h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I want an object which, when pulled through the air at about 20-25mph, whistles. I may wish to tow it behind a bike or car on a string, say. (I actually want to tow it behind a paraglider...)

I'm picturing something like an organ pipe on a length of paracord or similar. Does such a product exist?

If not - how would I go about making one?

Traveller on Time
"try a corrogated hose, the ridges inside make the flow of air resonate, creating an eery foghorn like sound."

I can't find anywhere that sells such a thing.

The only instruments vaguely similar sold on the web are bullroarers and windwands, but they're designed for swinging around your head on a string. I don't know whether they would work if trailing behind a paraglider.

The top of a tin whistle (Generation model) will play a note if the wind blows through it but you would have to position it on some sort of an aerodynamic wing to keep it at the right angle to the wind.

http://larkinam.com/Roar.html

Can't you just tow a tradesman behind your glider?

Sporting goods shops (for hunters and fishermen) over here sell a small whistle affair that attaches to the front grill of a car or truck. At driving speeds, the air-flow causes a "whistling" to alert moose and deer of something coming ...

You might find such a thing, and modify the mount to attach your length of shroud line.

http://www.amazon.com/Living-Products-LLC-0001-Save-A-Deer/dp/B003XNGLJU

I did a quick search and came across something called a "kite whistle".

You might look into those.

I can't find anyone who actually sells kite whistles.

Deer whistles are a non-starter for two reasons:
1. the noise they make is inaudible to humans
2. they only work above 35mph, and my airspeed is more like 20-25mph.

Nice idea with the windwand, though - I'm definitely going to make one of those

Sometimes doing an image search can provide the serendipity to find what you're actually looking for.

http://www.amazon.co.uk/CHILDRENS-WHISTLING-THROWING-ROCKET-BUZZ/dp/B004WP18DM?ie=UTF8&*Version*=1&*entries*=0


(And sometimes you forget which thread you last read and post a non sequitur. )

Also recommended on that page: Nerf N-Sports Mini Vortex Howler


which seems to be more the thing.

Can't you just tie a kettle whistle behind you?

*ducks *

I now have a Vortex Howler and a pack of large elastic bands (for making a windwand) on order. Will report progress (if any) in due course.

My uncle made a bull roarer out of a coworker's car by stretching a large rubber band from two points under the vehicle. Of course, the coworker didn't know it was there. Once he reached a certain speed it made its sound and every time the coworker slowed down to find what was wrong with his car, the noise stopped.

Another time, my uncle slipped a tape player under this coworker's car seat while he wasn't looking. After he was about 15 minutes down the road, he'd start hearing my uncle's voice saying his name at random intervals. (My uncle was his supervisor and was used to hearing his name called repeatedly each day.)

The two had a strained friendship.

Actually I thought the best part of floating through the air was the fact that no one can hear you.

Well, yes, normally - but this is for a festival. The endpoint of the afternoon is a bunch of us get helicoptered up to the top of a mountain overlooking the campsite/festival ground, and all launch speedwings at once and come plummeting into the field. Normal procedure is fancy dress, but this time I thought I'd add an audio element to it all.

If I were to do that I think you could guarantee an audio element.

Well I can report the following:

The vortex howler was no use - towed on a line it didn't line up with the wind flow AT ALL, and I'm possibly not flying fast enough. Either way, no noise at all.

I did, however, buy a bunch of dowelling and some balsa wood and spent 30 minutes with a drill and a jigsaw making a windwand. Towed behind the glider this worked A TREAT, and makes a rather good droning noise. I'm not sure how loud it is and how well it can be heard from the ground as I'm obviously right next to it the whole time. On my test day I was the only one on the hill.

I have some plastic tubes that will be made into a form of towable wind harp. More reports when possible.