The ATSB acknowledges that CASA addressed the regulatory component of the reporter's concern. The ATSB requested a further response from CASA to specifically address the reporter's ultimate concern that CASR Part 23 normal category aircraft (in particular those used for ab-initio flight training) allows operators to legally operate aircraft with an inoperative aural stall warning system.' CASA reiterated the current requirements for aural stall warnings / stall warnings in general, and CASR Part 23, are in alignment with international…