Another Concorde question: Sonic boom and other planes?

[MitchT]

My understanding is that Concorde wasn't allowed to fly super-sonic over land because of the disturbance and possible damage that the sonic boom would cause to people, animals and property.

So, what would happen if you were sat minding your own business, mid-Atlantic at 38,000ft, on a 767 etc. and Concorde flew overhead, maybe overtaking in the same direction or perhaps heading the other way? Would you hear the boom? Would you feel the shock wave? Was Concorde and other planes kept apart for these very reasons?

[Talksteer]

The pressure wave from a high flying aircraft is more of a noise nuisance than anything else, low flying planes doing supersonic speed can actually do damage but even then its only really weak structures that get damaged.

http://www.youtube.com/watch?v=znlBMHFdCEY

Given that you would be in a pressurised robust structure, with a fairly high noise background I would be surprised if you would notice it.

The transatlantic baloonists did though.

[Eric Mc]

And people on ships.

And people living in Cornwall and the Southwest of Ireland.

The Space Shuttle always delivered a double boom as it swooped in over California or Florida.

[Tango13]

The strength of a shockwave is dependant on several factors. Air density, the length and weight of the object breaking the local speed of sound and it's relative pitch ie whether it is climbing or diving.

When the USAF were flying the XB-70 NASA asked them to help with sonic boom research as it was of a similar size to the proposed SST.

The problem was while the XB-70 was of a similar physical size it was much heavier so to gather meaningful data the XB-70 had to be flown with the bare minimum of fuel to conduct the tests, something the pilots were not happy about.

[Chuck328]

A definitive answer?


Quote:

" I do have a fond memory of one flight out of JFK; we were temporarily 'held' by Boston ATC to Mach 1.6 (and at around FL440) because of an Air France Concorde heading for JFK. We saw this guy above us, at around FL580 on a near reciprical , doing Mach 2, screaming straight over the top of us. We were excited by this amazing spectacle, and so were the AF crew over the VHF ('you never boomed us, did we boom you?'). But the most excited person of all was this guy in Boston ATC. ('I've never seen anything like it guys, your two blips whistled over each other on my my screen like crazy')."

Taken from a post by M2Dude on pprune.

If any of you are interested, a chap on that forum asked a technical Concorde question, the result (over a few years now) is some eighty plus pages of Concorde Q's and A's, most of which are answeered by M2Dude (apt username) and ChristiaanJ. It gets quite technical in places but still fascinating stuff if you like that kind of thing.

http://www.pprune.org/tech-log/423988-concorde-que...

[bulb763]

Chuck328 said:

If any of you are interested, a chap on that forum asked a technical Concorde question, the result (over a few years now) is some eighty plus pages of Concorde Q's and A's, most of which are answeered by M2Dude (apt username) and ChristiaanJ. It gets quite technical in places but still fascinating stuff if you like that kind of thing.

http://www.pprune.org/tech-log/423988-concorde-que...

+1

I check that thread every couple of months or so. Completely facinating, particularly when it gets technical Former pilots also add their 2 peneth and even, I seem to remember, cabin crew, with some great anecdotes.

[Guvernator]

bulb763 said:

Chuck328 said:

If any of you are interested, a chap on that forum asked a technical Concorde question, the result (over a few years now) is some eighty plus pages of Concorde Q's and A's, most of which are answeered by M2Dude (apt username) and ChristiaanJ. It gets quite technical in places but still fascinating stuff if you like that kind of thing.

http://www.pprune.org/tech-log/423988-concorde-que...

+1

I check that thread every couple of months or so. Completely facinating, particularly when it gets technical Former pilots also add their 2 peneth and even, I seem to remember, cabin crew, with some great anecdotes.

Thanks Chuck, just started reading that thread and it's fascinating stuff. That's now work done this afternoon then

It has made me realise two things however.

1. What an amazing piece of engineering the Concorde was, a passenger plain which could fly faster and higher than most military jets!

2. Bitter disappointment that once again, economics and politics seem to have have got in the way of technological progress. I've often wondered how advanced we would be as a human race right now if the politicians and accountants didn't rule the world. We could have all been flying around at supersonic speeds at the very least.

[Eric Mc]

Technical progress never happens in a vacuum. It happens in response to social, economic or political needs.

There must be reason other than "hmmm, that would be a fun to do" when embarking on a project that will require lots of money, especially if it's other people's money.

[Simpo Two]

Concorde, Apollo, Harrier - all 1960s and all unbeaten. But as Eric says, passengers don't want to fly at Mach 2 any more, nobody wants to go to the moon and nobody wants to take off vertically.

No need + no interest = nothing.

[TheEnd]

http://en.wikipedia.org/wiki/Oklahoma_City_sonic_b...

[Guvernator]

I understand that the world we live in revolves around money but doesn't mean I have to like it

My whole argument was based around that fact that if it wasn't thus, mankind as a whole would probably be a lot more advanced, things could be researched\invented because they would make all our lives\easier better and not just because they made money.

Anyway enough derailing of this thread, back to sonic booms. Did Concorde also produce those awesome contrail effects too as it broke the sound barrier that you often see military jets producing?

[Eric Mc]

Guvernator said:

I understand that the world we live in revolves around money but doesn't mean I have to like it

That's not what I said. Engineering projects need motivation first. If the motivation is there - the money will flow.

Neither Apollo nor Concorde were embarked upon for commercial reasons. Politics was behind both of them, - and consequently, especially in the case of Apollo, it was politics that brought about their end.

[Eric Mc]

Guvernator said:

Anyway enough derailing of this thread, back to sonic booms. Did Concorde also produce those awesome contrail effects too as it broke the sound barrier that you often see military jets producing?

Probably not. Those types of condensation tend to occur at lower altitudes. Concorde transitioned to supersonic flight when it was fairly high up.