# Smart bombs and the Dragon's Jaw
**URL:** https://boards.straightdope.com/t/smart-bombs-and-the-dragons-jaw/293031
**Category:** Factual Questions
**Created:** [March 5, 2005, 4:12am UTC](https://boards.straightdope.com/t/smart-bombs-and-the-dragons-jaw/293031 "2005-03-05T04:12:52Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)
#### Post date: [March 5, 2005, 4:12am UTC](https://boards.straightdope.com/t/smart-bombs-and-the-dragons-jaw/293031/1 "2005-03-05T04:12:52Z")
Watching the History Channel a program about smart munitions.
The Dragon’s Jaw was a bridge destroyed by laser guided bombs in Vietnam.
Four aircraft lased the target and four others dropped laser guided bombs, with four hits.
Did each bomb seek a specific laser? How did it “know” which to hit?
Why can’t a single aircraft lase the target and drop the bomb?
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### Author:  [@Helix](https://boards.straightdope.com/u/Helix)
#### Post date: [March 5, 2005, 9:27am UTC](https://boards.straightdope.com/t/smart-bombs-and-the-dragons-jaw/293031/2 "2005-03-05T09:27:52Z")
Just a couple of WAGs.
There had been numerous attempts to take out the bridge and they wanted to make sure the target was sufficiently lit to better ensure sucess. Poor weather was often an issue over North Vietnam and maybe that affected their ability to reliably lase the target.
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### Author:  [@Ninja\_Pizza\_Guy](https://boards.straightdope.com/u/Ninja_Pizza_Guy)
#### Post date: [March 5, 2005, 2:29pm UTC](https://boards.straightdope.com/t/smart-bombs-and-the-dragons-jaw/293031/3 "2005-03-05T14:29:21Z")
Woohoo! Finally, a chance to show off my USAF geekery. I worked on laser guidance systems when I was in, and I remember being told about this raid or one like it in tech school.
1: How the bombs “know” which laser to follow: The laser pulses in a given pattern; the pattern is different from aircraft to aircraft and from day to day, unless you want more than one plane’s worth of bombs to hit the same target. Say plane 1 is running 10 pulses per second, each pulse lasting, say, 25 nanoseconds. The bombs for that plane are set to look for that pulse and only that pulse. Plane 2 is running 12 pps at 15 nanoseconds/pulse. Its bombs will only look for **that** pulse. Continue for the other planes.
2: Why four planes? IIRC, this was the first time the system had ever been tried in an actual combat situtation and they didn’t know how well it’d work.
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### Author:  [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)
#### Post date: [March 5, 2005, 2:39pm UTC](https://boards.straightdope.com/t/smart-bombs-and-the-dragons-jaw/293031/4 "2005-03-05T14:39:39Z")
Why does one guy lase the target and another drop the bomb? One lases it from further away while the other guy gets shot at dropping the bomb and leaves?
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### Author:  [@Ninja\_Pizza\_Guy](https://boards.straightdope.com/u/Ninja_Pizza_Guy)
#### Post date: [March 5, 2005, 3:16pm UTC](https://boards.straightdope.com/t/smart-bombs-and-the-dragons-jaw/293031/5 "2005-03-05T15:16:12Z")
Moving more into WAG territory, but it might depend on which delivery method they use. I forget the names, but there’s one delivery profile where you fly straight over the target & drop the bombs, and another where you fly toward the target, then as soon as you release the bomb you turn sharply back toward the way you came.
Nowdays, the systems can keep the target centered even during the more radical maneuvers, but the earlier systems might have had problems holding a target lock. If that was the case, the designating aircraft would have been further back, holding the laser on target while the bombing aircraft would have delivered the bomb closer to the target, where it would have ridden the laser reflection down.