EXHIBIT 21 MARCH 1998 SUBSIDIARIES OF DYNCORP Name of Subsidiary Domicile (Active) Aerotherm Corporation California AT/Mexico Holdings, Inc. Delaware Data Management Design, Inc. Virginia Dyn Funding Corporation Delaware Dyn Marine Services, Inc. California Dyn Marine Services of Virginia, Inc. Virginia Dyn Network Management, Inc. Virginia Dyn Pacific Aerospace Services, Inc. Delaware Dyn Realty Corporation Virginia Dyn Systems Technology, Inc. Virginia Dyn Trade Systems, Inc. Virginia DynCIS, Inc. Delaware DynCorp Advanced Repair Technology, Inc. Virginia DynCorp Aerospace Operations, Inc. Delaware DynCorp Aerospace Operations (UK) Ltd. United Kingdom DynCorp Aviacion de Mexico S.A. de C.V. Mexico DynCorp Aviation Services, Inc. Virginia DynCorp Biotechnology and Health Services, Inc. Virginia DynCorp de Honduras S. De R.L. Honduras DynCorp Environmental, Energy & National Security Virginia Programs, Inc. DynCorp Information & Engineering Technology, Inc. Delaware DynCorp International Services GmbH Germany DynCorp International Services Inc. Virginia DynCorp International Services Ltd. Cayman Is. DynCorp of Colorado, Inc. Delaware DynCorp Panama, Inc. Panama DynCorp Postal Operations, Inc. Virginia DynCorp Procurement Systems, Inc. Virginia DynCorp Property Management, Inc. Delaware DynCorp Tri-Cities Services, Inc. Washington DynCorp Viar Inc. Virginia DynEDRS, Inc. Virginia DynEx, Inc. Virginia DynMet Corporation Delaware DynSolutions, Inc. Virginia DynTel Corporation Virginia FMAS Corporation Virginia TAI Realty Corporation Virginia Other Affiliated Companies Advanced Repair Technology, Int'l Ltd. Texas LLC DynBorg Security Management LLC Virginia DynCorp Management Resources LLC Virginia DynKePRO L.L.C. Delaware LLC DynMcDermott Petroleum Operations Company Louisiana DynPort LLC Virginia LLC DynPRI, LLC								 Virginia LLC DynStar LLC Virginia LLC TechServ LLC Virginia LLC Name of Subsidiary (Inactive) Anedyn, Inc. Georgia Anedyn Power Company Florida Dyn Logistics Services Inc. California DynAir Technical Services, Inc. Delaware Dynalectron Corporation Delaware Dynalectron Systems Inc. Nevada DynCorp Aviation Services, Inc. Virginia DynCorp of New Mexico, Inc. New Mexico DynCorp West Virginia Inc. West Virginia DynEagle Inc. Delaware Dyn/Mexico Holdings, Inc. Virginia Electric Utility Construction, Inc. Kentucky Fuller-Austin Insulation Company Delaware Grupo DynCorp de Mexico S.A. de C.V. Mexico Grupo DynCorp Satcom S.A. de C.V. Mexico Kwajalein Services, Inc. Virginia OLDHD Systems, Inc. Texas Pacific TSD Corporation California Sea Mobility Inc. Delaware