human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Series #, Title, Directed by, Written by, Original air date, Production code, U.S. viewers (million)
###Question: What is the original air date when the u.s. viewers in millions was 5.39?
gpt
SELECT Original air date FROM table WHERE U.S. viewers (million) = 5.39