what kind of failure caused 1958 london vickers viking accident's accident?
Entity
m.0742yy
Pilot error
class entity
aviation.accident_type m.0bh71lj
aviation.accident_type aviation.airliner_accident
Aircraft accident type 1958 London Vickers Viking accident
none none
aviation.accident_type.aircraft_accidents_of_this_type
Aircraft accidents of this type
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX : <http://rdf.freebase.com/ns/> 
SELECT (?x0 AS ?value) WHERE {
SELECT DISTINCT ?x0  WHERE { 
?x0 :type.object.type :aviation.accident_type . 
VALUES ?x1 { :m.0bh71lj } 
?x0 :aviation.accident_type.aircraft_accidents_of_this_type ?x1 . 
FILTER ( ?x0 != ?x1  )
}
}
(AND aviation.accident_type (JOIN aviation.accident_type.aircraft_accidents_of_this_type m.0bh71lj))