{"as_of":"2026-10-07","attribution":"FAA and NTSB data via eFlight Registry (https://eflight.com)","connections":[{"group":"Applies to","items":[{"count":421,"name":"Robinson R66","note":"","unit":"registered","url":"https://eflight.com/models/robinson/r66#airworthiness"}],"relation":"applies to"},{"group":"System","items":[{"count":null,"name":"Rotorcraft systems","note":"","unit":"","url":"https://eflight.com/systems/rotorcraft"}],"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":"2021-04-12","faa_document":"https://drs.faa.gov/browse/excelExternalWindow/B6F46D51A7C9FB7F86258692005C1118.0001","id":"2021-04-12","kind":"AD","name":"Airworthiness directive 2021-04-12","published":"2021-03-08","subject":"Tail Rotor Drive Shaft","system":"rotorcraft","type":"directive","url":"https://eflight.com/directives/2021-04-12"},"source":"FAA Civil Aviation Registry, FAA airport file, NTSB accident database; assembled by eFlight Registry"}