I read your link, and it doesn't ring true. You can't run piping on an aircraft without everyone seeing it. The sheetmetal guys would see it, the mechanics who work on the flight controls. The electricians would see the extra wire....... mechanics do specialize but these systems are all over the entire aircraft. Piping would have to be on the trailing edge and everyone works their, we trip over each other all the time and fight for position to get our work done at that location. I know every wire bundle and hydro line as I have to do my work around them. And I do not work on those systems. I have methods and plans to do my work around these other systems......

I read your link, and it doesn't ring true. You can't run piping on an aircraft without everyone seeing it. The sheetmetal guys would see it, the mechanics who work on the flight controls. The electricians would see the extra wire....... mechanics do specialize but these systems are all over the entire aircraft. Piping would have to be on the trailing edge and everyone works their, we trip over each other all the time and fight for position to get our work done at that location. I know every wire bundle and hydro line as I have to do my work around them.