CREATE TABLE table_1338 ("Series #" FLOAT, "Season #" FLOAT, "Title" TEXT, "Directed by:" TEXT, "Written by:" TEXT, "Original air date" TEXT)

What is the original airdate when the season number is 4?
SELECT "Original air date" FROM table_1338 WHERE "Season #" = '4'
SELECT "Original air date" FROM "table_1338" WHERE "Season #" = '4'