{"as_of":"2026-11-06","attribution":"FAA and NTSB data via eFlight Registry (https://eflight.com)","connections":[{"group":"Applies to","items":[{"count":34,"name":"Sikorsky Aircraft Corp S-76","note":"","unit":"registered","url":"https://eflight.com/models/sikorsky-aircraft-corp/s-76#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":"1981-09-21","faa_document":"https://drs.faa.gov/browse/excelExternalWindow/22DADAAC3D3C869686256A4E0044A0D3.0001","id":"81-07-51 R1","kind":"AD","name":"Airworthiness directive 81-07-51 R1","published":"","subject":"Main Rotor Spindles","system":"rotorcraft","type":"directive","url":"https://eflight.com/directives/81-07-51 R1"},"source":"FAA Civil Aviation Registry, FAA airport file, NTSB accident database; assembled by eFlight Registry"}