Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_15637071_1 (commenced_operations VARCHAR, headquarters VARCHAR)
### Question:
Which year did the Angeles City based airline begin operations?
### Answer:
SELECT commenced_operations FROM table_15637071_1 WHERE headquarters = "Angeles City"