can you direct me to where in the regs it decrees that manufacturers' SBs are mandatory? I can't find it. Not trying to shoot the messenger, in fact I would love it if (as the registered operator responsible for the airworthiness of the aircraft) CASA communicated directly with me, rather than telling (should at read threatening?) the maintenance providers what they should be telling me. Puts the shops in a difficult position, I realise. Show me the reg that determines this stance, that is what I need.