Can we use ECI coordinates for an airplane? It is taught for navigation systems (like an airplane) on Earth we us ECEF (earth-centered, earth-fixed) and for space systems (like a satellite) we use ECI (earth-centered inertial). But why is ECEF exclusively used for navigation vehicles on Earth and ECI is exclusively used for satellites and spacecraft in space?  Why can't we use ECI for an airplane to observed another perspective?
The basic reason is the goal in navigation.  For an airplane it is to deliver the aircraft to a particular destination on the earth's surface, potentially also avoiding certain areas fixed to the earth's surface.

If you do all your navigation calculations in ECI, you then have to keep track of the earth's rotation to translate that to a point on the surface.  If you do all the navigation in ECEF, then that translation is unnecessary.

Both methods are mathematically valid (for ECEF, you have to have some method of removing or ignoring the non-inertial frame effects like Coriolis; for ECI, you have to keep track of earth rotation).  I don't have any direct evidence, but I suspect that since ECI was not an option historically, the current solutions are robust and no one is looking to create a radically different method for unknown benefit.