Requirements for ground school/sim instrutor

[nearlylostlicence]

Dear All,

I need some basic info about instructing. I have a medical condition that might make me lose my medical in the near future. I would like to know if a sim instructor still needs a valid medical to work and what qualifications would be required (not talking about TRE) to do instruction only. I have about 12000 hrs total with a lot of experience on Airbus types. Alternatively, what would be required as qualifications to be a ground school teacher?

Thanks for any help.

Rgds,

Danny