Thanks
itsresidual 
So will all four masks fed from the same PSU start delivering oxygen from a single 'candle' the moment the first is pulled i.e. is it four masks/lanyards rigged to pull the same pin on one candle/PSU over each three seats?
Oh and don't need to be an expert to answer
Big Burd. I can tell you the problem was that an emergency occurred, and we don't yet know how or why. Fascinating how each of us with different takes on the matter can enlighten one another, ain't it?
