CREATE TABLE Aircraft (name VARCHAR(255), aid VARCHAR(255)); CREATE TABLE Employee (eid VARCHAR(255), name VARCHAR(255)); CREATE TABLE Certificate (eid VARCHAR(255), aid VARCHAR(255))
Show names for all aircrafts of which John Williams has certificates.
    
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"