Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE aircraft ( aircraft_id number, aircraft text, description text, max_gross_weight text, total_disk_area text, max_disk_loading text )
TABLE: CREATE TABLE pilot ( pilot_id number, name text, age number )
TABLE: CREATE TABLE airport ( airport_id number, airport_name text, total_passengers number, %_change_2007 text, international_passengers number, domestic_passengers number, transit_passengers number, aircraft_movements number, freight_metric_tonnes number )
TABLE: CREATE TABLE airport_aircraft ( id number, airport_id number, aircraft_id number )
TABLE: CREATE TABLE match ( round number, location text, country text, date text, fastest_qualifying text, winning_pilot text, winning_aircraft text )

### Question ###
List names of all pilot aged 30 or younger in descending alphabetical order.

### Accurate SQL ###

SELECT name FROM pilot WHERE age <= 30 ORDER BY name DESC