@farmerman,
Once more farmerman there is no way such a small balloon can get off the ground under the laws of physic with this child in it but if you wish to believe it be my guess.
The man in the chair used 40 plus full size weather balloons if memory serve me correctly.
See below the comments of another gentleman that can do simple math that you do not need to be a PHD to do and came up with the same numbers I did.
http://www.adrenaldesign.com/blog/1/09101558
A little back of a napkin math later (assuming the craft was about an oblate spheroid (v=(4/3)Πa²b) ) I found that this gave the craft about 1,000 cubic feet of helium, which is 28,500 liters. Now this ignores what certainly looked like a giant dimple in the top in a few photos, I wanted to give this whole fiasco the benefit of the doubt, but I digress.
A liter of helium weighs about a gram less than a liter of air, giving it about a gram of lift (assuming both are at standard temperatures and pressures). This means that the gas inside a craft like the Heene's that is 30 feet across and 8 feet tall would be able to lift about 28.5 kilograms, which is just over 60 pounds.
That's just over 60 pounds of total lift, so the weight of the balloon and box structure would be included in that. Given that the average 6 year old boy weighs around 40 pounds, and that the conveniently opaque box on the bottom of the balloon looked like it could easily weigh 20 pounds, this whole thing seemed extremely unlikely.
Turns out I was right.
Not only was I right about the boy having never, ever, been in the balloon that we shut down an airport for, but it turns out I was extra right about the craft being completely incapable of carrying the poor child.
The balloon was actually 20 feet in diameter, and 5 feet tall (I've confirmed that these measurements are reasonable by comparing standing people to the craft shortly after landing). That gives it a lot less lift.
A balloon that size will be able to hold about 7,500 liters of gas. That's 7.5 kilograms of lift, for those of you not well versed in the metric system, that's about 17 pounds. Seriously, by my calculations the gas in that balloon couldn't carry a chubby toddler, much less a six year old and that (again, conveniently opaque) box on the bottom.
How, I wonder, did the father not realize that the balloon he designed and built wasn't big enough to lift a kid? How did he miscalculate the lift of his own balloon by such a gross margin? Could it be that reality TV appearing parents would grossly misuse their own child for publicity purposes?
Just in case you forgot, science is real, bitches.