Module separation
I've been doing engine work for three days now. Let me just say right off the bat that I am....oh, let's call me a chronically anxious engine mechanic. I don't do a whole lot of engine work- there's so much more to do on the airframe, and the engines that go on the AStars are relatively trouble-free most of the time. So I don't get a ton of practice. Also entering the picture is that, well, it's the engine. There's not a whole lot of margin for error. Perhaps it's different if you're a fixed-wing engine mechanic, given that fixed-wing aircraft have a glide slope and can drift gracefully down from on high into the nearest open field or road or whatever other clear, relatively flat space the pilot can find close by if his engine suddenly goes belly up. The helicopter doesn't really want to glide at all- it has the aerodynamics of a set of car keys if the rotors aren't turning, and while there is this thing called an autorotation that the helicopter can do in the event of engine failure, that's really more of a controlled crash, and it doesn't always work. So I feel I have good reason.
However....
...jet engines are really, really cool. They're part of the reason I got into helicopters in the first place (I hate piston engines- too dirty, too many moving parts, too inefficient. Very unsexy. And while there are helicopters out there with piston engines in them, they're less common). For example, the AStar has a max takeoff weight of just over 5,000 pounds- that's just under 3,000 pounds of aircraft and just over 2,000 pounds of fuel, passengers, cargo, etc. The engine that lifts all of that tips the scales at just over 200 pounds and would sit comfortably on my kitchen table. And it doesn't get any help at all from forward momentum or lift under those huge wings that engines on fixed wing aircraft get. Nope, it has to haul all 5,000 pounds into the aviation equivalent of a dead-lift. I think that's pretty amazing.
So what I've been doing for the last three days is removing the compressor module and the gas generator module (the combustion chamber and its accessories and housing) from the rest of the engine and getting ready to ship them back to the manufacturer. They're rentals, and we should be getting our newly-overhauled compressor and gas generator back in about two months. I've learned a lot, and it's been fun. I'm nervous about putting it all back together (two months is a long time to remember everything!), but if I do it right, seeing this one start up and lift off the first time will really be something special!