What are the names of the aircraft that the least people are certified to fly?
CREATE TABLE flight (
    flno number,
    origin text,
    destination text,
    distance number,
    departure_date time,
    arrival_date time,
    price number,
    aid number
)

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

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

CREATE TABLE certificate (
    eid number,
    aid number
)
SELECT T2.name FROM certificate AS T1 JOIN aircraft AS T2 ON T2.aid = T1.aid GROUP BY T1.aid ORDER BY COUNT(*) DESC LIMIT 1
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What are the names of the aircraft that the least people are certified to fly? ### Input: CREATE TABLE flight (
    flno number,
    origin text,
    destination text,
    distance number,
    departure_date time,
    arrival_date time,
    price number,
    aid number
)

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

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

CREATE TABLE certificate (
    eid number,
    aid number
) ### Response: SELECT T2.name FROM certificate AS T1 JOIN aircraft AS T2 ON T2.aid = T1.aid GROUP BY T1.aid ORDER BY COUNT(*) DESC LIMIT 1