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mickjoebill
8th Jan 2014, 01:07
For a few years I have been exploring the use of helicopters for warning public of approaching bushfires in remote areas by using airborne public address.
To be truly effective the warning needs to penetrate a building and ambient noise into a house, lets say with kids wearing headphones on their xbox.
Newer airborne public address kit is pretty good.

Im familiar with the latest airborne speaker technology and directional kit designed for riot and warfare


However I'm also wondering if there is a way of generating noise in other ways.
In theory we have main rotor, tail rotor, jet exhaust, compressor air bleed and aircraft 28 volt electrics to play with.

Ive excluded the use of carry on equipment.

Also effective could be a rumble or vibration… dropping flash bangs is a non runner due to threat of fire :)

mickjoebill

marianoberna
8th Jan 2014, 01:17
A locomotive style whistle powered by bleed air?

mickjoebill
8th Jan 2014, 01:35
A locomotive style whistle powered by bleed air?

Good idea! Something that creates a distinct sound is relevant.

One witness to the Royal Commission into the Feb 7th fires in Victoria stated that she heard what she thought was the sound of a helicopter but was in fact the sound of the approaching bushfire!

To elaborate the idea is to provide a bushfire warning well ahead of the fire front, lets say 10-20 kms, to give communities time to react.


mickjoebill

Flying Binghi
8th Jan 2014, 01:47
Something that creates a distinct sound is relevant...

Apocalypse Now. Ride of the Valkyries.










.

SuperF
8th Jan 2014, 02:39
Bell UH1 10' above the roof @ 120kts.

if that doesn't do it, double the mixture.

generally gets the windows shaking, wakes the babies etc. :E

Train horn run off bleed air (maybe, it would depend on the psi required, UH1 will push out 60-70 psi max, generally at 50lbs tq will produce less in the cruise, or even at 120kts), Could go just an electric one, hit the horn as you are passing over the roof top.

SASless
8th Jan 2014, 02:54
Mount this system in your Bell 204/205/212/412 Helicopter.....and Bob's yer Uncle!

Should fit in a BK-117 too.


http://www.psywarrior.com/UH1MarineLSPK02.jpg


http://ts2.mm.bing.net/th?id=H.4787974944850181&pid=15.1



PSYOP Loudspeakers (http://www.psywarrior.com/loudspeaker.html)

spencer17
8th Jan 2014, 06:07
@ SASless
and then Alice Cooper's "Fire" should scare everyone out of the house.

Peter3127
8th Jan 2014, 06:37
A 412 EP should do the trick if the local Victorian HEMS machine is anything to go by ...... :)

500N
8th Jan 2014, 06:56
"lets say 10-20 kms, to give communities time to react."

The danger is they might try to leave then and according to a mate that
lives in the Dandenongs and works in Boronia (East of Melbourne),
the last big fires were a log jam around the whole area because of
people leaving late.

Adam Nams
8th Jan 2014, 13:48
@spencer
Arthur Brown

Tango and Cash
8th Jan 2014, 14:57
Bell 214ST

Redland
8th Jan 2014, 19:58
These people may be able to help??

New Scientist (http://www.newscientist.com/article/dn24836-see-the-sound-a-helicopter-makes-caught-on-camera.html#.Us27I5H8FBW)

Mechta
8th Jan 2014, 22:57
l04qWEEPFEk

cattletruck
9th Jan 2014, 08:08
Stick a couple of ref whistles on the blade tips :}

Seriously, if it's for fire warning then the sound of a fire truck siren would make better sense. I believe they are electrically opertated.

mickjoebill
9th Jan 2014, 09:54
Seriously, if it's for fire warning then the sound of a fire truck siren would make better sense. I believe they are electrically operated.

Fire trucks go racing toward fire, but warning needs to be lets say min of 5kms-10kms and up to 20kms away on windy days…
Truck sirens are quite directional.

In oz, helicopter is an ideal way to reach both remote homes on say 50 to 100 acres and homes on 2 or 4 acre blocks on the urban fringe.. would take hours to do it by road. Agricultural folk are more switched on to watching the horizon, it is those on the urban fringe in higher density that aren't quite as connected to nature as they think they are, cosseted inside with zircon on a hot day unaware that they are in the firing line.


The warning needs to be quite a different experience to hearing a passing fire truck to create what the experts call a trigger (to motivate people)
Stick a couple of ref whistles on the blade tips

Whistles on the main rotor would be fun to try, just need to be able to switch them off every now and then!

Metch, fantastic link, Robbie Coltrane chews gum like a true mechanic…



Mickjoebill