High-Altitude Torpedo Launch

Something I've often seen claimed (and seen depicted in Hollyweird
epics) but never confirmed by someone in a postion to know, was
whether or not a really noisy aircraft (like a P-3 or a HS-3) could
actually be detected by a sub's passive arrays. I've always had my
doubts (that air/water interface is tough to penetrate) but I really
don't know.

Bill, I had a 5 day trip on the USS Boston as a 'field trip' to answer
that question for our staff - even at a fairly good SOA, the crew of
the SSN could plot and avoid sonobuoy splashdowns, to the point that
they aimed their boat between passive buoys or steered completely
around them. The sonargirls could also hear each 'mark on top',
whether it was a fixed wing or helo, but I didn't hear them call S-3
passes and I gathered they were harder to detect. There was no problem
at all hearing the H-3, and it showed up on their sonar displays so it
wasn't just a matter of "Sparks" squeezing his headphones together and
yelling, "Cap'n! We got company!" A helo in a dip was easy to hear -
at least as easy as surface craft. I never felt comfortable in a dip
after that excursion.

When you were VS, were you in Stoofs? If so, I'd love to hear how
'sniffer' worked.

v/r
Gordon

On 15 Jun 2006 10:24:43 -0700, "Gordon" wrote:

Bill, I had a 5 day trip on the USS Boston as a 'field trip' to answer
that question for our staff - even at a fairly good SOA, the crew of
the SSN could plot and avoid sonobuoy splashdowns, to the point that
they aimed their boat between passive buoys or steered completely
around them.

Interesting. Was this at all sea-state dependant? Did a choppy
surface make it tougher?

The sonargirls could also hear each 'mark on top',
whether it was a fixed wing or helo, but I didn't hear them call S-3
passes and I gathered they were harder to detect.

Big props flailing the air do create vibrations! ;-)

There was no problem
at all hearing the H-3, and it showed up on their sonar displays so it
wasn't just a matter of "Sparks" squeezing his headphones together and
yelling, "Cap'n! We got company!" A helo in a dip was easy to hear -
at least as easy as surface craft. I never felt comfortable in a dip
after that excursion.

I'm not so surprised about a helo. I am surprised about a standard
sonobouy. Of course when helo lights-off it's got to be pretty
noticeable!!!!!!!!! :-)

When you were VS, were you in Stoofs?

Ayup.

If so, I'd love to hear how
'sniffer' worked.

Well, to get the "real" scoop on how Sniffer works you'd have to ask
Julie!!!!!!!!!!!!!!

From my trusty NATOPS the AN/ASR-3 detected particulate matter from
diesel exhaust. It took in an air sample, analyzed it (I don't
remember how), and gave a visual and aural indication. It could be
set for sensitivity. It would give an "in trail" and "out of trail"
mark that the crew would plot, then reverse course to re-enter the
trail gaining additional "marks." Eventually you had a rough course
for the target.

Not only would it detect a snorting pig boat, it would also detect
destroyers, merchant ships, fishing boats, and the entire East Coast
of the U.S.!!!!! In other words, whatever value it had in open ocean
conditions was quickly lost as you approached crowded waters or
polution filled urban areas.

Of course, if the sub can hear a 'bouy splashing down that gives the
aircraft a deception opportunity by "shotgunning" an area with a
'bouys and decoys. That could be an effective tactic in some
circumstances.

Bill Kambic
Haras Lucero, Kingston, TN
Mangalarga Marchador: Uma Raça, Uma Paixão

In article ,
wrote:


Bill, I had a 5 day trip on the USS Boston as a 'field trip' to answer
that question for our staff - even at a fairly good SOA, the crew of
the SSN could plot and avoid sonobuoy splashdowns, to the point that
they aimed their boat between passive buoys or steered completely
around them.

Interesting. Was this at all sea-state dependant? Did a choppy
surface make it tougher?

The sonargirls could also hear each 'mark on top',
whether it was a fixed wing or helo, but I didn't hear them call S-3
passes and I gathered they were harder to detect.

Big props flailing the air do create vibrations! ;-)

There was no problem
at all hearing the H-3, and it showed up on their sonar displays so it
wasn't just a matter of "Sparks" squeezing his headphones together and
yelling, "Cap'n! We got company!" A helo in a dip was easy to hear -
at least as easy as surface craft. I never felt comfortable in a dip
after that excursion.

I'm not so surprised about a helo. I am surprised about a standard
sonobouy.

I can vouch for Gordon's experiences, as I have heard to buoy splashes
listening to acoustical tapes from subs.



Of course, if the sub can hear a 'bouy splashing down that gives the
aircraft a deception opportunity by "shotgunning" an area with a
'bouys and decoys. That could be an effective tactic in some
circumstances.


Yes, them hearing a buoy splash is helpful to them but not necessarily a
pass from destruction. They can't be sure of the splashes they may nhot
have heard...and when the helo goes into dip, the crew in the helo
already knows the sub knows we're there. At that point, we do not so
much care. They can run all they like, but two or more leap-frogging
helos with active sonar (and a good crew of AW's) will very likely be
some of the last sounds they hear (next to the torps).



--Mike

wrote:


Well, to get the "real" scoop on how Sniffer works you'd have to ask
Julie!!!!!!!!!!!!!!


Except that -she- wouldn't 'kiss and tell'


From my trusty NATOPS the AN/ASR-3 detected particulate matter from
diesel exhaust. It took in an air sample, analyzed it (I don't
remember how), and gave a visual and aural indication. It could be
set for sensitivity. It would give an "in trail" and "out of trail"
mark that the crew would plot, then reverse course to re-enter the
trail gaining additional "marks." Eventually you had a rough course
for the target.

Not only would it detect a snorting pig boat, it would also detect
destroyers, merchant ships, fishing boats, and the entire East Coast
of the U.S.!!!!! In other words, whatever value it had in open ocean
conditions was quickly lost as you approached crowded waters or
polution filled urban areas.

Of course, if the sub can hear a 'bouy splashing down that gives the
aircraft a deception opportunity by "shotgunning" an area with a
'bouys and decoys. That could be an effective tactic in some
circumstances.


Yes, I remember those, we didn't use it much, pretty imprecise as
you indicate...perhaps it worked sort of like a household smoke
detector?...we used to call it "Ash in" and "Ash out" as the
detector gained and lost the 'scent'...
--

-Gord.
(use gordon in email)