AT15 sonic boom?

[Sublime]

Since AT15s go supersonic do they make a sonic boom on the ground? does that do anything besides break glass?

[Nidan1]

Good question, most audible sonic booms are created by aircraft flying at altitude. A high velocity bullet will make a cracking sound overhead if it passes near someone. (not a pleasant sound). I would guess that the trajectory of a Khrizantema is fairly flat, and the range is within a mile, so for anyone on the ground when one passes by it would probably give off a small boom when in supersonic flight. Probably would not even break glass.

Edited August 7, 2015 by Nidan1

[panzersaurkrautwerfer]

Size of the shockwave is proportional to the projectile breaking the barrier too.   A super-sonic missile will be loud, but it won't exactly be the same as if a fighter jet buzzed your house at super sonic speeds.  

[Sublime]

ah thanks. Because I remember going on base when it was the FRG in the 80s and the jets were loud then. But the only real close sonic boom Ive heard actually nearly knocked me off my feet my dad was a Lt Col at the time and the USAF liason to NATO at Norfolk and finagled us for a Navy families day ride out to sea on the Enterprise. You could walk all over the ship, they had A6s bomb dummy targets (this was like 95-96) but being the son of an officer I got to stand on the conning tower railing when an F14 buzzed the carrier going supersonic. I remember thinking odd the jets not making any noise then BOOOOOOM damn near knocked me over. Great experience. Very impressed with the carrier and everything. Awed by the Vulcan anti anti ship missile guns though we didnt get a demo as I remember hoping.

Edited August 8, 2015 by Sublime

[Sublime]

(not a pleasant sound.)

And a sound I know you heard quite a bit over there in the Nam. Im quite sure that was very very unpleasant. Since you.re here what do incoming mortars really sound like? Ive heard it described as almost an odd fluttering sound but i always had trouble visualizing that...?

[Nidan1]

Again sounds made by flying projectiles are more distinct when they are over your head. In Vietnam my experience with mortars was usually at fairly short range, especially during a night bombardment you could sometimes hear the shells leaving the tubes.

Unless the bombs were landing really close by you couldn't hear them in flight only the sound of the impact.

 

The favorite mortar of the NVA was the 82mm variety, pretty large, and when targeted really close to you they made a whooshing or whistling sound as they passed. It was always said that as long as you could hear them they weren't going to land right on top of you. When they landed, the explosion made a sound as if the air was being ripped apart, what was really loud was the sound of the fragments zipping through the air. VC and NVA usually had FOs directing fire during the day, so the mortar fire was often very accurate and scarey.

[Splinty]

We heard it a lot in Iraq too. The most common mortar the insurgents used was also the 82mm and as Nidan said if they were close enough you could hear the thump as they were launched and the boom as they impacted, but not in flight. Rockets on the other hand made a high pitched whistle, that I'll never forget. Fortunately for us (most of the time) Insurgent mortar teams operated in quantity not quality. Most attacks where I was (FOB Rustamiyah in Baghdad) were frequent, but not very accurate.

[Sublime]

Which is of course why in combat accounts you hear the phrase 'tubing!' a lot - the thumps of the mortar rounds leaving.  The rustling noise is anecdotal stuff Ive read from WW2.   That must make it even more terrifying you cant hear it in flight.  Is it a soldiers legend if you can hear it it wont get you? Because that sounds like wishful thinking...