EXHIBIT 21 L-3 COMMUNICATIONS HOLDINGS, INC. AND SUBSIDIARIES AS OF DECEMBER 31, 2002 L-3 Communications Holdings, Inc. L-3 Communications Corporation AMI Instruments, Inc. Aviation Communications & Surveillance Systems, LLC (70%) ACSS - NZSC Limited (70%) Honeywell TCAS Inc. (70%) C3-ilex, LLC (25.2%) Delsub, Inc. Digital Technics, L.L.C. Digital Technics, L.P. (25% + 75%) EER Systems, Inc. Electrodynamics, Inc. Hygienetics Environmental Services, Inc. Interstate Electronics Corporation KDI Precision Products, Inc. L-3 Canada Acquisition Inc. Wescam Inc. 1374474 Ontario Inc. 1415645 Ontario Inc. 3052893 Nova Scotia Company Applied Physics Specialties Ltd. 1179023 Ontario Ltd 3033544 Nova Scotia Company Wescam Asia Pte Ltd (50%) Wescam Europe Limited Wescam Financial (U.S.A.) LLC (99.9% + .1%) Wescam Holdings (US) Inc. (94.3% + 5.7%) Broadcast Sports Inc. Troll Technology Corp. Wescam Incorporated Wescam Air Ops Inc. Wescam Air Ops LLC Wescam Sonoma Inc. Wescam LLC L-3 Communications AIS GP Corporation L-3 Communications Intergrated Systems L.P. (1%+99%) L-3 Communications Analytics Corporation Kapos Associates Inc. L-3 Communications Atlantic Science & Technology Corporation L3 Communications Australia Proprietary Limited L-3 Communications Australia Pty Ltd L-3 Communications Aydin Corporation Aydin Foreign Sales Limited L-3 Communications Global Network Solutions U.K. Ltd. L-3 Communications Investments Inc. L-3 Communications Canada Inc. Spar Aerospace Limited 3023001 Canada Inc. Godfrey Aerospace Inc. Spar Aviation Services (U.S.) Limited L-3 Communications ESSCO, Inc. L-3 COMMUNICATIONS HOLDINGS, INC. AND SUBSIDIARIES-- (CONTINUED) AS OF DECEMBER 31, 2002 Electronic Space Systems International Corp. Electronic Space Systems (UK) Limited (90%) ESSCO Collins Limited (99.99%) L-3 Communications Holding GmbH L-3 Communications ELAC Nautik GmbH ELAC Nautik Unterstutzungska\Se GmbH Power Paragon (Deutschland) Holding GmbH (99% +1%) EuroAtlas Gesellschaft fur Leistungselektronik mbH JovyAtlas Elektrische Umformtechnik GmbH Narda Safety Test Solutions GmbH PMM Costruzioni Electtroniche Centro Misure Radioelettriche S.r.l. (98%) L-3 Communications Hong Kong Limited L-3 Communications ILEX Systems, Inc. ITel Solutions, LLC (50%) Telos Corporation L-3 Communications IMC Corporation L-3 Communications Korea Corporation L-3 Communications Malaysia Sdn. Bhd. L-3 Communications Secure Information Technology, Inc. L-3 Communications Security and Detection Systems Corporation California L-3 Communications Security and Detection Systems Corporation Delaware L-3 Communications Security Systems Corporation L-3 Communications SPD Technologies, Inc. SPD Holdings, Inc. Henschel Inc. Pac Ord Inc. Power Paragon, Inc. SPD Electrical Systems, Inc. SPD Switchgear Inc. L-3 Communications Storm Control Systems, Inc. L-3 Communications TMA Corporation L-3 Communications U.K. Ltd. Storm Control Systems Limited L-3 Communications Westwood Corporation L-3 Satellite Networks, LLC LogiMetrics, Inc. (55%) Logimetrics FSC, Inc. (55%) mmTECH, INC. (55%) L-Tres Comunicaciones Costa Rica, S.A. Microdyne Corporation Microdyne Communications Technologies Incorporated MCTI Acquisition Corporation Apcom, Inc. Celerity Systems Incorporated Microdyne Ltd. Microdyne Outsourcing Incorporated L-3 COMMUNICATIONS HOLDINGS, INC. AND SUBSIDIARIES-- (CONTINUED) AS OF DECEMBER 31, 2002 MPRI, Inc. Ship Analytics, Inc. Ship Analytics International, Inc. Ship Analytics USA, Inc. Southern California Microwave, Inc. SYColeman Corporation TrexCom (Asia) PTE, Ltd. Wolf Coach, Inc.