"Barry" wrote in message ...
Why do some airports with an instrument approach (e.g. HIE) lack
a surface Class E to protect the approach?

In fact this is the case for the great majority of non-towered airports.

Often, though, the only available approaches have an MDA that's still within
Class E. In that case, there's no problem seeing and avoiding VFR aircraft
in the uncontrolled space underneath. Not so at HIE, however.

--Gary