When the duration was 11 min, 34 sec, what was the feathered (Fxx)?
CREATE TABLE "list_of_test_flights" (
  "flight_designation" text,
  "date" text,
  "duration" text,
  "pilot_co_pilot" text,
  "feathered_fxx" text
);
SELECT "feathered_fxx" FROM "list_of_test_flights" WHERE "duration"='11 min, 34 sec';