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_name_83 (aircraft VARCHAR, retired VARCHAR, introduced VARCHAR)
### Question:
What aircraft was introduced in 2004 and has a retired of —?
### Answer:
SELECT aircraft FROM table_name_83 WHERE retired = "—" AND introduced = 2004