{"as_of":"2026-10-05","attribution":"FAA and NTSB data via eFlight Registry (https://eflight.com)","connections":[{"group":"Model families","items":[{"count":6247,"name":"Mooney M-20","note":"The first M20 and M20A (1955 to 1960) had wooden wings and tails; all later ones are metal.","unit":"registered","url":"https://eflight.com/models/mooney/m-20"},{"count":1933,"name":"Robinson R44","note":"A welded steel-tube frame under aluminium and fibreglass skins; metal rotor blades.","unit":"registered","url":"https://eflight.com/models/robinson/r44"},{"count":817,"name":"Robinson R22","note":"A welded steel-tube frame under aluminium and fibreglass skins; metal rotor blades.","unit":"registered","url":"https://eflight.com/models/robinson/r22"},{"count":683,"name":"Air Tractor Inc AT-802","note":"A crop sprayer and fire bomber: welded steel-tube fuselage under aluminium skins.","unit":"registered","url":"https://eflight.com/models/air-tractor-inc/at-802"},{"count":502,"name":"Air Tractor Inc AT-502","note":"A crop sprayer: welded steel-tube fuselage under aluminium skins, aluminium wings.","unit":"registered","url":"https://eflight.com/models/air-tractor-inc/at-502"},{"count":477,"name":"Bell 47","note":"An open welded steel-tube frame with a plexiglass bubble.","unit":"registered","url":"https://eflight.com/models/bell/47"},{"count":421,"name":"Robinson R66","note":"A welded steel-tube frame under aluminium and fibreglass skins; metal rotor blades.","unit":"registered","url":"https://eflight.com/models/robinson/r66"},{"count":275,"name":"Schweizer SGS 2 gliders (2-33 and 2-32)","note":"The 2-33 trainer: steel-tube fuselage under fabric, aluminium wings.","unit":"registered","url":"https://eflight.com/models/schweizer/sgs-2"},{"count":246,"name":"Air Tractor Inc AT-602","note":"A crop sprayer: welded steel-tube fuselage under aluminium skins, aluminium wings.","unit":"registered","url":"https://eflight.com/models/air-tractor-inc/at-602"},{"count":244,"name":"Ayres Corporation S-2","note":"The Thrush crop sprayer.","unit":"registered","url":"https://eflight.com/models/ayres-corporation/s-2"},{"count":217,"name":"Hiller UH-12","note":"","unit":"registered","url":"https://eflight.com/models/hiller/uh-12"},{"count":212,"name":"Schweizer 269 300 series helicopters","note":"An open steel-tube frame.","unit":"registered","url":"https://eflight.com/models/schweizer/269"}],"relation":"used in"},{"group":"Makers","items":[{"count":5396,"name":"Mooney","note":"","unit":"aircraft on the register","url":"https://eflight.com/makers/mooney"},{"count":null,"name":"Robinson","note":"","unit":"","url":"https://eflight.com/makers/robinson"},{"count":1810,"name":"Air Tractor Inc","note":"","unit":"aircraft on the register","url":"https://eflight.com/makers/air-tractor-inc"},{"count":1187,"name":"Schweizer","note":"","unit":"aircraft on the register","url":"https://eflight.com/makers/schweizer"},{"count":3085,"name":"Bell","note":"","unit":"aircraft on the register","url":"https://eflight.com/makers/bell"},{"count":244,"name":"Ayres Corporation","note":"","unit":"aircraft on the register","url":"https://eflight.com/makers/ayres-corporation"},{"count":242,"name":"Hiller","note":"","unit":"aircraft on the register","url":"https://eflight.com/makers/hiller"},{"count":385,"name":"Hughes","note":"","unit":"aircraft on the register","url":"https://eflight.com/makers/hughes"}],"relation":"built by"},{"group":"Other materials","items":[{"count":137,"name":"Aluminium","note":"","unit":"model families","url":"https://eflight.com/materials/aluminium"},{"count":30,"name":"Steel tube and fabric","note":"","unit":"model families","url":"https://eflight.com/materials/steel-fabric"},{"count":30,"name":"Aluminium with composite parts","note":"","unit":"model families","url":"https://eflight.com/materials/aluminium-composite"},{"count":21,"name":"Composite","note":"","unit":"model families","url":"https://eflight.com/materials/composite"},{"count":21,"name":"Carbon fibre and plastic","note":"","unit":"model families","url":"https://eflight.com/materials/drone-composite"},{"count":9,"name":"Steel tube, wood and fabric","note":"","unit":"model families","url":"https://eflight.com/materials/steel-wood-fabric"},{"count":3,"name":"Fabric and wicker","note":"","unit":"model families","url":"https://eflight.com/materials/balloon"},{"count":1,"name":"Fabric wing and steel frame","note":"","unit":"model families","url":"https://eflight.com/materials/parachute"}],"relation":"compared with"}],"graph":"https://eflight.com/graph","graph_index":"https://eflight.com/graph/index.json","license":"https://creativecommons.org/licenses/by/4.0/","node":{"aircraft_registered":12797,"description":"A welded steel-tube frame carries the loads, with aluminium (and some fibreglass) skins over it.","id":"steel-aluminium","model_families":15,"name":"Steel tube and aluminium","source":"hand-written by eFlight Registry from published descriptions; the FAA type certificate data sheet is the authority for any one model","type":"material","url":"https://eflight.com/materials/steel-aluminium"},"source":"FAA Civil Aviation Registry, FAA airport file, NTSB accident database; assembled by eFlight Registry"}