{"as_of":"2026-11-06","attribution":"FAA and NTSB data via eFlight Registry (https://eflight.com)","connections":[{"group":"System","items":[{"count":null,"name":"Propeller","note":"","unit":"","url":"https://eflight.com/systems/propeller"}],"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":"1988-10-31","faa_document":"https://drs.faa.gov/browse/excelExternalWindow/CF75D08846D9108886256974005FC4E7.0001","id":"88-20-08","kind":"AD","name":"Airworthiness directive 88-20-08","published":"","subject":"Retaining Rings","system":"propeller","type":"directive","url":"https://eflight.com/directives/88-20-08"},"source":"FAA Civil Aviation Registry, FAA airport file, NTSB accident database; assembled by eFlight Registry"}