user: Question: When did episode number 6 air?
Columns: ['Episode no.', 'Airdate', 'Viewers', 'BBC Three weekly ranking', 'Cable rank']
Types: ['real', 'text', 'real', 'real', 'real']
Sample row: [1.0, '21 October 2010', 956000.0, 3.0, 10.0]
SQL:

assistant: SELECT "Airdate" FROM "Table" WHERE "Episode no." = 6.0;