Funny you should swa about planes, I changed a couple of lights in a factory the other day round here, you know the big rubber door seals on planes and the rubber window seals, well this company make the moods that the rubber seals are made in, they CNC them, then another company do the rubber bit.
They said there's far too much legislation etc making the actual bits for the planes so they just stick to to the tooling, apparently there's only 4 companies in the uk that make the molds. He drowned me round the place, it was quite interesting, as was the mess of the wiring.
I could find the breaker to switch off his office lights, despite putting an mcb finder on it, no such joy.