A question for those operating in and out of the US
 

As a pilot of a mainland European airline we have long been used to the flight deck access visit limitations in US and UK airspace. Our management announced yesterday that flight deck access at ANY stage of the flight can only be granted to operating crew on the Gendec. So if we have a uniformed crew member from our company is on board they can not visit us mid Ocean. No documentation given to support this OUTSIDE US airspace policy.....can anyone point me to it? Thanks in advance.

I’m not sure I’m understating your question but according to the FAR’s the strictest set of regs apply.
So N-reg operating on a US based certificate over international waters or foreign territories the no access policy applies as that’s the strictest.
What am I missing here.

At the risk of being Devil's advocate - does the company actually need any external documention to support this? It might be an unpopular rule change but fundamentally isn't this simply a case of it's their train set and somebody in HQ has decided to put additional controls on access to the flight deck.

Indeed. They don't have to justify themselves...

FARs
 

The notice advised it was a US mandated change so if B2 says FARs permit no access then it appears We are just falling in line with that. The question was one of legality not whose train set it is.

I remember we frequently pax'd in uniform on the GD, mainly for ease of immigration at destination, but it also allowed for 'no problem' jump seating and flight deck visits. Once on the GD you are crew, even if supernumerary.