I agree!! I think they made them "dangerous" so they could sell tickets on planes for profit!! Kinda like making light bulbs less efficient and therefore more profitable!! The Lindenberg burned in 1937 and the Wright bros flew in 1903 so that was 34 years to come up with the scheme...

Im no scientist at all so i dont know of any gasses that would not go boom. If there are and there is a way to harvest the gas while aloft then we would certainly have a plausible and safe(r) way to travel. As far as an expedition goes i would think the ability to harvest the gas while aloft would be a requirement. An HHO generator works via electrolysis separating the hydrogen and oxygen from water. These ships were known to collect ice on them so that alone without any other water collection system would be enough to BOTH replace the hydrogen on voyage AND supply the crew with oxygen at height...

Cool stuff when the universe pulls you in a specific direction along with others at the same exact time!! Who knows maybe it will be YOU taking this voyage!!