Originally Posted by
ToiletDuck
They could just make it part of the hiring requirements. You agree to have an active 1st class medical at all times. Could save them on insurance who knows. Technically no carrier could require an FO to have a first class at all but they all seem to while hiring.
Thay can and will require the first class to get hired...they can legally justify this because they want to hire FO's who will be able to upgrade eventually. This does make sense.
But once you're hired there's no reason to require a first class every six months for FO's. I think they usually want you to get a first class every year, but that's no big deal since it's the same exam and cost as a second...the doc just checks a different box.
In reality nobody issues (or asks for) a second class medical unless they already know they can't a hold a first. If you are in this situation you will generally be allowed to remain an FO forever (if you want to).