Exhibit21

L-3 Communications Holdings, Inc. AndSubsidiariesAs of December  31,2006

|                                                            |  |  |               |
|------------------------------------------------------------|--|--|---------------|
| Name                                                       |  |  | Jurisdiction  |
| L-3Communications Holdings,Inc.                            |  |  | Delaware      |
| L-3CommunicationsCorporation                               |  |  | Delaware      |
| AviationCommunications & Surveillance Systems,LLC*     |  |  | Delaware      |
| ACSS — NZSCLimited*                                  |  |  | New Zealand   |
| Honeywell TCASInc.*                                        |  |  | Delaware      |
| C3-ilex,LLC*                                               |  |  | California    |
| Combat AdvancedPropulsion,LLC*                             |  |  | Delaware      |
| Electrodynamics,Inc.                                       |  |  | Arizona       |
| HenschelInc.                                               |  |  | Delaware      |
| HygieneticsEnvironmental Services,Inc.                     |  |  | Delaware      |
| Interstate ElectronicsCorporation                          |  |  | California    |
| KDI PrecisionProducts, Inc.                                |  |  | Delaware      |
| L-3 CanadaAcquisition Inc.                                 |  |  | Canada        |
| WescamInc.                                                 |  |  | Canada        |
| Film EuropeLimited*                                        |  |  | Belgium       |
| Mosaic MappingInc.*                                        |  |  | Canada        |
| Wescam Asia PteLtd.*                                       |  |  | Singapore     |
| Wescam Financial(U.S.A.) LLC                               |  |  | Delaware      |
| L-3Communications Advanced Laser Systems Technology,Inc.   |  |  | Florida       |
| L-3 CommunicationsAeromet, Inc.                            |  |  | Oregon        |
| L-3Communications AIS GPCorporation                        |  |  | Delaware      |
| L-3Communications Integrated SystemsL.P.                   |  |  | Delaware      |
| Global MilitaryAircraft Systems, LLC*                      |  |  | Delaware      |
| L-3Communications Vertex AerospaceLLC                      |  |  | Delaware      |
| Army Fleet Support,LLC*                                    |  |  | Delaware      |
| J-R TechnicalManagement, L.L.C.*                           |  |  | Texas         |
| J-RTechnical Services Limited Partnership,L.L.P.*          |  |  | Texas         |
| L-3 CommunicationsFlight Capital LLC                       |  |  | Delaware      |
| L-3Communications Flight International AviationLLC         |  |  | Delaware      |
| L-3 CommunicationsVector International AviationLLC         |  |  | Delaware      |
| L-3 CommunicationsApplied Signal and Image Technology,Inc. |  |  | Maryland      |
| L-3 CommunicationsAustralia Group Pty Ltd                  |  |  | Australia     |
| L-3Communications Nautronix Limited                        |  |  | Australia     |
| McCorkills Marine PtyLtd                                   |  |  | Australia     |
| Nautronix Asia PacificPte Limited                          |  |  | Singapore     |
|     TerraCable Singapore PteLtd        |  |  | Singapore     |
| Nautronix (Singapore)Pte Ltd                               |  |  | Singapore     |
| L-3 CommunicationsAustralia ProprietaryLimited             |  |  | Australia     |
| L-3 CommunicationsAustralia Pty Ltd                        |  |  | Australia     |
| L-3Communications Avionics Systems,Inc.                    |  |  | Delaware      |
| L-3 CommunicationsAVISYS Corporation                       |  |  | Texas         |
| L-3Communications AydinCorporation                         |  |  | Delaware      |
| Aydin ForeignSales Limited                                 |  |  | Guam          |
| AydinS.A.*                                                 |  |  | Argentina     |
| L-3 CommunicationsGlobal Network Solutions U.K. Ltd.       |  |  | UnitedKingdom |
| L-3 Communications InvestmentsInc.                         |  |  | Delaware      |
|                                                            |

----

L-3 Communications Holdings, Inc. AndSubsidiaries (Continued)As of December  31,2006

|                                                                   |  |  |                     |
|-------------------------------------------------------------------|--|--|---------------------|
| Name                                                              |  |  | Jurisdiction        |
| Aydin Yazilim ve ElektronikSanayi A.S.*                           |  |  | Turkey              |
| L-3Communications Canada Inc.                                     |  |  | Canada              |
| L-3Communications Electronic SystemsInc.                          |  |  | Canada              |
| L-3 Communications MAS(Canada) Inc.                               |  |  | Canada              |
| Spar AerospaceLimited                                             |  |  | Canada              |
| InternationalAerospace Management Company Scrl*                   |  |  | Republic ofItaly    |
| Sovcan Star Satellite CommunicationsInc.*                         |  |  | Canada              |
| L-3 Communications CEHoldings, Inc.                               |  |  | Delaware            |
| L-3Communications Cincinnati ElectronicsCorporation               |  |  | Ohio                |
| L-3 CommunicationsCrestview AerospaceCorporation                  |  |  | Delaware            |
| L-3Communications CyTerraCorporation                              |  |  | Delaware            |
| L-3Communications Electron Technologies,Inc.                      |  |  | Delaware            |
| L-3 CommunicationsEOTech, Inc.                                    |  |  | Delaware            |
| L-3Communications ESSCO,Inc.                                      |  |  | Delaware            |
| Electronic SpaceSystems International Corp.                       |  |  | U.S. VirginIslands  |
| ESSCO CollinsLimited                                              |  |  | Republic of Ireland |
| L-3Communications Foreign Holdings,Inc.                           |  |  | Delaware            |
| L-3 CommunicationsGermany Holdings, LLC                           |  |  | Delaware            |
| L-3Communications Vermögensverwaltungs GmbH & Co.KG      |  |  | Germany             |
| L-3 CommunicationsGovernment Services,Inc.                        |  |  | Virginia            |
| D.P. AssociatesInc.                                               |  |  | Virginia            |
| L-3 CommunicationsHolding GmbH                                    |  |  | Germany             |
| L-3Communications ELAC NautikGmbH                                 |  |  | Germany             |
| ELAC NautikUnterstützungskaßeGmbH                      |  |  | Germany             |
| L-3 CommunicationsMagnet-Motor GmbH                               |  |  | Germany             |
| PowerParagon (Deutschland) HoldingGmbH                            |  |  | Germany             |
| EuroAtlas Gesellschaftfür LeistungselektronikmbH             |  |  | Germany             |
| JovyAtlas ElektrischeUmformtechnik GmbH                           |  |  | Germany             |
| AstridEnergy Enterprises S.r.l.*                                  |  |  | Republic ofItaly    |
| Narda Safety Test SolutionsGmbH                                   |  |  | Germany             |
| PMM CostruzioniElecttroniche Centro Misure Radioelettriche S.r.l. |  |  | Republic ofItaly    |
|     EMC S.r.l.*                               |  |  | Republic ofItaly    |
| SAM ElectronicsGmbH                                               |  |  | Germany             |
| DebegGmbH                                                         |  |  | Germany             |
| DebegVersorgungseinrichtungGmbH                                   |  |  | Germany             |
| Lyngsø MarineA/S                                           |  |  | Denmark             |
| AmplidanA/S                                                       |  |  | Denmark             |
| NordakademiegAG*                                                  |  |  | Germany             |
| SAM East AsiaLtd.                                                 |  |  | Hong Kong           |
| SAM Electronics JapanLtd.                                         |  |  | Japan               |
| SAM Electronics Korea Co.Ltd.                                     |  |  | Korea               |
| SAM Electronics NederlandB.V.                                     |  |  | Netherlands         |
| SAM ElectronicsNorge A/S                                          |  |  | Norway              |
| SAM Electronics UKLtd.                                            |  |  | United Kingdom      |
| SAM TaihangElectronics Co. Ltd.*                                  |  |  | China               |
| STNSchiffselektrik VerwaltungsGmbH                                |  |  | Germany             |
| STN Schiffselektrik GmbH& Co. KG                              |  |  | Germany             |
|     MGSMontage GmbH                           |  |  | Germany             |
|                                                                   |

----

L-3 Communications Holdings, Inc. AndSubsidiaries (Continued)As of December  31,2006

|                                                                                                       |  |  |                    |
|-------------------------------------------------------------------------------------------------------|--|--|--------------------|
| Name                                                                                                  |  |  | Jurisdiction       |
| W.G. SchulzGmbH                                                                                       |  |  | Germany            |
| L-3 Communications HongKong Limited                                                                   |  |  | Hong Kong          |
| L-3Communications ILEX Systems,Inc.                                                                   |  |  | Delaware           |
| L-3 CommunicationsIndia Private Limited                                                               |  |  | India              |
| L-3Communications InfraredVision TechnologyCorporation                                                |  |  | California         |
| L-3Communications Italy S.r.l.                                                                        |  |  | Republic ofItaly   |
| L-3 Communications Klein Associates,Inc.                                                              |  |  | Delaware           |
| L-3 CommunicationsKorea Corporation                                                                   |  |  | South Korea        |
| L-3Communications Ltd.                                                                                |  |  | UnitedKingdom      |
| L-3 Communications Group Limited                                                                      |  |  | United Kingdom     |
| L-3 Communications U.K.Ltd.                                                                           |  |  | United Kingdom     |
|     ASATechnologies Limited                                                       |  |  | UnitedKingdom      |
|         Advanced SystemsArchitectures (Holdings) Limited      |  |  | UnitedKingdom      |
|             L-3 CommunicationsASA Limited |  |  | United Kingdom     |
|     TRLElectronics Limited                                                        |  |  | UnitedKingdom      |
|         TRL TechnologyLimited                                 |  |  | United Kingdom     |
| L-3Communications Malaysia Sdn.Bhd.                                                                   |  |  | Malaysia           |
| L-3 CommunicationsMAPPS Malaysia Sdn. Bhd.                                                            |  |  | Malaysia           |
| L-3Communications MAPPS Inc.                                                                          |  |  | Canada             |
| L-3Communications MAPPS Investments,LLC                                                               |  |  | Delaware           |
| L-3 CommunicationsMarine Holdings AS                                                                  |  |  | Norway             |
| L-3Communications ValmarineAS                                                                         |  |  | Norway             |
| L-3 CommunicationsNavigation AS                                                                       |  |  | Norway             |
| L-3Communications Marine Systems UK Ltd.                                                              |  |  | UnitedKingdom      |
| FAST Holdings Limited*                                                                                |  |  | UnitedKingdom      |
| FAST Training ServicesLimited*                                                                        |  |  | United Kingdom     |
| L-3Communications MAS (US)Corporation                                                                 |  |  | Delaware           |
| L-3Communications Mobile-Vision, Inc.                                                                 |  |  | NewJersey          |
| L-3 Communications Nautronix Holdings,Inc.                                                            |  |  | Delaware           |
| L-3 CommunicationsDynamic Positioning and Control Systems,Inc.                                        |  |  | California         |
| L-3 CommunicationsMariPro, Inc.                                                                       |  |  | California         |
| L-3Communications Nova Engineering,Inc.                                                               |  |  | Ohio               |
| L-3 CommunicationsSafeView, Inc.                                                                      |  |  | Delaware           |
| L-3Communications Security and Detection Systems,Inc.                                                 |  |  | Delaware           |
| L-3 CommunicationsSingapore Pte Ltd                                                                   |  |  | Singapore          |
| L-3Communications Sonoma EO,Inc.                                                                      |  |  | California         |
| L-3 CommunicationsSSG-Tinsley, Inc.                                                                   |  |  | Delaware           |
| L-3Communications Tinsley Laboratories,Inc.                                                           |  |  | California         |
| L-3 CommunicationsTCS, Inc.                                                                           |  |  | Georgia            |
| L-3 CommunicationsTitan Corporation                                                                   |  |  | Delaware           |
| Cayenta,Inc.*                                                                                         |  |  | Delaware           |
| Datron / Trans WorldCommunications Int’l. Ltd.                                                  |  |  | U.S. VirginIslands |
| EngilityCorp.                                                                                         |  |  | Delaware           |
| Horizons TechnologyInternational, Ltd.                                                                |  |  | Barbados           |
| LinComWireless, Inc.*                                                                                 |  |  | Delaware           |
| Sakon,LLC*                                                                                            |  |  | Delaware           |
| Sakon Calling Cards,LLC*                                                                              |  |  | New Jersey         |
| Titan DeutschlandGmbH                                                                                 |  |  | Germany            |
|                                                                                                       |

----

L-3 Communications Holdings, Inc. AndSubsidiaries (Continued)As of December  31,2006

|                                                  |  |  |                    |
|--------------------------------------------------|--|--|--------------------|
| Name                                             |  |  | Jurisdiction       |
| Titan Facilities,Inc.                            |  |  | Virginia           |
| Delta Lord JointVenture*                         |  |  | Florida            |
| Titan ItaliaS.r.l.                               |  |  | Republic of Italy  |
| TitanSystems Solutions UK Ltd.                   |  |  | UnitedKingdom      |
| Titan Wireless,Inc.*                             |  |  | Delaware           |
| Storm Control SystemsLimited                     |  |  | United Kingdom     |
| L-3Communications VerwaltungsGmbH                |  |  | Germany            |
| L-3 CommunicationsWestwood Corporation           |  |  | Nevada             |
| L-TresComunicaciones Cost Rica, S.A.             |  |  | CostaRica          |
| Medical Education Technologies,Inc.*             |  |  | Delaware           |
| MicrodyneCorporation                             |  |  | Maryland           |
| MicrodyneCommunications TechnologiesIncorporated |  |  | Maryland           |
| MCTIAcquisitionCorporation                       |  |  | Maryland           |
| Apcom,Inc.                                       |  |  | Maryland           |
| L-3 Communications CSI,Inc.                      |  |  | California         |
| MicrodyneLtd.                                    |  |  | U.S Virgin Islands |
| MicrodyneOutsourcingIncorporated                 |  |  | Maryland           |
| MPRI,Inc.                                        |  |  | Delaware           |
| Civilian PoliceInternational, LLC*               |  |  | Delaware           |
| CPIPolice Services, Ltd.*                        |  |  | CaymanIslands      |
| Forfeiture Support Associates,L.L.C.*            |  |  | Delaware           |
| gForce Technologies,Inc.                         |  |  | Massachusetts      |
| MPRI InternationalServices, Ltd.                 |  |  | Bermuda            |
| MVT EquityLLC*                                   |  |  | Delaware           |
| New SI,LLC                                       |  |  | Delaware           |
| Pac OrdInc.                                      |  |  | Delaware           |
| Power Paragon,Inc.                               |  |  | Delaware           |
| SPD Electrical Systems,Inc.                      |  |  | Delaware           |
| SPD SwitchgearInc.                               |  |  | Delaware           |
| SYColemanCorporation                             |  |  | Florida            |
| URS Coleman,LLC*                                 |  |  | Maryland           |
| Wescam Holdings (US)Inc.                         |  |  | Delaware           |
| Broadcast SportsInc.                             |  |  | Delaware           |
| L-3 CommunicationsEO/IR, Inc.                    |  |  | Florida            |
| Wescam Air OpsInc.                               |  |  | Delaware           |
| Wescam Air OpsLLC                                |  |  | Delaware           |
| Troll TechnologyCorporation                      |  |  | California         |
| WescamLLC                                        |  |  | Delaware           |
| Wolf Coach,Inc.                                  |  |  | Massachusetts      |
|                                                  |

|  |
|--|
|  |  |
|  |

|   |                                         |
|---|-----------------------------------------|
| * | Representsnon-wholly ownedsubsidiaries. |

----