AA to *A before passport control?
 

I am flying from YOW -> FRA via AC. A colleague is flying ORD -> FRA via AA. We both arrive about the same time. Is it possible for him to meet me at near my arrival gate (before passport control), or do we need to meet in the public area?

Totaly depends on the arrival concourse. Needs to be the same.
From my experience both AA and AC arrive in Terminal 1 Concourse B, in that case you should be fine.

Do you share a connection flight out of FRA?

Not via air. We are taking DB to Nürnberg, hence the hope to meet somewhere reasonable (that and lounge access; I'm *G, and have always found LH happy to let arriving pax use the Senator lounge to grab a shower)

Yes, but your guest normaly needs to have an *A BP, as this lounge is always overloaded, you need to be really lucky to bring your AA flying guest in... But who knows.

Isn't there an admirals club landside? maybe your friend can take you in?

That is a good thought, however my friend does not have status (on any airline). This is his first time traveling to Europe and he does very little travel elsewhere.

The whole Frankfurt airport is connected on the non-schengen side, although for many areas you need to convince FRAport personal to let you through a security check by presenting a BP or a status card for lounges inside. AC arrives in T1B and AA in T1C. The main C area is outside of any security control, so you easily walk over to the C gates following the signs and meet with your friend before the T1C immigration lines. It would be much easier to simply meet outside of immigration, though..