{"as_of":"2026-10-05","attribution":"FAA and NTSB data via eFlight Registry (https://eflight.com)","connections":[{"group":"Applies to","items":[{"count":40,"name":"Pratt & Whitney Canada PT6A-15AG","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-canada-pt6a-15ag#airworthiness"},{"count":31,"name":"Pratt & Whitney Canada PT6A-27","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-canada-pt6a-27#airworthiness"},{"count":13,"name":"Pratt & Whitney Canada PT6A-28","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-canada-pt6a-28#airworthiness"},{"count":232,"name":"Pratt & Whitney Canada PT6A-34","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-canada-pt6a-34#airworthiness"},{"count":271,"name":"Pratt & Whitney Canada PT6A-34AG","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-canada-pt6a-34ag#airworthiness"},{"count":4,"name":"Pratt & Whitney Canada PT6A-36","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-canada-pt6a-36#airworthiness"},{"count":182,"name":"Pratt & Whitney Canada PT6A series","note":"","unit":"aircraft","url":"https://eflight.com/engines/pratt-whitney-canada-pt6a-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":"","faa_document":"https://drs.faa.gov/browse/excelExternalWindow/994D43AAE16A4BF68625790C005F46A7.0001","id":"2011-20-51","kind":"Emergency AD","name":"Airworthiness directive 2011-20-51","published":"","subject":"First stage reduction sun gears","system":"engine","type":"directive","url":"https://eflight.com/directives/2011-20-51"},"source":"FAA Civil Aviation Registry, FAA airport file, NTSB accident database; assembled by eFlight Registry"}