SELECT aid FROM aircraft WHERE distance > 1000
What are the ids of all aircrafts that can cover a distance of more than 1000?
CREATE TABLE flight (
    flno number,
    origin text,
    destination text,
    distance number,
    departure_date time,
    arrival_date time,
    price number,
    aid number
)

CREATE TABLE certificate (
    eid number,
    aid number
)

CREATE TABLE employee (
    eid number,
    name text,
    salary number
)

CREATE TABLE aircraft (
    aid number,
    name text,
    distance number
)