Boeing is having a rough time of it right now, with parts falling off its planes left, right and center. Just last week, a wheel came loose and smashed through a car, and earlier this year the door from a 737 Max aircraft broke off mid-flight. That mid-air disaster sparked an audit from the Federal Aviation Administration, which has gone far from well.
The soap wasn’t used as a leak indicator, it was used as a lubricant to put the rubber door seals onto the metal airframe. Distilled water with a tiny amount of surfactant is a very common fitting lubricant as it leaves very little residue once dried.
The card was a feeler gauge. Not knowing if it’s the appropriate thickness is exactly what makes it inherently bad.
They could get both of these things from approved manufactures made to the standards and specs required for aircraft manufacturing. But it was cheaper to buy dish soap and hotel cards.
Boeing CEO, David Calhoun, has a salary of over $6m and takes home $22m with bonuses.