Alright. I submit. I'm lost. I've been working on a plan for a derigible, or airship, and found that I've run into a problem. I've been using the equasion: [(H x W x L) x Pi] / 3 to calculate the capacity of the airbags within the derigible. I don't think this is correct so please help me there if you can. Anyway, the real problem is I don't think my results are acurate. I have looked up helium's lift capacity and found that it is 1 m3 can lift 91.82566798 grams, or 0.2024409 pounds. This seems logical, but that's not the problem either. After calculating the entire derigibles helium lift capacity (4869.468161 m3), I have found that it can only lift about 4471.4216659116718478 grams, or 985.77973565 pounds. This does not seem acurate seeing as the airship has 20 airbags ranging from 7x7x7 m to 12x8x7 m. I would think it could lift a bit more but, I am rather unexperienced in this field. Can someone please confirm my calculations?