Exhibit21

L-3Communications Holdings, Inc. and Subsidiaries As ofDecember 31, 2003

L-3 CommunicationsHoldings, Inc.  L-3 CommunicationsCorporation  Aviation Communications &Surveillance Systems, LLC (70%)  ACSS –NZSC Limited (70%)  Honeywell TCAS Inc.(70%)  Electrodynamics, Inc.  Henschel Inc.  Hygienetics EnvironmentalServices, Inc.  Interstate ElectronicsCorporation  KDI Precision Products, Inc.  L-3 Canada Acquisition Inc.  WescamInc.  1179023 Ontario Ltd  1374474Ontario Inc.  1415645 Ontario Inc.  3052893 Nova Scotia Company  AppliedPhysics Specialties Limited  3033544 Nova ScotiaCompany  Wescam Asia Pte Ltd (50%)  Wescam Europe Limited  Wescam Financial(U.S.A.) LLC  L-3 Communications Aeromet, Inc.  L-3 Communications AIS GP Corporation  L-3 Communications Integrated Systems L.P.(1%+99%)  L-3 Communications AeroTechLLC  Army Fleet Support, LLC (40%+40%)  J-R Technical Management, L.L.C.(50%)  J-R Technical Services LimitedPartnership, L.L.P. (49.5%+1%*50%)  L-3 Communications Flight Capital LLC  L-3 Communications Flight International Aviation LLC  L-3 Communications Vector International Aviation LLC  L3 Communications Australia Proprietary Limited  L-3 Communications Australia Pty Ltd  L-3Communications Avionics Systems, Inc.  L-3Communications Aydin Corporation  Aydin Foreign SalesLimited  L-3 Communications Global Network SolutionsU.K. Ltd.  L-3 Communications Investments Inc.  L-3 Communications Canada Inc.  L-3Communications MAS (Canada) Inc.  Spar AerospaceLimited  L-3 Communications ESSCO,Inc.  Electronic Space Systems International Corp.  ESSCO Collins Limited (99.99%)  L-3 Communications Government Services, Inc.  L-3 Communications Holding GmbH  L-3Communications ELAC Nautik GmbH  ELAC NautikUnterstützungskaße GmbH  Power Paragon(Deutschland) Holding GmbH (99% +1%)  EuroAtlas Gesellschaft für LeistungselektronikmbH

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L-3Communications Holdings, Inc. and Subsidiaries**— (continued)** As ofDecember 31, 2003

  JovyAtlas ElektrischeUmformtechnik GmbH (99% +1%)  NardaSafety Test Solutions GmbH  PMM CostuzioniElecttroniche Centro Misure Radioelettriche S.r.l. (98%)  L-3 Communications Hong Kong Limited  L-3Communications ILEX Systems, Inc.  L-3 CommunicationsKlein Associates, Inc.  L-3 Communications KoreaCorporation  L-3 Communications Malaysia Sdn.Bhd.  L-3 Communications MAS (US) Corporation  L-3 Communications Secure Information Technology,Inc.  L-3 Communications Security and DetectionSystems Corporation California  L-3 CommunicationsSecurity and Detection Systems Corporation Delaware  L-3 Communications Security Systems Corporation  L-3 Communications Singapore Pte Ltd  L-3Communications Storm Control Systems, Inc.  L-3Communications U.K. Ltd.  Storm Control SystemsLimited  L-3 Communications Westwood Corporation  Logimetrics, Inc. (55%)  Logimetrics FSC, Inc. (55%)  mmTECH, INC. (55%)  L-TresComunicaciones Cost Rica, S.A.  MicrodyneCorporation  Microdyne Communications TechnologiesIncorporated  MCTI Acquisition Corporation  Apcom, Inc.  L-3 Communications CSI,Inc.  Microdyne Ltd.  MicrodyneOutsourcing Incorporated  MPRI, Inc.  Ship Analytics, Inc.  Ship AnalyticsInternational, Inc.  Ship Analytics USA, Inc.  PacOrd Inc.  Power Paragon, Inc.  SPD Electrical Systems, Inc.  SPDSwitchgear Inc.  SYColeman Corporation  Wescam Holdings (US) Inc.  BroadcastSports Inc.  Troll Technology Corporation  Wescam Incorporated  Wescam Air OpsInc.  Wescam Air Ops LLC  WescamSonoma Inc.  Wescam LLC  Wolf Coach,Inc.

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