Actually, I'm throwing the ball back in your court. I see that, in fulfilling your duties as MPs, you travel a great deal. So you're in a position to see the situation first-hand.
Sometimes, the impact can be felt on the planning end. For instance, I attended the Canada Games in Prince George last year. Obviously, the scheduled flight from Vancouver to Prince George is not designated as a bilingual flight, since not enough francophone passengers take the flight to warrant the airline providing French-language service on board. But the people at the airline realized that a significant number of francophones would be flying to Prince George for the Canada Games, so they took steps to ensure that flights from Vancouver to Prince George had bilingual flight attendants on board.
That example, as well as that of the Olympic Games, is evidence of the fact that strategic planning leads to success. Otherwise, the planning has failed, in my view, especially when we are talking about flights from Montreal to Quebec City, Toronto to Quebec City, or Montreal to Bathurst.
The first thing I would look at is whether any strategic planning was done to make sure flights had enough bilingual flight attendants on board. Another consideration would be the training available to unilingual flight attendants. The fact of the matter is you don't need to have studied at the Sorbonne to know what “verre d'eau” means. What's more, the flight attendant should realize that the person is asking to be served in French and should know what to do—such as ask a co-worker to step in—given that they can't communicate with the passenger, themselves.
Passengers have complained that unilingual flight attendants had absolutely no idea how to deal with someone asking to be served in French. No institution subject to the Official Languages Act has ever been required to make sure its entire workforce was bilingual. What matters, though, is that the institution has a system in place to make the service available and enough staff who can step in to assist when employees aren't able to provide that service, themselves.