CREATE TABLE "echo_i_class_significant_dates" (
  "shipyard" text,
  "laid_down" text,
  "launched" text,
  "commissioned" text,
  "fleet" text,
  "status" text
);

Question: Which fleet launched on July 30, 1961?
SQL: SELECT "fleet" FROM "echo_i_class_significant_dates" WHERE "launched"='july 30, 1961';

Question: Which shipyard has a fleet that was laid down on April 21, 1962?
SQL: SELECT "shipyard" FROM "echo_i_class_significant_dates" WHERE "laid_down"='april 21, 1962';

Question: What is the status of the fleet that was commissioned on July 28, 1963?
SQL: SELECT "status" FROM "echo_i_class_significant_dates" WHERE "commissioned"='july 28, 1963';