Exhibit 21

L-3 Communications Holdings, Inc. and Subsidiaries
As of December 31, 2004

L-3 Communications Holdings, Inc.
L-3 Communications Corporation
6292151 Canada Inc.
L-3 Communications Electronic Systems
135363 Canada Inc.
Aviation Communications & Surveillance Systems, LLC (70%)
ACSS – NZSC Limited (70%)
Honeywell TCAS Inc. (70%)
C3-ilex, LLC (25.2%)
CMC Holdings, Inc.
L-3 Communications Cincinnati Electronics Corporation
Sonoma Design Group, Inc. (34%)
Electrodynamics, Inc.
Henschel Inc.
Hygienetics Environmental Services, Inc.
Interstate Electronics Corporation
KDI Precision Products, Inc.
L-3 Canada Acquisition Inc.
Wescam Inc.
1179023 Ontario Ltd
1374474 Ontario Inc.
Film Europe Limited (20%)
Mosaic Mapping Inc. (14%)
New Vision Group Inc. (10%)
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 Vertex Aerospace LLC
Army Fleet Support, LLC (40% +40%)
J-R Technical Management, L.L.C. (50%)
J-R Technical Services Limited Partnership, 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-3 Communications Avionics Systems, Inc.
L-3 Communications AVISYS Corporation
L-3 Communications Aydin Corporation
Aydin Foreign Sales Limited
Aydin S.A. (19%)
L-3 Communications Global Network Solutions U.K. Ltd.
L-3 Communications Investments Inc.
Aydin Yazilim ve Elektronik Sanayi A.S. (100%)
L-3 Communications Canada Inc.
L-3 Communications MAS (Canada) Inc.
Spar Aerospace Limited

L-3 Communications Holdings, Inc. and Subsidiaries — (continued)
As of December 31, 2004

International Aerospace Management Company Scrl (20%)
Sovcan Star Satellite Communications Inc. (34%)
L-3 Communications ESSCO, Inc.
Electronic Space Systems International Corp.
ESSCO Collins Limited (99.99%)
L-3 Communications Government Services, Inc.
D.P. Associates, Inc.
L-3 Communications Holding GmbH
ELAC Nautik Unterstützungskaße GmbH
Power Paragon (Deutschland) Holding GmbH (99% +1%)
EuroAtlas Gesellschaft für Leistungselektronik mbH
JovyAtlas Elektrische Umformtechnik GmbH (99% +1%)
Astrid Energy Enterprises S.R.L (10%)
Narda Safety Test Solutions GmbH
PMM Costuzioni Electtroniche Centro Misure Radioelettriche S.r.l. (98%)
EMC S.r.l. (33%)
L-3 Communications Hong Kong Limited
L-3 Communications ILEX Systems, Inc.
L-3 Communications Klein Associates, Inc.
L-3 Communications Korea Corporation
L-3 Communications Malaysia Sdn. Bhd.
L-3 Communications MAS (US) Corporation
L-3 Communications Security and Detection Systems, Inc.
L-3 Communications Singapore Pte Ltd.
L-3 Communications Storm Control Systems, Inc.
L-3 Communications U.K. Ltd.
Strom Control Systems Limited
L-3 Communications Westwood Corporation
L-Tres Comunicaciones Cost Rica, S.A.
Medical Education Technologies, Inc. (47.5%)
Microdyne Corporation
Microdyne Communications Technologies Incorporated
MCTI Acquisition Corporation
Apcom, Inc.
L-3 Communications CSI, Inc.
Microdyne Ltd.
Microdyne Outsourcing Incorporated
MPRI, Inc.
Civilian Police International, LLC (30%)
Civilian Police International, Ltd. (30%)
Ship Analytics, Inc.
Ship Analytics International, Inc.
Ship Analytics USA, Inc.
MVT Equity LLC (33.3%)
New SI, LLC
PacOrd Inc.
Power Paragon, Inc.
SPD Electrical Systems, Inc.
SPD Switchgear Inc.
SYColeman Corporation
Wescam Holdings (US) Inc.

L-3 Communications Holdings, Inc. and Subsidiaries — (continued)
As of December 31, 2004

Broadcast Sports Inc.
Troll Technology Corporation
Wescam Incorporated
Wescam Air Ops Inc.
Wescam Air Ops LLC
Wescam Sonoma Inc.
Wescam LLC
Wolf Coach, Inc.