Although I think the billboard idea is good ... any publicity is good publicity ... I think the message might be lost on the average punter.
"When you board a QANTAS flight, you expect a QANTAS pilot"
My first thought, and I'm in the Industry, was ... yeah, of course, what do you think you're going to get, a British Airways pilot?"
I think your subtle definition of a "Qantas Pilot" might be lost on most folk. I think they'd scratch their heads and the only way of clarifying it would be to do some research ... which most won't. Isn't an Indonesian, trained in Nigeria, employed by Qantas and based in Shanghai, still a Qantas Pilot?
Perhaps ... "you expect an Australian pilot" might have been better (although probably not PC enough)