You’re mixing up the Fermi paradox and the Drake equation.
Assuming you meant the Drake equation, more than half of the variables we have absolutely no statistical basis to decide on a fraction. Obviously they are non-zero, but they could be extremely improbable. We only have one example of intelligent life developing radio communications. Any estimate of a statistical likelihood of that using Earth as an example is meaningless without other examples.
Some pessimistic estimates give solutions as small 9.1 x 10^-13 which indicates we would be alone.
The Fermi Paradox riffs on the optimistic answer to Drake’s Equation. If other intelligent life is a certainty, why haven’t we found them yet?
This is not true at all. You’re right that planes aren’t like cars, but airlines absolutely do their own maintenance. The maintenance program is initially provided by Boeing and modified by the airline based on statistical monitoring of issues.