{"as_of":"2026-10-07","attribution":"FAA and NTSB data via eFlight Registry (https://eflight.com)","connections":[{"group":"Applies to","items":[{"count":1,"name":"Pratt & Whitney JT9D-59A","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-jt9d-59a#airworthiness"},{"count":4,"name":"Pratt & Whitney JT9D-7R4D","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-jt9d-7r4d#airworthiness"},{"count":1,"name":"Pratt & Whitney JT9D-7R4E","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-jt9d-7r4e#airworthiness"},{"count":13,"name":"Pratt & Whitney JT9D series","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-jt9d-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":"2000-01-18","faa_document":"https://drs.faa.gov/browse/excelExternalWindow/1D87982E566996FC862568800050CAF0.0001","id":"98-21-22 R1","kind":"AD","name":"Airworthiness directive 98-21-22 R1","published":"1999-11-19","subject":"High Pressure Compressor Disks","system":"engine","type":"directive","url":"https://eflight.com/directives/98-21-22 R1"},"source":"FAA Civil Aviation Registry, FAA airport file, NTSB accident database; assembled by eFlight Registry"}