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_15637071_1 (commenced_operations VARCHAR, headquarters VARCHAR)

### Question ###
Which year did the Angeles City based airline begin operations?

### Accurate SQL ###

SELECT commenced_operations FROM table_15637071_1 WHERE headquarters = "Angeles City"