Hello. I have a fellow pilot at the crashpad who is updating his logbook and forgot a flight and then logged subsequent flights. How would you address this situation?

If the time is not necessary to show currency, I would simply skip logging it.

We're flying Caravans part 135. He needs the ME time for the regionals. Haha

You could add it in wherever and just note in the comments that it was a late entry. If you're trying to keep a pristine logbook, and don't need the time badly, you could skip it.

Put it in the next blank log entry and put the date the flight actually happened. Then continue logging everything else as normal. Nobody cares and it's easy enough to explain anyway. We've all been there where every hour counted.

Also, if he every switches to an electronic logbook it will end up in sequential order anyway.

Back when I kept a paper logbook (when the world was black and white, and smart phones only had 3G) I would just write it on the most recent page, with the correct date. It's not sloppy at all, just an out-of-order entry. If you're anal, you can go back to the page it was on and write a note that says "see page 7 for entry added out of order").

Short answer: who cares?

I know people who forgot to log an entire year. Or ten.

As others noted, write the missing flight in on the next line. It makes no difference at all so long as it wasn't necessary to meet currency (which is the only legal reason to keep the log at all). Who cares if the date is out of order? I know a number of pilots who make a single entry every year, or every month. Some who are more fastidious, but if he's concerned about how the log looks at an interview, then keep it neat and tidy and nobody will give it a second thought.

After twelve years and !0,000 hours all I had to prove was that was I was in compliance of flight time/ duty time regs. Kept the last 30 days of releases to prove compliance though company had the same records. Under scrutiny of booth FAA and NTSB I claimed 20,000 plus hours and no demand for evidence though I had even more