Exhibit 22.1

LISTING OF SUBSIDIARY GUARANTORS

The following series of senior subordinated and secured notes issued by TransDigm Inc., a wholly owned subsidiary of TransDigm Group Incorporated, are unconditionally guaranteed, on a joint and several basis, by TransDigm Group Incorporated and each of the subsidiaries listed below under “Subsidiary Guarantors.”

			Description
			6.750% senior secured notes due 2028 (“2028 Secured Notes”)
			4.625% senior subordinated notes due 2029 (“4.625% 2029 Notes”)
			6.375% senior secured notes due 2029 (“2029 Secured Notes”)
			4.875% senior subordinated notes due 2029 (“4.875% 2029 Notes”)
			6.875% senior secured notes due 2030 (“2030 Secured Notes”)
			7.125% senior secured notes due 2031 (“2031 Secured Notes”)
			6.625% senior secured notes due 2032 (“2032 Secured Notes”)
			6.000% senior secured notes due 2033 (“2033 Secured Notes”)
			6.375% senior subordinated notes due 2033 (“6.375% 2033 Notes”)
			6.250% senior secured notes due 2034 (“2034 Secured Notes”)
			6.750% senior subordinated notes due 2034 (“6.750% 2034 Notes”)
			6.125% senior subordinated notes due 2034 (“6.125% 2034 Notes”)

			Subsidiary Guarantors						Jurisdiction of Incorporation or Organization
			4455 Genesee Properties, LLC						Delaware
			4455 Genesee Street, LLC						Delaware
			17111 Waterview Pkwy LLC						Delaware
			Acme Aerospace, Inc.						Delaware
			Adams Rite Aerospace, Inc.						California
			AeroControlex Group, Inc.						Delaware
			Aero Accessories, LLC						North Carolina
			Aero Aviation Company LLC						Illinois
			Aero Group Holdings LLC						North Carolina
			Aero Parts Mart, Inc.						Texas
			Aerosonic LLC						Delaware
			Aerotech of Louisville LLC						Delaware
			Airborne Acquisition, Inc.						Delaware
			Airborne Global, Inc.						Delaware
			Airborne Holdings, Inc.						Delaware
			Airborne Systems NA Inc.						Delaware
			Airborne Systems North America Inc.						Delaware
			Airborne Systems North America of CA Inc.						Delaware
			Airborne Systems North America of NJ Inc.						New Jersey
			Airforms LLC						Delaware
			Airframes Alaska LLC						Delaware
			Airline Component Parts, LLC						Texas
			Alcor, LLC						North Carolina
			American Fuel Cell and Coated Fabrics Company, LLC						Delaware
			AmSafe Global Holdings, Inc.						Delaware
			AmSafe, Inc.						Delaware
			Angus Electronics Co.						Delaware

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			Subsidiary Guarantors						Jurisdiction of Incorporation or Organization
			Apical Industries, Inc.						California
			APS Mfg LLC						Delaware
			Arkwin Industries, Inc.						New York
			Armtec Countermeasures Co.						Delaware
			Armtec Countermeasures TNO Co.						Delaware
			Armtec Defense Products Co.						Delaware
			Ashford Properties, LLC						Delaware
			Auxitrol Weston USA, Inc.						Delaware
			AV8 MRO LLC						Texas
			AV8 PMA LLC						Texas
			Aviation Products Systems LLC						Delaware
			Aviation Technologies, Inc.						Delaware
			Avionic Instruments LLC						Delaware
			Avionics Specialties, Inc.						Virginia
			AvtechTyee, Inc.						Washington
			Beta Transformer Technology LLC						Delaware
			Breeze-Eastern LLC						Delaware
			Bridport Erie Aviation, Inc.						Delaware
			Bridport Holdings, Inc.						Delaware
			Bridport-Air Carrier, Inc.						Washington
			Bruce Aerospace Inc.						Delaware
			Calspan Air Facilities, LLC						New York
			Calspan Air Services, LLC						New York
			Calspan ASE Portugal, Inc.						Minnesota
			Calspan Holdings, LLC						New York
			CALSPAN JETS LLC						Delaware
			Calspan Technology Acquisition LLC						Delaware
			Calspan, LLC						New York
			CDA InterCorp LLC						Florida
			CEF Industries, LLC						Delaware
			Champion Aerospace LLC						Delaware
			Chelton Avionics Holdings, Inc.						Delaware
			Chelton Avionics, Inc.						Delaware
			Chelton Defense Products, Inc.						Delaware
			CIMA Aviation LLC						Delaware
			CJ Aviation Products, LLC						Kansas
			CMC Electronics Aurora LLC						Delaware
			Consolidated Fuel Systems LLC						North Carolina
			CPI EDB Intermediate Holdings, Inc.						Delaware
			CPI Electron Device Business, Inc.						Delaware
			CTHC LLC						New York
			Dart Aerospace USA, Inc.						Washington
			Dart Buyer, Inc.						Delaware
			Dart Helicopter Services, Inc.						Delaware

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			Subsidiary Guarantors						Jurisdiction of Incorporation or Organization
			Dart Intermediate, Inc.						Delaware
			Dart TopCo, Inc.						Delaware
			Data Device Corporation						Delaware
			Dukes Aerospace, Inc.						Delaware
			Eastern OptX, Inc.						New Jersey
			Electromech Technologies LLC						Delaware
			Esterline Europe Company LLC						Delaware
			Esterline International Company						Delaware
			Esterline Technologies Corporation						Delaware
			Esterline Technologies SGIP LLC						Delaware
			FPT Industries LLC						Delaware
			Genesee Holdings II, LLC						New York
			Genesee Holdings III, LLC						New York
			Genesee Holdings, LLC						New York
			Gibson Accumulator LLC						North Carolina
			Great River Technology Incorporated						New Mexico
			HarcoSemco LLC						Connecticut
			Hartwell Corporation						California
			Horizon, LLC						Kansas
			Hytek Finishes Co.						Delaware
			Iceman Holdco, Inc.						Delaware
			ILC Holdings, Inc.						Delaware
			In-Phase Technologies, Incorporated						New Jersey
			Janco Corporation						California
			Jet Parts Engineering LLC						Delaware
			Johnson Liverpool LLC						Delaware
			JPE Holdings LLC						Delaware
			King Nutronics, LLC						Delaware
			Kirkhill Inc.						Delaware
			Korry Electronics Co.						Delaware
			Leach Holding Corporation						Delaware
			Leach International Corporation						Delaware
			Leach Mexico Holding LLC						Delaware
			Leach Technology Group, Inc.						Delaware
			Liquid Measurement Systems						Vermont
			MarathonNorco Aerospace, Inc.						Delaware
			Marvel-Schebler Aircraft Carburetors LLC						North Carolina
			Mason Electric Co.						Delaware
			McFarlane Aviation, LLC						Kansas
			McKechnie Aerospace DE, Inc.						Delaware
			McKechnie Aerospace Holdings, Inc.						Delaware
			McKechnie Aerospace US LLC						Delaware
			Medtherm Labs, LLC						Delaware
			Microwave Power Products, Inc.						Delaware

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			Subsidiary Guarantors						Jurisdiction of Incorporation or Organization
			Mitchell PMA LLC						Illinois
			NAT Seattle Inc.						Delaware
			NMC Group, Inc.						California
			Nordisk Aviation Products LLC						Delaware
			Northeast Aero Compressor Corp						New York
			North Hills Signal Processing Corp.						Delaware
			North Hills Signal Processing Overseas LLC						Delaware
			Norwich Aero Products Inc.						New York
			Offshore Helicopter Support Services, Inc.						Louisiana
			Oppenheimer Precision Products, Inc.						Pennsylvania
			Palomar Products, Inc.						Delaware
			Percival Aviation Inc.						Delaware
			Pexco Aerospace, Inc.						Delaware
			PG Aerotech LLC						Delaware
			PMA Products LLC						Delaware
			PneuDraulics, Inc.						California
			Power Device Corporation						New York
			Precision Airmotive, LLC						North Carolina
			Raptor Labs HoldCo, LLC						Delaware
			Raptor Labs Intermediate, LLC						Delaware
			Schneller LLC						Delaware
			Semco Instruments, Inc.						Delaware
			Sensor Concepts, LLC						Delaware
			Servotronics, Inc.						Delaware
			Shield Restraint Systems, Inc.						Delaware
			Simmonds Precision Products, Inc.						New York
			Simplex Manufacturing Co.						Oregon
			Skandia, Inc.						Illinois
			Skurka Aerospace Inc.						Delaware
			Space Electronics LLC						Delaware
			Stratus Tool Technologies, LLC						North Carolina
			Symetrics Industries, LLC						Florida
			TA Aerospace Co.						California
			Tactair Fluid Controls, Inc.						New York
			TDG ESL Holdings Inc.						Delaware
			TEAC Aerospace Technologies, Inc.						Delaware
			Telair US LLC						Delaware
			Tempest Aero Group, LLC						North Carolina
			TestVonics, Inc.						New Hampshire
			Texas Rotronics, Inc.						Texas
			TransDigm UK Holdings Limited						United Kingdom
			Transicoil LLC						Delaware
			Turn and Bank Holdings, LLC						North Carolina
			Victor Sierra Aviation Holdings LLC						Delaware

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			Subsidiary Guarantors						Jurisdiction of Incorporation or Organization
			VSC Aviation Acquisition LLC						Delaware
			VSC Aviation Holdings Intermediate LLC						Delaware
			VSC III MA, Inc.						Delaware
			VSC JPE, Inc.						Delaware
			Whippany Actuation Systems, LLC						Delaware
			Young & Franklin Inc.						New York