Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_21634 ( "Series #" real, "Season #" real, "Title" text, "Directed by" text, "Written by" text, "Original air date" text )

### Question ###
On which dates did the episodes directed by TR Babu Subramaniam air?

### Accurate SQL ###

SELECT "Original air date" FROM table_21634 WHERE "Directed by" = 'TR Babu Subramaniam'