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 ( name VARCHAR, aid VARCHAR )
TABLE: CREATE TABLE Certificate ( eid VARCHAR, aid VARCHAR )
TABLE: CREATE TABLE Employee ( eid VARCHAR, name VARCHAR )

### Question ###
Show names for all aircrafts of which John Williams has certificates.

### Accurate SQL ###

SELECT T3.name FROM Employee AS T1 JOIN Certificate AS T2 ON T1.eid = T2.eid JOIN Aircraft AS T3 ON T3.aid = T2.aid WHERE T1.name = "John Williams"