L-3Communications Holdings, Inc.and L-3 CommunicationsCorporationRatio of Earnings to Fixed Charges

Exhibit12

|                                                                                    |  |                       |         |         |  |        |         |         |  |        |         |         |  |        |         |         |  |        |         |         |  |  |
|------------------------------------------------------------------------------------|--|-----------------------|---------|---------|--|--------|---------|---------|--|--------|---------|---------|--|--------|---------|---------|--|--------|---------|---------|--|--|
|                                                                               |  | L-3                   |
|                                                                               |  | YearEnded December31, |
|                                                                               |  | 2003                  |         | 2002    |  | 2001   |         | 2000    |  | 1999   |
| Earnings:                                                                          |  |
| Incomebefore income taxes and cumulative effect of a change in accountingprinciple |  | $                     | 433,813 |    |  | $      | 314,023 |    |  | $      | 186,222 |    |  | $      | 134,079 |    |  | $      | 95,430  |    |
| Add:                                                                               |  |
| Interestexpense                                                                    |  |                  | 124,706 |    |  |   | 115,100 |    |  |   | 80,002  |    |  |   | 87,308  |    |  |   | 56,686  |    |
| Amortizationof debtexpense                                                         |  |                  | 7,977   |    |  |   | 7,392   |    |  |   | 6,388   |    |  |   | 5,724   |    |  |   | 3,904   |    |
| Interestcomponent of rentexpense                                                   |  |                  | 24,364  |    |  |   | 22,342  |    |  |   | 14,332  |    |  |   | 11,882  |    |  |   | 7,500   |    |
| Earnings                                                                           |  | $                     | 590,860 |    |  | $      | 458,857 |    |  | $      | 286,944 |    |  | $      | 238,993 |    |  | $      | 163,520 |    |
| Fixedcharges:                                                                      |  |
| Interestexpense                                                                    |  |                  | 124,706 |    |  |   | 115,100 |    |  |   | 80,002  |    |  |   | 87,308  |    |  |   | 56,686  |    |
| Amortizationof debtexpense                                                         |  |                  | 7,977   |    |  |   | 7,392   |    |  |   | 6,388   |    |  |   | 5,724   |    |  |   | 3,904   |    |
| Interestcomponent of rentexpense                                                   |  |                  | 24,364  |    |  |   | 22,342  |    |  |   | 14,332  |    |  |   | 11,882  |    |  |   | 7,500   |    |
| Fixedcharges                                                                       |  | $                     | 157,047 |    |  | $      | 144,834 |    |  | $      | 100,722 |    |  | $      | 104,914 |    |  | $      | 68,090  |    |
| Ratioof earnings to fixedcharges                                                   |  |                  | 3.8     | x  |  |   | 3.2     | x  |  |   | 2.8     | x  |  |   | 2.3     | x  |  |   | 2.4     | x  |
|                                                                                    |

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