What is the {flag carrier} for {operator} of {Airbus A330}
What carriers use the Airbus A330?
Which carriers operate the Airbus A330?
SELECT DISTINCT ?i WHERE { resource:Airbus_A330 property:operator ?i . ?i rdf:type ontology:flag_carrier }
select distinct ?obj where { ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q6478> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P137> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj . ?obj <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q721639> } 
 select distinct ?obj where { wd:Q6478 wdt:P137 ?obj . ?obj wdt:P31 wd:Q721639 } 
Air Greenland Qantas