Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_18712423_3 (original_air_date VARCHAR, directed_by VARCHAR, written_by VARCHAR)
### Question:
What is the original air date of the episode directed by Ian Barry and written by Philip Dalkin?
### Answer:
SELECT original_air_date FROM table_18712423_3 WHERE directed_by = "Ian Barry" AND written_by = "Philip Dalkin"