f-a: You will know the Marketing academic “Gillette” Case – give away the razor free, charge like wounded bull for blades. Mrs.ak chose a kitchen bin that has a size of liner not offered by the “generic”, own brands, so I pay muchly per binfull. So, with airliner “rotables” – components that turn and burn, erode, and cost muchly to repair/replace. Like engines.

So many cost elements in airline operations are not open to management to reduce – like fuel after a hedge expires, or nav fees, or airport fees. Maintenance can be eased, so must be, to give Operator A an advantage over B. But safely. So:
a) certified, traceable, legitimate-service-history used parts are an “of course”. So, now, is:
b) Parts Manufacturing Authority (PMA) generic, own brand high-usage consumable parts (like UK car exhaust firm Kwik-Fit). No sane operator buys such things from the OEM. Now, load-bearing, or fatigue-sensitive items…ah, well, better talk about that.

Original Equipment Manufacturers have now abandoned trying to shut this sector down, and have bought into it. Airbus Industrie is setting up a Steptoe salvage operation, both eco-green, for non-toxic disposal, and to ensure legitimacy in re-used parts. All 3 big engine OEMs now offer overhaul service and PMA parts on competitors’ engines.

It’s all entirely right and proper…if honestly handled. Much effort is put into this by National Regulatory Authorities. If you choose to fly on a legitimate carrier – such as any Regulated by EASA – you need not concern yourself with this issue.