vehicle caring about the status of the ramp at all. The safety feature with the driver and cargo hatches drove me nuts though. The driver pops the hatch a little bit to catch a smoke, you scan past 12 o'clock and wind up looking at the sky. :x

[Homer]

To the best of my knowlege, the all current versions of the TOW weapons system in service automatically keep the missile to the lower left of the point of aim until the terminal flight phase, when the missile draws up and in to strike the target. This is because the missile itself radiates a lot of heat and would obscure the target most of the way if it flew down your line of aim (you can't see anything for the first 5 or 10 seconds as it is already). Pretty much the only thing you do see of the missile is the red 'beacon' on the back that is part of the tracking system for the targeting device (it also has an invisible laser beacon).

So far as I remember, the TOW system does not have a mechanism for determining when the missile is in its 'terminal flight phase'. (I've never fired nor trained to fire the TOW-2B, which I understand does have a sensor in the missile to indicate when it should fire its plug down on to the target; that, however, is not the missile modelled.) In order to determine when the missile were to enter its terminal flight phase, there would need to be a range tracking system computing the range to target throughout the flight of the missile. Given the time length of the missile flight at max range, the target may have enough opportunity to change its distance enough to require updated information throughout the flight. I do not recall ever having to input range prior to firing a missile, nor do I recall ever being trained that such an input was taken into account by the MGS.

The TOW-2B is unique member of the family because it automatically flies about 6-7ft above the crosshairs and the warhead detonates when it senses that it is directly above the target by means of the target’s shape
and magnetic field.

As far as the MGS is concerned, range is irrelavant because all it cares about the missile's X/Y position relative to the LOS crosshair.

. . . [T]he whole TOW system simulation in SBpro appears to be still very, very rudimentary.

I concur that the missile flight model is not as polished as the ballistics model for tank main gun rounds. However, so far as the Bradley is concerned, the modelling is, I believe, at this point sufficient to require paying attention to pertinent tactical considerations in a manner that is at least one leap and a bound better than what we have in SB1.

Can someone clear me up regarding the bradley's TOW system and maybe someone from eSim let us know if there's any work on that planned?

I'm not speaking on behalf of eSim. But my hope as a member of this community, and as someone who really enjoyed gunning a Bradley more than almost anything else I've ever done, is that the model will one day in the not too distant future be as good as the model I trained with in the UCOFT. The SB community has enough people with real experience with the weapons systems that it models, that I think that my hope is a goal that will certainly be reached.

My nitpick is that it seems to work too fast.. there should be 1.5 sec delay (for squib and gyro spin up) from the time you pull the trigger to when the missile actually leaves the tube and another 1-2 secs for the missile to be armed, up to speed and fully manueverable.... but I'm not complaining too much because its better than what we got now.

[LancerVI]

I was also a Brad gunner and fired a couple of TOW's myself, not only on the brad, but on the dismounted launch system as well.

First, the tracking I saw in the video is pretty straight down the pipe. Not as realistic as you'd like to see, but it get's the job done. A wobble in it's flight doesn't really add much more in my opinion if you know that you don't "fly" the TOW to target. You have to ignore the Xenon Beacon. Just keep Crosshair on and it'll hit. When firing one live, the motor fires for a few milliseconds and then glides in. I don't remember it staying low left until impact, but just generally "floating around" the aim point until impact.

Also, on a brad, there is not much in the way of the sights being obscured, thermals or not. The TOW Hammer is relatively far left of the ISU, so I don't remember it being much of a problem. On the dismounted system, obscuration was obviously there, as the sights sit right on top of the tube.

Just my two cents.

Lancer VI

[3Star]

My nitpick is that it seems to work too fast.. there should be 1.5 sec delay (for squib and gyro spin up) from the time you pull the trigger to when the missile actually leaves the tube and another 1-2 secs for the missile to be armed, up to speed and fully manueverable.... but I'm not complaining too much because its better than what we got now.

The Beta team have already copped this one, and it's been listed in the bug/enhancement reporting tool for some time.

NTM

[Amaroq]

Now that I've thought about it for a couple minutes, I recall that the missile flight motor fires once after launch and that the missile glides throughout its flight to the target. At least that's my understanding. The vents for the rocket motor exhaust are pointed away from the tail of the missile.

For an image of the rocket motor firing, see:
http://w4.pica.army.mil/Voice2005/050121/2005%2001%2021%20Voice%20online%20photos/2005%2001%2021%20ATGM%20firing%20TOW.jpg

Thus, at range, heat obscuration from the rocket motor shouldn't be much of a problem.

(Granted, that's a TOW-2B being fired from a Stryker, but it makes the point.)

The TOW2 has two motors. The launch motor fires (or explodes, rather) the missile out of the tube, then the 'cruise' motor fires, after the fins have deployed. The launch motor fires straight back. The cruise motor is the 'sideways' firing one.

The heat development from just the launch was enough to blind you for several seconds, the fact that the missile was trailing this plume of hot air from the 'cruise' rockets would blurr the area around the missile. You weren't blinded in that phase, but you needed a pretty calm hand and a clear idea of where your target was. The firing I've done and observed was at 2500m above sea level though, and three quarters of it in winter, half of the time with snow, so the thermal impact had to be more severe than, say, Nevada. :) Good point that the launcher on the brad is more to the side. THe TOW-Piranha has the targeting sytems between the launchers, to the effect may be aggrevated by that.

Tracking the target was always done dead center of course, but the *missile* would fly to the lower left of the crosshairs. How it determined its terminal flight phase I don't know, either the targeting system has its own LRF or the missile just kept 2m to the lower left and the LOS-converngence made it look like it was drawing in. Regarding the flight path I'm beyond doubt, I've seen it too often and I've trained too many people to avoid those exact problems. :D It could be something custom made for the swiss military, but that would surprise me, frankly.

I concur with homer though on the delay. There's a gas canister that injects gas through a gyroscope to spin it up to several thousand RPM (20k, of the top of my hat), so when you pull the trigger there's a slight "pop" and a hiss while that happens (this again may only be audible due to the proximity of the lauchers to the gunner's head in the Piranha). Once the gyro has spun up it launches 'on it's own' with a very loud bang. :D

I thought I took a picture once through the commanders periscope with the crosshairs lined up with the gunner's, I'll see if I can find it, but I've 'lost' most of my old army stuff moving, so I haven't much hope...

[SFViper19D]

/agree about the delay. You heard a 'cathunk' when the trigger is pulled followed by a short pause. This has often been to the chagrine of many inexperienced crews who believe something is wrong and let go of the caddilacs thus terminating the missile once it leaves the tube.

As far as the hatches go I can't remember the ramp having anything more than the blackout circuit. The troop door had nothing along with the turret hatches. You can fire the TOW with the ramp down, I just wouldn't do it with the guys on the ramp....safety first you know.

Not that it bears any direct relation to this thread but I always hated being a safety/instructor on the AT-4 range. We had two guys with perforated eardrums from it.

[SFViper19D]

Also, I would have enjoyed seeing the TOW retired in favor of a dual Javelin launcher. Can't beat 'fire and forget' weapons especially when your faced with being immobile for 20-30 seconds while your missile is going downrange!

"Look at me! Look at me!" <waves arms emphatically at the enemy>

[ShotMagnet]

I believe the very latest version of the TOW is a FAF round. If true, that'd make for some interesting 'stick and move' engagements and Brads (or anything else mounting a TOW launcher) could become an echelon deadlier thereby.


Shot

[3Star]

I thought TOW-3 had been nixed?

Javelin needs a range increase before it can replace TOW.

NTM

[LancerVI]

I know I'm dreaming, but I always thought, as a Brad Gunner, it would be cool to see an AGM-114 Hellfire box installed instead of a TOW. I know they did it with a humvee, and I know it's a probably much to big, but it would be cool to see none the less.

http://www.designation-systems.net/dusrm/m-114.html
http://astronautix.com/lvs/hellfire.htm

Also, in this video, you can hear the gas charge spin up the gyro, short delay, then launch. (dismounted TOW) http://www.ansci.wisc.edu/sarge/delta/delta%20video/tow15.wmv

This is pretty cool....check this TOW video out:
http://www.raytheon.com/products/stellent/groups/public/documents/content/cms01_055824.wmv

and here is TOW wireless:
http://www.raytheon.com/products/stellent/groups/public/documents/content/cms01_055830.wmv

Raytheon cut the video here obviously....checkout how the clock jumps from 05 seconds to 23 seconds at 4200m. That's a long time to track!!!! No wonder the Army dumped it. How many tank rounds did my brad just take from the Tank and it's friends in that track.....jeeeesus, I shudder at the thought.

I truly don't recall the TOW staying low left in the retacle until hit. The only TOW that has a proximity type sensor is the TOW II B. Again, I just think it wobbled it's way down the pipe. I'm looking everywhere for in Sight video.

Merry Christmas all!!

Lancer VI

[stuart666]

I thought TOW-3 had been nixed?

Javelin needs a range increase before it can replace TOW.

NTM

Wasnt there discussion on Tanknet of a longer ranged version for the British army? It had already been proposed for the US army, but hadnt been picked up by them, presumably because they already have tow and Hellfire.

[DarkAngel]

Also, in this video, you can hear the gas charge spin up the gyro, short delay, then launch. (dismounted TOW) http://www.ansci.wisc.edu/sarge/delta/delta%20video/tow15.wmv

Thanks for that Lancer.

Now I'm one of these analytical types. I'm sitting pulling the movie file apart trying to work out the time sequence. Gary Owen and I have discussed this many times.

If the clunk hiss follows the trigger press then the trigger is pressed around 00:03.87 - 00:04.00

00:06.26-27 Missile leaves the tube (2.4 seconds after trigger press )

00:06:33 backblast from the "launch motor" is visible

Now what I'm trying to work out and hoping one of the Vets can help me with. Is it possible from audio queues only in this clip to work out when the flight motors kick in?.

[ShotMagnet]

Not an expert, but I play one on TV...

From what I've heard on the various clips I've heard, there's an impelling charge that kicks the missile from the tube. A second or two later the rocket motor ignites.

Again, going from what I've heard and seen, it sounds something like Pfisssshhhhh!-PAH-WHOOoossshhh!.

If you're to model the sound of a dud round (one where the rocket motor doesn't fire), it'd probably be just the first part (the Pfisssshhhhh!, followed a second or two later by a 'Thud!' when the missile hits the ground.

I remember seeing a bit of video where just that happened, during the run-up to ODS. A TOW-equipped HMMWV launched one as part of a live-fire exercise. The impelling charge blew the thing clear, the rocket failed to fire, and the missile flew maybe ten meters before coming down. The guys in the HMMWV weren't happy.


Shot

[Homer]

Now I'm one of these analytical types. I'm sitting pulling the movie file apart trying to work out the time sequence.

You need a better video player... here is what I got out of mine:

-1.5 sec
Gunner presses trigger; system sends prefire sequence to missile, starts chemical reaction in thermal batteries, blows explosive squib off nitrogen
bottle; gyroscope starts spinning.

0 sec
Gyroscope reaches 42,000+ rpm and disengages; sends electrical current to launch motor; launch motor fires.

+0.5 sec
Missile exits launch tube.

+0.8 sec
Wing 2 switch closes.

+.10 sec
Wing 4 switch closes; helium bottle opens; timed part of arming sequence starts; flight motor ignites.

+.145 sec
Delay switch changes state (part of arming sequence).

+.18 sec
Safety and arming unlock occurs. As missile accelerates to 19 Gs, the G force causes a rotor in the warhead to unlock.

+.53 sec
S&A clock mechanism rotates and aligns detonator with warhead. Missile is armed.

+1.6 sec
Flight motor burns out. Missile is fully armed and travelling at maximum velocity. It will coast the rest of the way on momentum and the lift from the four wings.

[GaryOwen]

Good to go Homer. You must have the DARPA version of Windows Media Player. But can your video player figure out how much momentum the missile will bleed off from flight corrections?

[Homer]

....But can your video player figure out how much momentum the missile will bleed off from flight corrections?

I cant find that button in the menu...

Are you asking about this from the perspective of the game or just a curious individual?

I think it can be safe to say that in terms of the end user, the effects are negligible because that has already been factored into the engagement envelope (except maybe at the extreme edges). This is mitigated by other factors such as the target sighting system and the physical limitations of the launcher assembly. This is applicable to both the game and the real world.

Regarding the real world, I messed with flight models before and probably can calculate a reasonable approximation of the missiles flight performance given time and motivation. BUT, one huge problem is obtaining the neccessary data to plug into the formulas because such information is either difficult to find or is classified by the military. Another problem is verifying the accuracy of the calculations. In real world, they just compare the theorical data with data gathered from the real thing... unless you have a private stash of TOW missiles and an instrumented test range for a backyard... I will bring the beer...

[GaryOwen]

Are you asking about this from the perspective of the game or just a curious individual?

Me? I'm just curious.

I think it can be safe to say that in terms of the end user, the effects are negligible because that has already been factored into the engagement envelope (except maybe at the extreme edges).

That is precisely about which I am curious. WTF is the engagement envelope for the TOW?

One huge problem is obtaining the neccessary data to plug into the formulas because such information is either difficult to find or is classified by the military.

If we have the weight of the missile, its velocity after the flight motor fires, its velocity at a couple points down range, and a rough guess at the size of the area of the control surfaces, is that enough to determine the engagement envelope and the missile's behavior within the envelope given certain gunner's inputs?

Another problem is verifying the accuracy of the calculations. In real world, they just compare the theorical data with data gathered from the real thing... unless you have a private stash of TOW missiles and an instrumented test range for a backyard... I will bring the beer...

I don't drink.

[Amaroq]

I'll go find my old manual in the cellar. There were a bunch of numbers, max. tracking speed etc. listed somewhere in there IIRC. Max range is 3700m because it runs out of guidance wire shortly after that. Weather and incoming fire is probably the more limiting factor than the missile's performance though.

Also, unlike, say, the dragon, the TOW only wobbles if the gunner does. If the gunner has a steady aim, the missile won't wobble a bit. It runs like on rails.

[LancerVI]

Runs on rails??? Only if there ain't any wind. The TOW wobbles all the way down the pipe. I've fired more than my fair share of em.

Lancer VI

[Homer]

If we have the weight of the missile, its velocity after the flight motor fires, its velocity at a couple points down range, and a rough guess at the size of the area of the control surfaces, is that enough to determine the engagement envelope and the missile's behavior within the envelope given certain gunner's inputs?

Even the simplest modelling will require more data than just what you got there. Just to get the basic aerodynamic characteristics (lift, drag, thrust and weight) is problematic...

For example, to calculate lift, you will need more than just the size of the fins, you also need information on its shape. Then you have to consider how it works mechanically: how much does it deflect in response to a control input (this affects lift and produces drag)? how often does it receive control inputs? etc... The missile body shape (which can be measured from pictures) will also generate some lift but you have to know how the angle of attack (which also affects the performance of the fin wings) as if flies downrange.

This just of the top of my head and I am sure there are other issue not listed that would need to be addressed. They call it rocket science for a reason.

I don't drink.

I forgot....
How about women? I know a couple of friendly ladies....

[GaryOwen]

Well Homer, rocket science ain't brain surgery.

Send the ladies over. They can clean up until I get home, then we'll do some heavy lifting.

[Amaroq]

Runs on rails??? Only if there ain't any wind. The TOW wobbles all the way down the pipe. I've fired more than my fair share of em.

Lancer VI
There were mostly excellent conditions when we fired :D : In a narrow mountain valley, so there was rarely much wind anyway, and the tech reps always wanted their little gadget (looked like a vacuum cleaner) hooked up to read some data off the targeting computer, so if things got too ugly they'd just stall until it cleared up or the rangemaster came to shut things down. :roll:

It does always 'wobble' a little, but IMO it's more a smooth oscillating, not really a wobble. Certainly nothing compared to the dragon, that - due to the steering system it uses - looks more like a rabbit on steroids than a ATGM. I meant "on rails" in a relative sense. We'll still see hollywood camera men laying tracks for while... ;)

[Grenny]

If we have the weight of the missile, its velocity after the flight motor fires, its velocity at a couple points down range, and a rough guess at the size of the area of the control surfaces, is that enough to determine the engagement envelope and the missile's behavior within the envelope given certain gunner's inputs?

Even the simplest modelling will require more data than just what you got there. Just to get the basic aerodynamic characteristics (lift, drag, thrust and weight) is problematic...

For example, to calculate lift, you will need more than just the size of the fins, you also need information on its shape. Then you have to consider how it works mechanically: how much does it deflect in response to a control input (this affects lift and produces drag)? how often does it receive control inputs? etc... The missile body shape (which can be measured from pictures) will also generate some lift but you have to know how the angle of attack (which also affects the performance of the fin wings) as if flies downrange.

This just of the top of my head and I am sure there are other issue not listed that would need to be addressed. They call it rocket science for a reason.



...I considered starting some calculations.
But it leads you to the beautiful world of hydrodynamics(well, as air behaves like a liquid most of the time...so i can use the same equations).
...I startet to panik after to lines, anyone elso who wants to try?
:roll:
But wait a minute....I could model a TOW in "fluent" (FVM-software) :twisted:
If I could convince my Prof to give me some calculation time :roll:

[LancerVI]

Runs on rails??? Only if there ain't any wind. The TOW wobbles all the way down the pipe. I've fired more than my fair share of em.

Lancer VI
There were mostly excellent conditions when we fired :D : In a narrow mountain valley, so there was rarely much wind anyway, and the tech reps always wanted their little gadget (looked like a vacuum cleaner) hooked up to read some data off the targeting computer, so if things got too ugly they'd just stall until it cleared up or the rangemaster came to shut things down. :roll:

It does always 'wobble' a little, but IMO it's more a smooth oscillating, not really a wobble. Certainly nothing compared to the dragon, that - due to the steering system it uses - looks more like a rabbit on steroids than a ATGM. I meant "on rails" in a relative sense. We'll still see hollywood camera men laying tracks for while... ;)

Wobble....yaaa.....I was just thinking about it...and you're probably right. Wobble is a poor choice of words. I guess I would say it "floats" around the aim point. I've never seen one go straight down the crosshair.

Lancer VI

[Amaroq]

That floating is the beauty of it. I was always amazed that the thing could glide at all on those stubby little wings, let alone glide that far.

That dead center vs. lower left thing intrigues me. I always thought that was something that came with the stock guidance system, but apparently not. I know the Swiss increased the shaped charge's performance in their TOW2A, but it's starting to look like they fooled around with the guidance system, too.

[flyboy]

I had to laugh when you wrote this..."There were mostly excellent conditions when we fired : In a narrow mountain valley, so there was rarely much wind anyway, and the tech reps always wanted their little gadget (looked like a vacuum cleaner) hooked up to read some data off the targeting computer, so if things got too ugly they'd just stall until it cleared up or the rangemaster came to shut things down".
Just imagine these guys in combat.When the weather gets nasty they get on the Tannoy""Ahem attention Terrorists...Due to adverse weather conditions we won,t be firing TOW,s at you today..Please be considerate and not drive any vehicles around today when we fight...Thank you and have a nice day!!!" :lol:

[Amaroq]

Live-fire excercises are always in better and more 'sterile' overall conditions that simulated shooting for safety reasons. A Dragon gunner was killed a few years ago when his missile malfunctioned and went vertical and lightning struck the guidance wire. The techies wanted to check the missile lots they let us use, so they wanted more or less usable results from a technical standpoint. The point of these live firings was to fire live, not simulate a real engagement as close as possible. That's what you have the laser sims for.

You could say the same about environmental and driving (max speed, 'roads') constraints on the ranges. That's just the way it is. You train with what you have. In a perfect world there's be no need to look out for someone else's property, ground water pollution or rare animals as you'er barrelling down the road or pumping highly noxious fluids and solids into the hills, but that's not the reality of things.

[flyboy]

Ouch thats gotta suck,getting struck by lightening on the guidence wire.Yeah I know you gotta protect the troops in training but they gotta remember,war and combat isn,t a game.My cousin got thrown from a jeep in Somalia a few years back.Wasn,t badly hurt but the potential is there.Hell I could have a Blackhawk crash on my house(touch wood) and flatten me.When it,s your time,it,s your time and nothings gonna stop it.

[Bjarne]

hello gentlemen,
I am new to this site, but a good friend,Johnny, told me it was time to drop in.
I have a little experince with TOW, but to be sure I dusted of the old tecnical manual.
the sequence for TOW, ITOW, TOW 2 and TOW 2A.
- 1,58s trigger
- 1,49s to - 1,10s gyro and alle the other electronic gadgets starts up. the MGS reads missile ID and Launcher type.
- 1,10s to -0.30s prefire jammer detection.
-0,01s fire signal and VTT interrupt enabled
0,00s missile first motion
0,04s missile launch motor burn out
0,047s missile clears tube
0,155s flight motor ignites(7 meter down range)
1,5s to 1,6s flight motor burns out (aprox 300m)max velocity (1074-1060 ft/s)
20,01s 3750 meter (velocity 390 ft/s)
I have only fired one myself, but seen a lot. ranging BGM-71A2 to BGM-71E. they are all different. Never head that it should be set up to track low left, but it kind of happens all the time as the missile falls through the crosshair before et gets a new stearing signal. the manual says nothing about this either.
I only have experince with the M113 and the landrover as platforms, but the MGS is the same. most nato countries in europe use the same 4 ech maintence facility.
as far as I know, it is the same MGS for the Bradly as well, except for units equipt with ITAS.(but my experince is kind of old '90-'96, moved on to tanks.)
I agree to little smoke and dust in the initial fase of the flight.
great site -- can I come here more often. :)
pardon my english, after all I am danish.
BJ

[foehammer]

Yeah I remember Johnny. He was on the Danish TV vid awhile back. Say hi to him for me.