Stealth Pilot wrote:

log the important hours, not the useless stuff.

I'd recommend logging the time. If nothing else, this provides a backup to
the entry in your friend's log. It may also be something you ask later:
when have I been a safety pilot, and for whom?

This is one of the things I learned while diving: logging is as much for the
fun of it as for the tracking of numbers and such.

just be happy in the thought that one of your mates thought enough of
you to invite you along. you might need the same assistance at the
other end of your flying life yourself.

Sigh I know what you mean. I remember a rental checkout once with a CFI
that had lost her medical (for a very serious and ongoing problem,
unfortunately, esp. given that she was barely half my age). I was happy to
be part of the team keeping her in the air. I think I may actually have
rented there only once, but that's the checkout that's still most with me.

A CFI friend recently lost his medical. I need to check on what I can do
with him (dual commercial XCs, perhaps), and I'm sure I'm not the only one
with this plan in mind.

- Andrew