What date did the episode that was written by Fintan Ryan originally air?
CREATE TABLE "table1_27218002_2" (
  "episode_num" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "originalairdate" text,
  "ratings" text
);
SELECT "originalairdate" FROM "table1_27218002_2" WHERE "written_by"='Fintan Ryan';