About: http://webisa.webdatacommons.org/71079011

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Yes, 400Hz systems are mainly used in aircrafts and ground systems at airports.
http://www.w3.org/ns/prov#wasQuotedFrom	theiet.org