The mixing unit
I disassembled a mixing unit earlier this week. I've never taken one apart before, so that was kind of cool, but it's actually not that complicated. It takes the forward-and-back and side-to-side motions of the cyclic stick and uses levers (we call them bellcranks) to translate them into into the up-and-down motions the main rotor head assembly needs to tilt the blades so the helicopter will go where you want it to. (I'm also making it sound more complex than it is...) It's a big bunch of levers and plastic bearings, but the whole assembly together is kind of expensive, and even at the level of maintenance we do in the shop, we're limited in how much we can repair it.
The reason I mention the mixing unit is because it takes me back to the first couple of months I was working here. I was picking up a parts order from our receiving inspector and he handed me this big box along with the rest of my stuff. When I asked him what it was, he looked at me like I was nuts and said "It's a mixing unit." And I'm thinking, Huh? "A what?" "A mixing unit." "What mixing unit?" What does it mix? Air? Fuel? "The mixing unit you ordered." Uuuummm.....that's got to be an engine part, right? "I didn't order a mixing unit." "Well, it's got your name on it." So I carry the thing up the ramp into our hangar, and the whole time I'm thinking what on earth is a mixing unit??? I've never even heard of this thing! Where does it go on the helicopter?? How the hell did I manage to order one?? And as I'm walking through the hangar, all my coworkers are like "What'd you get?" "Oh my god, you ordered THE WHOLE MIXING UNIT??" "Why'd you order the whole mixing unit?" And again, all I can think is What in God's name is a mixing unit?????? And of course, I keep asking people "What is it?" and they're like "The mixing unit!" And all that does is confuse me.
As it turned out, I didn't order it- the receiving inspector misread the paperwork and somebody else had ordered it. But it was probably another two weeks before I finally figured out what a mixing unit was.