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_name_4 (callsign VARCHAR, iata VARCHAR)
### Question:
Which Callsign has an IATA of tr?
### Answer:
SELECT callsign FROM table_name_4 WHERE iata = "tr"