I have read on numerous occasions that flight paths for the shuttle
have to be considerate of the double sonic booms it causes.

My questions:

What is a double sonic boom (other than two booms) and what causes
the double feature rather than the single boom?

Also, what damage on the ground will a sonic boom cause? Other than
a loud noise and window shaking. Will it damage building
foundations? Will it shatter windows?

Also, are all sonic booms the same or can they vary in intensity?
SOme louder than others. Some more intense. Some longer lasting.
Some covering a wider footprint.

TangoMan

Dear Tangoman:
I like the Concorde myself.
Sincerely,
Shaharaim Kumar
victoriatangoman wrote: I have read on numerous occasions that flight paths for the shuttle
have to be considerate of the double sonic booms it causes.

My questions:

What is a double sonic boom (other than two booms) and what causes
the double feature rather than the single boom?

Also, what damage on the ground will a sonic boom cause? Other than
a loud noise and window shaking. Will it damage building
foundations? Will it shatter windows?

Also, are all sonic booms the same or can they vary in intensity?
SOme louder than others. Some more intense. Some longer lasting.
Some covering a wider footprint.

TangoMan

>I have read on numerous occasions that flight paths for the shuttle
>have to be considerate of the double sonic booms it causes.
>
>My questions:
>
>What is a double sonic boom (other than two booms) and what causes
>the double feature rather than the single boom?
>
Most sonic booms are double booms. The double booms are created by the
front and rear of the vehicle.

>Also, what damage on the ground will a sonic boom cause? Other than
>a loud noise and window shaking. Will it damage building
>foundations? Will it shatter windows?
>
It can shatter windows, crack walls; foundations are unlikely but possible.

>Also, are all sonic booms the same or can they vary in intensity?
>SOme louder than others. Some more intense. Some longer lasting.
>Some covering a wider footprint.
>
Yes. Obviously the sonic booms amplitude is dependent on distance
(inverse square law).

Also the sonic boom is dependent on the size of the vehicle- Concorde
gives a much bigger boom than a military jet.

Also the shape of the vehicle, a sharp nose gives a much stronger boom
than a round nose.

There was an article about this in New Scientist.

> Message: 3
> Date: Tue, 03 Dec 2002 23:32:09 +0000
>
> >Also, what damage on the ground will a sonic boom cause? Other than
> >a loud noise and window shaking. Will it damage building
> >foundations? Will it shatter windows?
> >
> It can shatter windows, crack walls; foundations are unlikely but possible.
>

Right. It also depends on the local building codes.

In the third world where poor contruction methods are used, it could cause structural damage if the boom were close, not
sure about distance.

In California, buildings (since 1933) are designed to withstand small earthquakes, so would take most sonic booms with no
problem (except for the windows).

A much bigger problem than structural damage to buildings would be burst eardrums for humans.

Also, trauma of animals is a significant concern. Some animals can panic, injure themselves, and need to be destroyed.
For an expensive racehorse (or pedigree breeding bull), for example, this would be a significant financial liability (US$
millions per animal).

These are amongst the reasons the Concorde does not fly supersonic over land.

Sonics booms of the Space Shuttle occur at such high altitude there is no damage or injury potential. I heard them myself
several times when I lived in southern Calfornia.

How is this significant to space development ?

> These are amongst the reasons the Concorde does not fly supersonic
> over land.

If memory seves me correctly, there is a chef at the Osaka Hilton...

OOPS! Guess I've been watching too much Iron Chef. ;)

But really, I seem to recall reading somewhere that an oblique-wing
aircraft can get up to Mach 2.something-or-other before making a
sonic boom. In fact, I just stuck the words "oblique wing" in a
search engine, and got the following URL:

http://www.as.go.dlr.de/~helmut/h115www/H115.pdf

This seems to be saying that it is actually Mach 1.1 that you can
reach while remaining boomless. In either case, this would
eliminate the "does not fly supersonic over land" problem. And
let's face it, it's hard to turn a profit with a supersonic airplane
if it isn't *allowed* to go supersonic.

> How is this significant to space development ?

Well, I can't speak for victoriatangoman, but he *did* ask it in
relation to the space shuttle. For myself, I think that affordable
supersonic air transport is wonderful enough in it's own right, but
it might also have enough economic oomph to stimulate research into
high-speed air-breathing engines.

BTW, are there any other ways of going boomlessly supersonic?

Xenophile (who wants to make the trip, and who isn't getting any
younger)

Xenophile wrote

"And
let's face it, it's hard to turn a profit with a supersonic airplane
if it isn't *allowed* to go supersonic."

I really wonder whether or not that is true. There's some really long
routes out there that are entirely or almost entirely over water, such as
* Los Angeles - Tokyo
* Los Angeles - Sydney
* San Francisco - Tokyo
* San Francisco - Sydney
* New York - Johannesburg
* New York - London
* New York - Paris
* etc.

If the supersonic were fast enough (e.g., over Mach 2), then it would
begin to make sense to have hub traffic from other destinations (e.g.,
subsonic on regulara 757 or something from Atlanta to San Francisco) into
the overseas air gateways (e.g., supersonic from San Francisco to Tokyo).
That wouldn't make sense if the craft were just barely supersonic, because
any shortening of over-the-water time would be negated by connection time
in San Francisco. So, the craft would have to go fast enough over the
water to make up for lost time in connections.

If the craft were fast enough, then the situation might arise for which it
would be quicker to get from San Francisco to Tokyo on the supersonic than
it would be to go subsonic from San Francisco to New York. Wouldn't
that be a kicker? ! Such a capability might be a boost to the Pacific
Rim economies.

Ron

> BTW, are there any other ways of going boomlessly supersonic?

Out of my league here, but how 'bout a perfectly quiet engine?
(Not that it's possible, just wondering about the theoretical.)

Chris.

> Xenophile wrote
>
> "And
> let's face it, it's hard to turn a profit with a supersonic
airplane
> if it isn't *allowed* to go supersonic."
>
> I really wonder whether or not that is true. There's some really
long
> routes out there that are entirely or almost entirely over water,
such as
> * Los Angeles - Tokyo
> * Los Angeles - Sydney
> * San Francisco - Tokyo
> * San Francisco - Sydney
> * New York - Johannesburg
> * New York - London
> * New York - Paris
> * etc.
>
> If the supersonic were fast enough (e.g., over Mach 2), then it
would
> begin to make sense to have hub traffic from other destinations
(e.g.,
> subsonic on regulara 757 or something from Atlanta to San
Francisco) into
> the overseas air gateways (e.g., supersonic from San Francisco to
Tokyo).
> That wouldn't make sense if the craft were just barely supersonic,
because
> any shortening of over-the-water time would be negated by
connection time
> in San Francisco. So, the craft would have to go fast enough
over the
> water to make up for lost time in connections.
>
> If the craft were fast enough, then the situation might arise for
which it
> would be quicker to get from San Francisco to Tokyo on the
supersonic than
> it would be to go subsonic from San Francisco to New York.
Wouldn't
> that be a kicker? ! Such a capability might be a boost to the
Pacific
> Rim economies.
>
> Ron

An interesting scenario you portray. To expand on your scenario,
what affect do you think that floating airports, anchored offshore
would have on supersonic traffic destined for overseas ports. I
would think that flight paths would be more straightforward, going
to supersonic could happen more quickly after take-off, etc.

What would happen with hyper-sonic suborbital planes and sonic
booms? Could you have these sub-orbital shuttles taking off from any
airport and going supersonic at a high altitude and then hyper-
sonic, or would you want to restrict them to overseas flight paths
as well? In a nutsehll, my question is: if you are at a high
altitude would sonic booms there have large impact on the surface of
the Earth?

TangoMan

No doubt IF floating airports were available, THEN that would make SST
routes a bit simpler. But the enormous cost of such endeavors would, I
think, make it difficult to get any such floating airports built.

I don't know the answer to your sonic boom questions.

Ron

"victoriatangoman tango_dancer@... 12/06/2002 07:26 PM

> Xenophile wrote
>
> "And
> let's face it, it's hard to turn a profit with a supersonic
airplane
> if it isn't *allowed* to go supersonic."
>
> I really wonder whether or not that is true. There's some really
long
> routes out there that are entirely or almost entirely over water,
such as
> * Los Angeles - Tokyo
> * Los Angeles - Sydney
> * San Francisco - Tokyo
> * San Francisco - Sydney
> * New York - Johannesburg
> * New York - London
> * New York - Paris
> * etc.
>
> If the supersonic were fast enough (e.g., over Mach 2), then it
would
> begin to make sense to have hub traffic from other destinations
(e.g.,
> subsonic on regulara 757 or something from Atlanta to San
Francisco) into
> the overseas air gateways (e.g., supersonic from San Francisco to
Tokyo).
> That wouldn't make sense if the craft were just barely supersonic,
because
> any shortening of over-the-water time would be negated by
connection time
> in San Francisco. So, the craft would have to go fast enough
over the
> water to make up for lost time in connections.
>
> If the craft were fast enough, then the situation might arise for
which it
> would be quicker to get from San Francisco to Tokyo on the
supersonic than
> it would be to go subsonic from San Francisco to New York.
Wouldn't
> that be a kicker? ! Such a capability might be a boost to the
Pacific
> Rim economies.
>
> Ron

An interesting scenario you portray. To expand on your scenario,
what affect do you think that floating airports, anchored offshore
would have on supersonic traffic destined for overseas ports. I
would think that flight paths would be more straightforward, going
to supersonic could happen more quickly after take-off, etc.

What would happen with hyper-sonic suborbital planes and sonic
booms? Could you have these sub-orbital shuttles taking off from any
airport and going supersonic at a high altitude and then hyper-
sonic, or would you want to restrict them to overseas flight paths
as well? In a nutsehll, my question is: if you are at a high
altitude would sonic booms there have large impact on the surface of
the Earth?

TangoMan

Floating airports? Isn't the newest japanese airport a floating or partially
floating design?

Hong Kong?

The guy promoting Freedom Ship (the mile long floating city) supposedly has
helped build several floating structures. His linked barge system seems
pretty simple.

However I thought the push was for a low earth orbitor perhaps with scramjet
tech. Was'nt Boeing resurrecting that project? SST is old plane now.
Extremely expensive operational costs.

> No doubt IF floating airports were available, THEN that would make SST
> routes a bit simpler. But the enormous cost of such endeavors would, I
> think, make it difficult to get any such floating airports built.
>
> I don't know the answer to your sonic boom questions.
>
> Ron
> *****I
>
> "victoriatangoman tango_dancer@... > 12/06/2002 07:26 PM
>
cause?

Sorry. I didn't mean to use the term "SST" to indicate a particular
supersonic aircraft design, but rather as a generic term.

Kansai International (KIX) airport is built on landfill out in the bay. In
Japan and other densely-populated countries, landfill airports or floating
airports may be a good idea in general. But I highly doubt that anyone
will build a floating airport just to be able to make supersonic transport
more feasible.

Ron

"panamabob" panamabob@...
12/09/02 09:23 AM

Floating airports? Isn't the newest japanese airport a floating or
partially
floating design?

Hong Kong?

The guy promoting Freedom Ship (the mile long floating city) supposedly
has
helped build several floating structures. His linked barge system seems
pretty simple.

However I thought the push was for a low earth orbitor perhaps with
scramjet
tech. Was'nt Boeing resurrecting that project? SST is old plane now.
Extremely expensive operational costs.

> No doubt IF floating airports were available, THEN that would make SST
> routes a bit simpler. But the enormous cost of such endeavors would, I
> think, make it difficult to get any such floating airports built.
>
> I don't know the answer to your sonic boom questions.
>
> Ron
> *****I
>
> "victoriatangoman tango_dancer@... > 12/06/2002 07:26 PM
>
booms
cause?

I always thought the concept was cool so I bookmarked a few pages on
Floating airports. I checked the links and they're still good.

San Francisco Request for Proposal in 2000 and San Diego Artwork

http://www.floatinc.com/WhatItIs.html

Mega Float in Japan - Actual photos of the prototype - BIG

http://oceaneng.eng.hawaii.edu/~vlfs/picture_week/megafloatphaseII.JP
G

http://oceaneng.eng.hawaii.edu/~vlfs/picture_week/Mega0201.GIF

http://oceaneng.eng.hawaii.edu/~vlfs/picture_week/Mgphoto2.gif

TangoMan

> No doubt IF floating airports were available, THEN that would make
SST
> routes a bit simpler. But the enormous cost of such endeavors
would, I
> think, make it difficult to get any such floating airports built.
>
> I don't know the answer to your sonic boom questions.
>
> Ron
> *****I
>
> "victoriatangoman " > 12/06/2002 07:26 PM
>
sonic booms cause?
>
> > Xenophile wrote
> >
> > "And
> > let's face it, it's hard to turn a profit with a supersonic
> airplane
> > if it isn't *allowed* to go supersonic."
> >
> > I really wonder whether or not that is true. There's some
really
> long
> > routes out there that are entirely or almost entirely over
water,
> such as
> > * Los Angeles - Tokyo
> > * Los Angeles - Sydney
> > * San Francisco - Tokyo
> > * San Francisco - Sydney
> > * New York - Johannesburg
> > * New York - London
> > * New York - Paris
> > * etc.
> >
> > If the supersonic were fast enough (e.g., over Mach 2), then it
> would
> > begin to make sense to have hub traffic from other destinations
> (e.g.,
> > subsonic on regulara 757 or something from Atlanta to San
> Francisco) into
> > the overseas air gateways (e.g., supersonic from San Francisco
to
> Tokyo).
> > That wouldn't make sense if the craft were just barely
supersonic,
> because
> > any shortening of over-the-water time would be negated by
> connection time
> > in San Francisco. So, the craft would have to go fast enough
> over the
> > water to make up for lost time in connections.
> >
> > If the craft were fast enough, then the situation might arise
for
> which it
> > would be quicker to get from San Francisco to Tokyo on the
> supersonic than
> > it would be to go subsonic from San Francisco to New York.
> Wouldn't
> > that be a kicker? ! Such a capability might be a boost to the
> Pacific
> > Rim economies.
> >
> > Ron
>
> An interesting scenario you portray. To expand on your scenario,
> what affect do you think that floating airports, anchored offshore
> would have on supersonic traffic destined for overseas ports. I
> would think that flight paths would be more straightforward, going
> to supersonic could happen more quickly after take-off, etc.
>
> What would happen with hyper-sonic suborbital planes and sonic
> booms? Could you have these sub-orbital shuttles taking off from
any
> airport and going supersonic at a high altitude and then hyper-
> sonic, or would you want to restrict them to overseas flight paths
> as well? In a nutsehll, my question is: if you are at a high
> altitude would sonic booms there have large impact on the surface
of

>> BTW, are there any other ways of going boomlessly supersonic?

> Out of my league here, but how 'bout a perfectly quiet engine?
> (Not that it's possible, just wondering about the theoretical.)
>
> Chris.

A perfectly quiet engine (or just a *rather* quiet engine) would be
wonderful, but wouldn't do anything about sonic boom, because sonic
boom isn't caused by the engine.

I've wondered if it might be possible to "tune" the two engines of,
say, a Boeing 777 so that the noise from each cancels the noise from
the other. Or even a suped-up loudspeaker. Even a 10% noise
reduction would be significant, and a 25% noise reduction would have
those living near airports singing the praises of the first airline
to use it. I'd like to see noice cancellation used in everthing
from jet engines to leaf-blowers.

A loudspeaker to cancel sonic booms? Sorry, those things are too
much to cancel in such a way. A shockwave that can, at close range,
crack brick walls, isn't very likely to be canceled by any suped-up
(anti)boom box that can be carried by an airplane. Then again...

Double booms. Is it possible that the airframe could be modified in
such a way that the two booms are 180 out of phase? Again, even
less-than-perfect cancellation would be wonderful.

Xenophile (cranking up his antiboom box)