{"as_of":"2026-10-23","attribution":"FAA and NTSB data via eFlight Registry (https://eflight.com)","connections":[{"group":"Model families","items":[{"count":108,"name":"Md Helicopters Inc 369","note":"","unit":"registered","url":"https://eflight.com/models/md-helicopters-inc/369"},{"count":14,"name":"Md Helicopters Inc 500","note":"","unit":"registered","url":"https://eflight.com/models/md-helicopters-inc/500"},{"count":12,"name":"Md Helicopters Inc 600","note":"","unit":"registered","url":"https://eflight.com/models/md-helicopters-inc/600"},{"count":11,"name":"Md Helicopters Inc MD 900","note":"","unit":"registered","url":"https://eflight.com/models/md-helicopters-inc/md-900"}],"relation":"makes"},{"group":"Engines","items":[{"count":44,"name":"Rolls-Royce 250-C30","note":"650 hp","unit":"of these aircraft","url":"https://eflight.com/engines/rolls-royce-250-c30"},{"count":24,"name":"Rolls-Royce 250-C20B","note":"420 hp","unit":"of these aircraft","url":"https://eflight.com/engines/rolls-royce-250-c20b"},{"count":17,"name":"Rolls-Royce 250-C20R/2","note":"450 hp","unit":"of these aircraft","url":"https://eflight.com/engines/rolls-royce-250-c20r-2"},{"count":10,"name":"Allison (Rolls-Royce) 250-C20 series","note":"420 hp","unit":"of these aircraft","url":"https://eflight.com/engines/allison-rolls-royce-250-c20-series"},{"count":8,"name":"Rolls-Royce 250-C47M","note":"650 hp","unit":"of these aircraft","url":"https://eflight.com/engines/rolls-royce-250-c47m"}],"relation":"powered by"},{"group":"Type certificates","items":[{"count":null,"name":"MD Helicopters INC (Mdhi)","note":"holds the FAA type certificates","unit":"","url":""}],"relation":"held by"},{"group":"Where they are","items":[{"count":15,"name":"Delaware","note":"","unit":"of these aircraft","url":"https://eflight.com/states/DE"},{"count":14,"name":"Texas","note":"","unit":"of these aircraft","url":"https://eflight.com/states/TX"},{"count":14,"name":"Oregon","note":"","unit":"of these aircraft","url":"https://eflight.com/states/OR"},{"count":11,"name":"California","note":"","unit":"of these aircraft","url":"https://eflight.com/states/CA"},{"count":10,"name":"Utah","note":"","unit":"of these aircraft","url":"https://eflight.com/states/UT"}],"relation":"registered in"},{"group":"Biggest operators","items":[{"count":6,"name":"Usda Aphis Ws Atoc","note":"","unit":"of these aircraft","url":"https://eflight.com/fleets/usda-aphis-ws-atoc"},{"count":5,"name":"Winco INC","note":"","unit":"of these aircraft","url":"https://eflight.com/fleets/winco-inc"},{"count":5,"name":"City Of Houston","note":"","unit":"of these aircraft","url":"https://eflight.com/fleets/city-of-houston"},{"count":4,"name":"Tennessee Valley Authority","note":"","unit":"of these aircraft","url":"https://eflight.com/fleets/tennessee-valley-authority"},{"count":4,"name":"Heliservice LLC","note":"","unit":"of these aircraft","url":"https://eflight.com/fleets/heliservice-llc"}],"relation":"owned by"},{"group":"Record","items":[{"count":13,"name":"NTSB accidents and incidents involving Md Helicopters Inc aircraft","note":"as the NTSB spells the maker's name","unit":"cases since 1982","url":"https://eflight.com/analytics/accidents-by-model"}],"relation":"involved in"},{"group":"Analytics","items":[{"count":null,"name":"Biggest makers and model families","note":"","unit":"","url":"https://eflight.com/analytics/makers"},{"count":null,"name":"Accidents by model and by maker","note":"","unit":"","url":"https://eflight.com/analytics/accidents-by-model"}],"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":{"id":"md-helicopters-inc","name":"Md Helicopters Inc","registered":145,"type":"maker","url":"https://eflight.com/makers/md-helicopters-inc"},"source":"FAA Civil Aviation Registry, FAA airport file, NTSB accident database; assembled by eFlight Registry"}