During my Saab-era, my mechanic was also-too: an aircraft mechanic.. there's no such Thing as "over-qualified" where brainz must be employed. (Had I my own aeroplane, I'd have meant to acquire similar chops; after all, it's just another internal-combustion device--only the possibilities of error are: 3-D {always stay a little-afraid..} rather than 2-D).

tl;dr ... (Moi Wants aircraft-grade folk! workin on my stuff; alas, Loren's no longer available.)

Sample: Loren + I tracked down an intermittent Starter condition: some yahoo had installed an after-market 'security' thingumbob which operated via the necessity of a slide-in tiny card (usual 'lectronic-size pieces within). It was IN SERIES-with the heftier than normal line to the starter solenoid. And the installer had used the smaller-size wiring--all the way down--ergo: the solenoid, instead of forcefully whacking its designed hi-current repository ... just sorta slid-in. As in Duh. Replace wire/shit-can the device; forget installing that spare starter motor+solenoid. A shop, I wot: would just have done the swap; it'd work OK for awhile ... again. (We both copped to the problem, just seeing the skinny wiring.)

This damn clusterfuck had nearly left me stuck in a parking lot--at near 32F--in Flagstaff late one dreary wet evening. Planning a Heads-Up to the gadget's non-engineering dept was next, a FAIL:
out-of-Business. er, QED.