Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_191105_3 (first_aired VARCHAR, subject VARCHAR)

### Question ###
If skeletal system is the subject when was it first aired?

### Accurate SQL ###

SELECT first_aired FROM table_191105_3 WHERE subject = "Skeletal system"