SpottyFish,
The regulations don’t require ICUS to be "approved" by CASA.
However in the case of non-private operations where the ICUS is conducted under an AOC, the operators operations manual should say how an operator conducts all their operations, including ICUS.
Operations manuals are not "approved" by CASA, they are accepted, I understand this legal two step is so CASA is not liable for their contents.
It is possible to conduct ICUS under any operation, including private operations, in any aircraft type, e.g. C150 to B747. In the case of Qantas, F/O's do ICUS in the RHS without a tiller in most aircraft.
In my experience with CASA, some of the interpretation of the rules comes from previous background, their strengths would lie in where they have achieved most of their experience from.
Few FOIs for example would come from a background of flying above 5700kg aircraft in private operations, so I believe their natural tendency would be to apply their previous knowledge to the new situation of people doing say ICUS on a Falcon 900 in a private operation, hence comments like "have received approval to handle emergency situation from the non command seat".
ICUS is not pseudo training, the person receiving ICUS should have all the required ratings and endorsements to fly that aircraft in command. In my view if the person undergoing ICUS is not competent to fly the aircraft in command, they should go through a course of training, i.e. instruction, not ICUS.
I have always seen ICUS as a method for someone to go from being “safe and competent” to being efficient, being a “good operator” with some line experience on type.
