CREATE TABLE table_27790959_1 (original_air_date VARCHAR, us_viewers__million_ VARCHAR)

What was the original air date of the episode that had 5.42 million viewers?
SELECT original_air_date FROM table_27790959_1 WHERE us_viewers__million_ = "5.42"
SELECT "original_air_date" FROM "table_27790959_1" WHERE "5.42" = "us_viewers__million_"