PDA

View Full Version : OT: Article about antiquated firefighting aircraft includes umbelievable claim.



winchman
12-23-2012, 03:43 PM
From: http://openchannel.nbcnews.com/_news/2012/12/23/16073369-despite-warnings-aging-firefighting-aircraft-still-flying-and-crashing?lite

"Pilots say they have seen giant rocks and tree stumps thrown into the air – sometimes hitting planes – due to the powerful convection forces created by intense forest fires."

I'm really skeptical about this claim. Any believers?

Machine
12-23-2012, 04:04 PM
Sounds like utter BS. All I can figure is that if a large rock is superheated, trapped moisture converted to steam inside the boulder can cause it to explode, possibly throwing off rock debris at high velocity. Can't see it making a stump fly up high enough to hit a low flying plane though.

garagemark
12-23-2012, 04:22 PM
Maybe cold water hitting a super heated rock could shatter it sending shrapnel around. I can't imagine lumber doing anything but splintering.... but I've never been there. In other words, I can't just call BS.

topct
12-23-2012, 04:50 PM
I believe that stuff does get sucked up from the forces. And I would not be surprised if some of it did strike the aircraft on occasion.

How "giant" the rocks are and the size of the tree "stumps" sounds like something the "new guy" should hear about. :D

The Artful Bodger
12-23-2012, 06:10 PM
Yea, and I have heard about swimmers being scooped up from lakes and rivers and dropped on forest fires!:rolleyes:

uncle pete
12-23-2012, 06:23 PM
Hey it's the internet. Of course it has to be true:rolleyes: Just like everything you see on the news is true...........................right? Never let the facts get in the way of a good story.

Pete

Willy
12-23-2012, 06:58 PM
Having had the opportunity to serve in ground support at several major forest fires in the past I can vouch for the fact that the intense convection from firestorms do in fact toss some sizable chunks of limbs and trees high into the air.
"Giant" rocks being thrown through the air, I can't say for sure as I've never heard of it.
But given the right, albeit rare conditions, I would not be totally surprised.

Unless one has witnessed the massive amounts of energy released by a forest fire first hand I can appreciate the skepticism.
When conditions are right and these forces are focused it is indeed a very scary sight.

This from an inquiry into the Victorian bush fires of 2009 in Australia.

http://www.royalcommission.vic.gov.au/Submissions/SubmissionDocuments/SUBM-002-059-0366_01_R


The fires developed into “firestorms”. Enormous quantities of air were being drawn into the fire combustion process involving burning forest fuels. Following combustion, this air was displaced upwards in the convection column above the fire, creating an area of low pressure near the ground. To replace the displaced
air and fill the area of low pressure, air rushed into the area beneath the convection column from all directions at extremely high speeds. Winds of extreme force tore large gum trees from the ground at the roots and snapped large tree trunks. Although there does not appear to be any recorded scientific data of local wind speeds on 7thFebruary 2009, empirical evidence from previous fires studied indicates these very localised winds can reach cyclonic speeds (150 kilometre per hour wind speeds were estimated during the 2003 Canberra firestorm.

Weston Bye
12-23-2012, 07:09 PM
I sing in a choir at church. The choir is big enough that the director admonished us to stagger breathing when singing a particularly energetic passage. Seems that everyone inhaled at once and the resulting draft pulled the bulletins out of the hands of the congregation in the first three rows of pews.

(God may punish me for that one)

I do recall reading a story in Live Steam magazine about a locomotive losing the fire in the fire box when the loco lost traction on a hard pull up a steep grade. Sucked the coal bed off the grate, through the firetubes and up the stack, leaving the fireman struggling to rebuild the fire.