Probably not negative, but component maintenance is a huge longtail revenue stream for avionics. Pretty much every electronic and mechanical component has to be pulled periodically and tested, which costs, and replaced or refurbished. My first proper job, that's how they made the majority of their revenue. They lost money on the development effort, maybe broke even after initial sales, and profited off the fact that aircraft are kept around for decades and every 5 years their part had to be pulled and sent back to them for testing and replacement.

The more Airbus or Boeing own inside the aircraft, the more they can play into this model. 787 is a great example of Boeing hurting themselves through their outsourcing, but greatly assisting their suppliers.

yes, what you're talking about is true for the supplier side, but it's still not accurate for A/C mfg. operators own the a/c and all the associated bits that would end up getting sent out for service, and they're the ones that are paying service fees to those OEM suppliers that supplied the A/C in the first place.

these day's there's not many "parts" outside of fuselage and flight IP that someone like Boeing/EMB, etc. owns that wasn't outsourced:engines, air data system, actuations, cabin, flight controls, landing gear, etc.. THere's nothing really that the A/C mfg could "service" to ever make back a 300mil airframe. the A/C sell for the fixed cost, sometimes the operator gets to select their own engine, but othewise they buy it for cash, not for future services. boeing and other A/Cs would not survive on maintenance plans because there's very little they actually maintain.

Yes, now you say that, I think what I read was actually about the engines.