Robert M. Gary writes:

Most pilots would consider NORDO to be an emergency operation.

But some wouldn't, and it's perfectly legal.

All public use airports need communication. Flying into an airport (even a
very small one) without talking could certainly be considered careless
or reckless.

It's legal and safe if done correctly (at small airports). It may not be as
flexible or prudent as having a radio, but it's allowed and it isn't careless
or reckless.