{"as_of":"2026-11-09","attribution":"FAA and NTSB data via eFlight Registry (https://eflight.com)","connections":[{"group":"Design","items":[{"count":825,"name":"Sikorsky","note":"","unit":"aircraft on the register","url":"https://eflight.com/makers/sikorsky"},{"count":9,"name":"Sikorsky S-55B","note":"","unit":"registered","url":"https://eflight.com/models/sikorsky/s-55?variant=S-55B"},{"count":3,"name":"Sikorsky S-55","note":"","unit":"registered","url":"https://eflight.com/models/sikorsky/s-55?variant=S-55"},{"count":3,"name":"Sikorsky S55B","note":"","unit":"registered","url":"https://eflight.com/models/sikorsky/s-55?variant=S55B"},{"count":null,"name":"Type certificate 1H4","note":"held by California Helicopter Airways INC","unit":"","url":""},{"count":null,"name":"Built of aluminium","note":"","unit":"","url":"https://eflight.com/materials/aluminium"}],"relation":"made by"},{"group":"Engines","items":[{"count":4,"name":"Wright C7BA series","note":"800 hp","unit":"of these aircraft","url":"https://eflight.com/engines/wright-c7ba-series"},{"count":3,"name":"AiResearch (Honeywell) TSE331 series","note":"800 hp","unit":"of these aircraft","url":"https://eflight.com/engines/airesearch-honeywell-tse331-series"},{"count":2,"name":"Wright R-1300 series","note":"700 hp","unit":"of these aircraft","url":"https://eflight.com/engines/wright-r-1300-series"},{"count":1,"name":"Wright R-1300-3D","note":"800 hp","unit":"of these aircraft","url":"https://eflight.com/engines/wright-r-1300-3d"},{"count":1,"name":"Pratt & Whitney R1340 series","note":"600 hp","unit":"of these aircraft","url":"https://eflight.com/engines/pratt-whitney-r1340-series"}],"relation":"powered by"},{"group":"Where they are","items":[{"count":9,"name":"Kentucky","note":"","unit":"of these aircraft","url":"https://eflight.com/states/KY"},{"count":1,"name":"Washington","note":"","unit":"of these aircraft","url":"https://eflight.com/states/WA"},{"count":1,"name":"Oregon","note":"","unit":"of these aircraft","url":"https://eflight.com/states/OR"},{"count":1,"name":"Oklahoma","note":"","unit":"of these aircraft","url":"https://eflight.com/states/OK"},{"count":1,"name":"New Jersey","note":"","unit":"of these aircraft","url":"https://eflight.com/states/NJ"}],"relation":"registered in"},{"group":"Biggest operators","items":[{"count":9,"name":"Sierra Aeronautics LLC","note":"","unit":"of these aircraft","url":"https://eflight.com/fleets/sierra-aeronautics-llc"},{"count":1,"name":"N2302F LLC","note":"","unit":"of these aircraft","url":"https://eflight.com/search?q=N2302F LLC"}],"relation":"owned by"},{"group":"Record","items":[{"count":15,"name":"NTSB accidents and incidents involving the S-55","note":"2 fatal","unit":"cases since 1982","url":"https://eflight.com/models/sikorsky/s-55#accidents"}],"relation":"involved in"},{"group":"Airworthiness","items":[{"count":19,"name":"FAA orders naming the S-55","note":"","unit":"airworthiness directives","url":"https://eflight.com/models/sikorsky/s-55#airworthiness"},{"count":3,"name":"Failure reports filed on the S-55","note":"","unit":"reports since 1995","url":"https://eflight.com/models/sikorsky/s-55#airworthiness"},{"count":18,"name":"Approved modifications for the S-55","note":"","unit":"supplemental type certificates","url":"https://eflight.com/models/sikorsky/s-55#airworthiness"}],"relation":"subject to"},{"group":"Analytics","items":[{"count":null,"name":"Accidents by model, with rates per thousand registered","note":"","unit":"","url":"https://eflight.com/analytics/accidents-by-model"},{"count":null,"name":"The fleet by kind, state and age","note":"","unit":"","url":"https://eflight.com/analytics/fleet"},{"count":null,"name":"Biggest makers and model families","note":"","unit":"","url":"https://eflight.com/analytics/makers"}],"relation":"compared in"}],"graph":"https://eflight.com/graph","graph_index":"https://eflight.com/graph/index.json","license":"https://creativecommons.org/licenses/by/4.0/","node":{"built_of":{"material":"aluminium","name":"aluminium","note":null},"id":"sikorsky/s-55","name":"Sikorsky S-55","registered":15,"type":"model","url":"https://eflight.com/models/sikorsky/s-55","versions":3},"source":"FAA Civil Aviation Registry, FAA airport file, NTSB accident database; assembled by eFlight Registry"}
