I am curious; what would be considered the minimum number of hours that an aircraft should be flown for piston engines, turbo props and jet, before corrosion becomes an potential issue?
It think it is generally believed that a piston engine of the old style (Lyco/Conti) should be run every 2 weeks or so, and for not less than about 1 hour to make sure the water condensed into the oil gets boiled off.
In a dry climate, longer periods ought to be fine.
I also think it depends on the oil. Also the Camguard additive really does work very well (for both wear reduction and helping the oil stick between engine runs) and this is supported by good data.
Jet engines are not my area, but I think it's fair to say that the high strength / high temperature alloys used in them which are exposed to the outside tend to be pretty resistant to corrosion, and together with pressurised (sealed) hulls you get a better ability to park outdoors. And indeed most jets live outdoors all their life.
Avionics life versus outdoors etc is something where opinions differ a lot. Different people have different experiences. I don't like it when I get in and see the panel covered with condensation. Look inside any avionics repair shop and you see that corrosion is very obviously the biggest killer of avionics. So for the past few years I have kept a 0.5kg bag of silica gel in there, changed every time I fly (~ once a week). It is baked at +120C overnight to recycle it and I have about a dozen of the bags (~£5 each). Keeps everything dry and smelling fresh and like new
