Hi Bob.
My name is Ian Kim and I am preparing overseas conversion with your invaluable text books which is great.
I have Multi engine class rating and single engine class rating on my aeroplane commercial licence.
I have a question that I could not find the prompt answer from any regulations-CASR 61.
I am aware of that if I take the Multi engine flying test, the single engine class rating comes automatically but what if I take the Single Engine flying test, does the Multi engine class rating comes together?
If yes, could you give me the reference to look up?
If not, is there any particular reason?

Appreciate your time in advance.

Best Regards,
Ian Kim

Welcome to the forums Ian.

Class ratings are separate entities under the CASRs. Getting a single engine class rating cannot automatically authorise you to fly twins as there is the entire skillset associated with asymmetric flight which must be tested. The Manual of Standards (MOS) will outline the elements which need to be tested for the class ratings.

Interestingly I heard on the grapevine that even a multi class rating won't give you a single engine class rating automatically because the multi-engine class rating test doesn't deal with forced landings like a single engine class rating test has to.

Also, since a multi-engine class rating can only be attached to a licence such as a PPL, CPL, or ATPL (see CASR 61.750 (2) ), it stands to reason you must have achieved that licence with a single engined aeroplane class rating.

As for where to find the info, the CASRs...
CASR 61.375 (4) -> Having a multi rating covers you for flying a single
CASR 61.735 -> Class Ratings information
CASR 61.750 (2) -> Mutli needs to be attached to a licence PPL or above.

Where to find the justification for it? Ask CASA. Guessing at the logic of Part 61 is a task best left to those who created the mess.

This is just my 2c on your question. CASA will give the definitive answer.

Cheers,

Rich