This morning someone sent me a link to a news story about 122 missing FAA investigator badges. If an accredited representative of the local aviation authority, which in the United States is the FAA, requests access to an airplane, I must accommodate him or her. The only way a crew could say "no, you can't ride along with us in the cockpit" is if all cockpit seats were already filled by persons essential to the flight. The FAA inspector can also go anywhere in the airport.
FAA inspectors may pose as ordinary passengers to evaluate airline compliance of passenger briefings. And then in cruise the inspector could present his credentials to the flight attendant and ask for cockpit access. I believe in this case he could be denied access if the airline SOPs forbade opening the cockpit door for any non-emergency reason during flight.
According to the article, FAA inspectors may also bypass airport security checkpoints. So here we have a scenario where someone can carry as much shampoo as they like onto any airplane they choose, and then ask to be taken directly to the cockpit and remain there for the duration of the flight. With their family-sized bottle of shampoo.
I'm thinking I might print that article out. If someone with an FAA (or Transport Canada or especially Civil Aviation Authority of Moldova) badge asks onto my airplane I will delay access until I can verify, through a published FAA telephone number, that the badge number is valid and that the person is supposed to be on my airplane. i crack myself p here, because as anyone who has ever called the FAA knows, no one seems to know what they are supposed to be doing, let alone what anyone else is supposed to be doing, and they rarely get back to you. I apologize to any affronted FAA people reading my blog, but truly to an outsider the system seems to be set up as a number of impenetrable shells, denying access to the people who know anything unless the caller is unusually persistent and lucky. If the badgeholder is legit and seriously concerned about the safety of my airplane, they shouldn't complain. If they are a legitimate FAA inspector looking for a free ride for personal reasons, they'll change their mind, and if they are an impostor ... hmm, maybe I'd better have a plan B.