Hindenburg

(this is one of the New Jersey disasters)

Dr. Hugo Eckner, the chairman of the Zeppelin Company had originally intended for the Hindenburg to use helium, which is not flammable. Unfortunately, the only known natural deposits of helium existed in the United States. The American government was afraid that the airship could be a dangerous threat if used for military purposes. Congress passed the Helium Control Act which made export of helium to Germany illegal.

• The skin of the aircraft was doped with aluminum powder, iron oxide and cellulose acetate. This made it look nice and shiny.
• Powdered aluminum and iron oxide are primary ingredients in the Space Shuttle solid rocket boosters. It is a very explosive mixture, though they didn't know it at the time.
• The skin of the craft was made of large panels of cloth tied to the airframe
• Airships tend to build up large static electrical charges during flight
• The cord that tied the panels to the airframe was not conductive and so the charge that built up in the panels was not grounded when the mooring rope touched the ground, as it should have been.
• It had just rained, so some of the cords were wet and conducted the electricity to ground. But this left a high electrical potential between the drained panels and the undrained.
• The resulting arc ignited the doping material and caused the disaster, as stated above, hydrogen had nothing to do with it.
• This was all known to the Zeppelin company from their investigation, but they covered it up and publicly blamed hydrogen.