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"
### Context: CREATE TABLE table_13605170_2 (retired VARCHAR, aircraft_type VARCHAR) ### Question: how many Curtiss XBTC aircraft are retired? ### Answer: SELECT COUNT(retired) FROM table_13605170_2 WHERE aircraft_type = "Curtiss XBTC"