What is the original air date of the episode titled "Pilot"?
CREATE TABLE "table1_22815870_1" (
  "series_num" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "prod_code" real
);
SELECT "original_air_date" FROM "table1_22815870_1" WHERE "title"='\"Pilot\"';