Accidental Supersonic?

[Nuclearsquash]

I was thinking about this last night.

I rember as a wee nipper going with my dad, to the Bournemouth Airshow ~1987, and watching a Tornado F3 go supersonic. However these days at airsohws everything is all subsonic for various reasons, but what would happen if a displaying aircraft accidentally went supersonic? Would the pilot just get a slap on the wrist or worse?

[Simpo Two]

I don't think you can 'accidentally' go supersonic - it's not like going from 70 to 71 on the motorway.

[Nuclearsquash]

Ok then 'accidentally' on purpose, or sneezes whilst throttling up

[bleesh]

Time for everyone to dig out those YouTube clips of the US fighters going supersonic over the ships and at the airshows

(I can't as the damn firewall doesn't allow me to access YouTube from work)..........

[Eric Mc]

Did you hear the bang?

Up until the mid 1980s it wasn't unusual to see fighters nudge the sound barrier. F-104 Starfighters did it frequently and a French Navy Crusader got awfully close at the 1987 International AIr Tatoo at Fairford.

But I never heard a true supersonic run. They more or less stopped doing them by the end of the 1950s.

[Nuclearsquash]

Definitely heard a bang, and alot of car alarms started going off to. I think they also got a lot of complaints that year as well.

[Le TVR]

Simpo Two said:

I don't think you can 'accidentally' go supersonic - it's not like going from 70 to 71 on the motorway.

Tis not so difficult.

Speed of sound is proportional to the square root of absolute temperature.
It only needs a local temp inversion, abrupt weather front etc and unintentional excursions are possible.

[NDT]

I have a vague recollection of reading a site written by an ex-Victor pilot where IIRC he talks about accidentally going supersonic.

[Flintstone]

Le TVR said:

Tis not so difficult.

Speed of sound is proportional to the square root of absolute temperature.
It only needs a local temp inversion, abrupt weather front etc and unintentional excursions are possible.

I've watched the machmeter fluctuated under just these conditions (around M.80-84 so no danger of bits falling off).


<adopts misty eyed gaze>

I remember as a lad waiting on the doorstep in London to hear Concorde go supersonic during flight tests before 'they' put a stop to it.

[Tango13]

I've read an account of a Lightning display pilot who accidently went supersonic due to the weather conditions. The previous days display had been fine but a decrease in tempreature and an increase in air pressure was enough to push him supersonic. He destroyed a couple of hangers/nissan huts and all of the glass in the control tower.

[mrmaggit]

Tango13 said:

I've read an account of a Lightning display pilot who accidently went supersonic due to the weather conditions. The previous days display had been fine but a decrease in tempreature and an increase in air pressure was enough to push him supersonic. He destroyed a couple of hangers/nissan huts and all of the glass in the control tower.

"Ah, negative on the fly-by, Ghost Rider, my desk is covered in glass"

[tank slapper]

Tango13 said:

I've read an account of a Lightning display pilot who accidently went supersonic due to the weather conditions. The previous days display had been fine but a decrease in tempreature and an increase in air pressure was enough to push him supersonic. He destroyed a couple of hangers/nissan huts and all of the glass in the control tower.

He won't have destroyed anything, but he might have broken a window or two depending on how low the pass was. A sonic boom isn't like a bomb blast, it's just a loud bang.

[TheEnd]

That is one thing I probably never hear now.

[Tango13]

tank slapper said:

Tango13 said:

I've read an account of a Lightning display pilot who accidently went supersonic due to the weather conditions. The previous days display had been fine but a decrease in tempreature and an increase in air pressure was enough to push him supersonic. He destroyed a couple of hangers/nissan huts and all of the glass in the control tower.

He won't have destroyed anything, but he might have broken a window or two depending on how low the pass was. A sonic boom isn't like a bomb blast, it's just a loud bang.

The book was "Never in Anger" by Anthony "Bugs" Bendell. He also describes light fittings hanging from the ceiling, stud walls being dislodged and most of the equipment belonging the meteorological officer being destroyed. He also ended up in a courts martial for the fly by but was fully exonerated as the display was authorised by an ACM or similar.

The over pressure of a shock wave can vary massively depending on the speed, size, weight, length and AoA of the aircraft making the boom. NASA wanted to use the XB-70 for sonic boom research for the proposed SST program but the test pilots were not happy about flying it at such light weights needed to simulate the SST.

[Pigeon]

I remember being on a boat in mid-Channel when Concorde went over and the whole cabin roof went boioioing from the sonic boom. I can quite imagine that the boom from a lower-flying aircraft would be able to destroy a less flexible structure.

[Chuck328]

http://everything2.com/user/archiewood/writeups/ai...


Bottom of the page, China Airlines 006

[IroningMan]

When I lived in Berlin in the 1980s the other side would frequently make supersonic runs over the western half of the city - to help us celebrate Christmas, for example - and the concussive effect was noticable in terms of rattling windows and so-forth.

[Seight_Returns]

There's a (quite possibly apocryphal) story of a Lightning capsizing and sinking a Russian spy trawler as a consequence of a very low, very fast overflight.

[Eric Mc]

Seight_Returns said:

There's a (quite possibly apocryphal) story of a Lightning capsizing and singing a Russian spy trawler as a consequence of a very low, very fast overflight.

I like the idea of a Lightning singing.

[Seight_Returns]

In before the edit - too fast for me Eric !