That's a good link, thanks.

So, налетать means 'to fly onto/up against'. That makes sense.
I couldn't see anything about the prefix making it perfective, in fact 'налететь' is listed as the perfective. This is backed up by this entry here: https://en.wiktionary.org/wiki/%D0%B...B0%D1%82%D1%8C

Maybe the website I took the sentence from made a mistake? Or is it possible that the Russian sentence translates to 'He flew (maybe back and forth) for 5000 miles', but they didn't make that clear?

Also, If I had rewritten it as
Он залетел 5000 миль.
Он пролетел 5000 миль.
Would either/both of these sentences mean 'He flew 5000 miles'

Thanks for the reply and link.