🚀 go-pugleaf

Marco Desloovere wrote:

> ahennell [Wed, 22 Jan 2003 01:48:59 GMT] wrote:
>
> >Marco Desloovere wrote:
> >
> >> I was wondering whether it would be possible to blow out the Canberra
> >> fires using helicopters? Just like one would blow out the flame of a
> >> candle...
> >
> >- Energy required to "blow" out a fire would be phenominal.
>
> How much is "phenomenal"?
> More than a couple of your most powerful helicopters?
> If it cannot be calculated, then it's obviously a trial and error
> thing.

Have you ever stood between a bushfire and a house?  Have you ever 'felt' the
beast as it approaches?  At 50m, the heat is unbearable.  The energy of a
fire is far beyond what a helio could hope to overcome.

> The point is that if my method were applied *before* the fire gets out
> of hand, then no phenomenal force would be required later.
>
> I think that it might be worth a try!

In the wilderness?  You wouldn't get close enough for all the trees - the
only effect would be to fan the fire & spread embers.

> >- Smoke usually travels with the fire - in the direction you'd have the
> >choppers approaching from - stopping any visability
>
> This could be co-ordinated from the ground using adequate electronic
> devices, if really necessary.
>
> >- Formation flying that close to eachother, and that close the ground is
> >never a good idea at the best of times (SAS & Blackhawk?)
>
> Indeed, and it would require some excellent pilots and also good
> co-ordination from the ground!

Fire creates its own weather - updrafts, fire tornados, winds - it's hard
enough flying through when you're a sole aircraft at height, let alone
getting close enough to trees, powerlines, houses, etc to 'blow' anything
onto the fire.

> >- Wouldn't produce enough 'wind' to make much effect
>
> That remains to be seen. Big choppers can create quite a big thrust!

They don't 'blow' air, they rotate their wings through it.  yes, there's
significant downdraft from them, but it's not like a fan sitting in the air.

> >- You'd end up, if anything, spreading fire more than putting it out
>
> That is a possibility which could only be observed, if the operation
> were tested in real life.

Have you watched wind gusts & their effects on fires?

> >- Heat of the ground will simply reignite anything you do manage to blow
> >out
>
> That heat would be much easier to control than a raging fire!

A bucket drop works because the initial gust of cold air & water quenches the
fire, and the remaining water helps stop reignition.  Air alone would have a
very difficult time in stopping that reignition.

I have personally seen fires put out, only to watch leaves fall to the ground
& spontaneously ignite.  You are underestimating the heat component.

> >- The energy of a moving fire front is simply massive.  These fires give
> >off the equivalent force of many hiroshima bombs during their burn.
>
> Yes, indeed. That is why my method should have to be used as quickly
> as possible, to avoid the beginning of real massive fire.

Again, where these fires start there is no way of getting a chopper that
close to do any effect.  Let alone any ground controll.

> >Nup, I can't see it working.
>
> It may have to be tried on a small scale first, to see whether it
> *really* doesn't work...

Well, off you go.  This isn't putting iron wheels on a car & sending it along
tracks, it's something that, when you consider all the components of the
operation, would simply not work.

May I ask:  Are you a firefighter? A pilot?  Have an understanding of fire
behaviour or flight theory?

Andrew :o)