Installs, diagnoses and repairs the electronic systems an aircraft depends on.

Avionics technicians work on the aircraft itself: navigation, communication, flight control electronics, wiring looms. It is a licensed trade with a clear ladder, and it does not require a degree.
The main route. Paid from day one, with the licence earned along the way.
Service technical trades convert well into civil licences.
Aircraft and avionics equipment mechanics and technicians · US Bureau of Labor Statistics, Occupational Outlook Handbook, May 2024 wages and 2024–34 projections.
Published together with airframe and powerplant mechanics. The Handbook gives $81,390 for avionics technicians specifically.
Modern aircraft systems fail in ways that do not present cleanly, and you are expected to find the fault, not replace boxes until it goes away. Night shifts, and the aircraft is needed in the morning.