how many Curtiss XBTC aircraft are retired?
CREATE TABLE table_13605170_2 (retired VARCHAR, aircraft_type VARCHAR)
SELECT COUNT(retired) FROM table_13605170_2 WHERE aircraft_type = "Curtiss XBTC"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_13605170_2 (retired VARCHAR, aircraft_type VARCHAR) Question: how many Curtiss XBTC aircraft are retired? [/INST] SELECT COUNT(retired) FROM table_13605170_2 WHERE aircraft_type = "Curtiss XBTC" </s>