About: http://webisa.webdatacommons.org/50749712

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	The basic (non)answer is because either no engine or other aircraft part survived with identifiable catalog numbers on them AND the government refuses Freedom of Information Act Requests for what numbers they may, in fact, have.
http://www.w3.org/ns/prov#wasQuotedFrom	pilotsfor911truth.org