{"as_of":"2026-10-30","attribution":"FAA and NTSB data via eFlight Registry (https://eflight.com)","connections":[{"group":"Applies to","items":[{"count":3,"name":"Rolls-Royce 250-C28B","note":"","unit":"aircraft","url":"https://eflight.com/engines/rolls-royce-250-c28b#airworthiness"},{"count":16,"name":"Rolls-Royce 250-C47 series","note":"","unit":"aircraft","url":"https://eflight.com/engines/rolls-royce-250-c47-series#airworthiness"}],"relation":"applies to"},{"group":"System","items":[{"count":null,"name":"Engine","note":"","unit":"","url":"https://eflight.com/systems/engine"}],"relation":"about"},{"group":"More","items":[{"count":null,"name":"Every FAA order","note":"","unit":"","url":"https://eflight.com/directives"},{"count":null,"name":"Every aircraft system","note":"","unit":"","url":"https://eflight.com/systems"}],"relation":"see also"}],"graph":"https://eflight.com/graph","graph_index":"https://eflight.com/graph/index.json","license":"https://creativecommons.org/licenses/by/4.0/","node":{"effective":"1989-10-29","faa_document":"https://drs.faa.gov/browse/excelExternalWindow/6C9EF11D7DE7155386256840005A37F0.0001","id":"89-23-12","kind":"AD","name":"Airworthiness directive 89-23-12","published":"","subject":"Turbine Nozzle Assembly","system":"engine","type":"directive","url":"https://eflight.com/directives/89-23-12"},"source":"FAA Civil Aviation Registry, FAA airport file, NTSB accident database; assembled by eFlight Registry"}