Posted on 10/15/2009 11:45:55 AM PDT by Arec Barrwin
Rescuers are tracking and chasing a "homemade flying saucer" that is in flight with a 6-year-old, by himself, on board.
The incident started this morning in Fort Collins when the boy got into the balloon-like device, which was built by an adult, and it came loose from a tether, according to the Larimer County Sheriff's Office.
The contraption could rise as high as 10,000 feet, the sheriff's office said.
The home-made flying saucer was last seen in flight over Weld County.
The sheriff's office is working the Federal Aviation Administration to determine how to best get the boy down.
The homemade airplane was tethered in Fort Collins when the boy got onboard and it floated away. (Lisa Ecklund via 9News)
The six-year-old boy was by himself on board the hommade aircraft. (Courtesy Lisa Ecklund, via 9News)
The craft could fly as high as 10,000 feet, according to the Weld County Sheriff's Office. (Lisa Ecklund via 9News)
At 70F, and 6000ft, a craft of 28cu.m. volume will lift a bit over 50 pounds
I think sums up the statement. The mylar, thether ropes, and the canopy structure, whether it was rigid cardboard, plywood sheathing, or baffles, would add up to around 30-32 pounds, conservatively. The “saucer shape” of the craft suggests a lower fill volume of helium than that of a spherical craft by roughly 2/3rds. I explained that a while back.
This craft, by reports got, to an altitude of about 8,000 feet, which is reasonable considering nothing on board. Its not wild exaggeration that the craft could not lift anything at all. I said it could lift probably 8-12lbs of equipment before. It is not possible that this craft could ever initially lifted a 40 pound child, given the rough schematics.
I probably also should have made clear that I used 6000ft for the altitude of Ft.Collins instead of 4980ft. If I had used 5000ft instead, the Relative Density is 80.8 instead of 77.8%.
That change would increase the lifting capability from 51# up to more than 61#.
So, IF we agree that the mass of the craft is 30# (I don’t believe that to be necessarily the case, by the way... I can see making it weigh a bit less than that)... the total weight needing to be lifted would be 70#.
I didn’t see your response before I wrote that I did the calculations based on 1000’ higher than Ft.Collins, and that change raises the possible lift to on the order of 60#.
Since I was also only guessing avg ht of 1meter high instead of what may be as much as 1.5m high with the craft completely charged with Helium (we never saw it in that state on camera) that clearly is close enough to being neutral buoyancy to be a concern, even if we stipulate that your guess of the mass of the craft is accurate.
Anyway, I think it is close enough for people to be legitimately concerned about even if the exact weight and volume of the craft becomes known for the Monday Morning quarterbacks. It seems that we’re close enough to being able to shake hands on this for now.
My brother could hide in a desk which was built into his room. He would stay there for hours to skip school, then climb out a window.
I dont think we are going to know the exact weight or make up of the craft that this guy flew. Im using simple math with known material weights. I do know that it does drop about 3 degrees centigrade for about every 1000 feet you go up. In addition, we are talking about 6000 already above sea level, regardless of the temperature. I am assuming the least weight, that being rigid cardboard, and given the pictures and numbers given, I dont see how it would come out less than 30 lbs, at the least.
Im not trying to get into a match with anyone. The guy obviously is a liar and the most importang thing is the kid is safe.
But technically speaking, a craft of this size is not physically capable of lifting a 40 pound weight given the rough diagram. Initially, it was reported that a typical 6 year old is about 60 lbs. I really didnt look up BMI or anything, but I thought something was fishy about this from the beginning.
Your full of.... bologna, there’s no way this craft could lift a 6 yo. Your being ridiculous...
The father would have known the weigh of the craft, or at least the materials that went into it, as well as the weight of the kid. He had to know what it would lift. The whole thing was a media circus... Fun, but still a circus.
Back on post 106 I said it was a hoax, it clearly was.... I’ve built helium balloons and have a good feeling for what they will lift. This one wasn’t and isn’t credible, as far as lifting a 6 yo is concerned. Somebody (not you) should have done the math...
and you are assuming that the craft was weightless? Don’t you get it? This whole thing was a hoax...
http://www.freerepublic.com/focus/f-news/2363637/posts
AFphys says hvy weight mylar is 8lbs/500ft2, so...
There's a top and bottom to the cylinder.
3.14*10ft*10ft * 2 = 628ft2 for top and bottom
sides are 3.14*20*5=314ft2
628ft2+314ft2=942ft2
942ft2 * 8lbs/500ft2 = 15.1lbs
3/4" plywood is 75lbs/4x8sheet. That's 25lbs/(1/4")thickness/sheet. Lets say the bottom was 1/2' plywood(over kill) and it was a 4ft circle (3.14*4*ft5002*50lbs/32ft5002=19.6
19.6+15.1=34.7lbs
the lift at sea level for the last calc was 109lbs. 109lbs-35lbs=74lbs. The lift drops ~3%/1000ft of elevation, so at Ft Collins' 5000ft...
109lbs*(0.97)5=94lbs
94lbs-35lbs=59lbs of net lift available for cargo. Ball Park and high... I think the balloon was for instruments, not people
"(3.14*4*ft5002*50lbs/32ft5002=19.6"
Should be...
3.14*4*ft2*50lbs/32ft2=19.6ft2
I just disagree with you in this particular situation.
The mass of the kid+Balloon is 35+44+(17,the He)/(32.2ft/sec2)=96lbs/(32.2ft/sec2)= 2.98 slugs
So the acceleration of the balloon is, 15lbs/2.98slugs=5ft/sec2
...at 5kft.
That number decreases as the balloon rises to it's max. ht., where the lift is zero. The 3% decrease /1000ft is the biggest effect and the zero will occur when the total lift equals the kid + balloon weight(35+44=79lbs).
109lbs * (0.97)x = 79lbs
79/109 = (0.97)x
log(79/109) = xlog(0.97)
x = 10.6, so the max elevation is 5600ft above Ft Collins. An empty balloon would go higher and at a higher acceleration rate...
Going back to the 5ft/sec2 accel... That 314ft2 area is really going to limit the rate of rise. I get ~4"/sec with the kid in it and 1ft/sec w/o the kid with a rough drag calc. I think the kid would have plenty of time to get out, so... Yeah, the story is rather physically impossible from the beginning.
Ma and Dad ought to be charged.
Meant to ping you to 1731. The rate of rise would be very slow with the kid.
I told you. It amazes me how some people can't see through obvious BS.
lol....I give you that.
They clearly both have some serious issues.
I was just saying there is at least one good reality show out there.
AFP tends to know what is being said about scientific matters.
What I find interesting is how all the experts have differing opinions on whether it could have carried the boy.
I am NOT a person qualified to even begin to guess, but if AFP said its possible, I believe it is possible.
Yes, if this balloon had the ability to lift 40 or 50 lbs, I would have expected it (without having done the calculcations, mind you) to rise a lot further and faster than it did. Instead it apparently became neutrally bouyant before it went much more than about 2000 ft into the air. Of course, it also apparently wasn’t made too well, or it would have held its helium and stayed up for a lot longer than it did.
Sometimes you have to go back and think like a kid...
I used to crawl in and hide in the dirty clothes hamper...Under the beds was too obvious, and closets were where the tickle monster was...
All in all I’m glad the kid was found, or came out of hiding...That’sprobably a moot point,yet the interviews following are sure leaving public opinion in a negative sense...
I do not think it was a hoax or publicity stunt...But I am going to hold out total judgment on that for a while...
These parents are loons, and need to be held accountable for the expenses incurred by their hoax.
They knew all along where their son was. IMHO, the father had to put him up there in that rafter space of the garage.
The little guy has been trying to tell the truth ever since. His father continues to encourage him to lie.
No wonder the poor kid has a tummyache and is throwing up today.
The kids have more sense than the idiotic parents.
Listen, this is all foolishness
If the balloon is tethered in the back yard, for this little tike to crawl in, he’d have to pull it down to ground level.
If he could pull it down, assuming he wasn’t using some sort of pulley system, then it wouldn’t lift him. Period...
Now you’re assuming it was floating in the air, well above ground.
It could well be tethered low to the ground - even so daddy could work on the battery bank, which allegedly had a hatch. No point having it up high where you’d have to pull it down.
You’re also assuming it didn’t have some kind of ballast to keep it low or even on the ground. Tethers could be back-up measures.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.