Exhibit12

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

|                                                                                    |  |                       |         |        |  |        |         |        |  |        |         |        |  |        |         |        |  |        |         |        |  |  |
|------------------------------------------------------------------------------------|--|-----------------------|---------|--------|--|--------|---------|--------|--|--------|---------|--------|--|--------|---------|--------|--|--------|---------|--------|--|--|
|                                                                               |  | YearEnded December31, |
|                                                                               |  | 2004                  |         | 2003   |  | 2002   |         | 2001   |  | 2000   |
| Earnings:                                                                          |  |                  |    |   |  |   |    |   |  |   |    |   |  |   |    |   |  |   |    |   |
| Incomebefore income taxes and cumulative effect of a change in accountingprinciple |  | $                     | 596,688 |   |  | $      | 433,813 |   |  | $      | 314,023 |   |  | $      | 186,222 |   |  | $      | 134,079 |   |
| Add:                                                                               |  |                  |    |   |  |   |    |   |  |   |    |   |  |   |    |   |  |   |    |   |
| Interestexpense                                                                    |  |                  | 138,153 |   |  |   | 124,706 |   |  |   | 115,100 |   |  |   | 80,002  |   |  |   | 87,308  |   |
| Amortizationof debtexpense                                                         |  |                  | 7,195   |   |  |   | 7,977   |   |  |   | 7,392   |   |  |   | 6,388   |   |  |   | 5,724   |   |
| Interestcomponent of rentexpense                                                   |  |                  | 26,814  |   |  |   | 24,364  |   |  |   | 22,342  |   |  |   | 14,332  |   |  |   | 11,882  |   |
| Earnings                                                                           |  |                  | 768,850 |   |  | $      | 590,860 |   |  | $      | 458,857 |   |  | $      | 286,944 |   |  | $      | 238,993 |   |
| Fixedcharges:                                                                      |  |                  |    |   |  |   |    |   |  |   |    |   |  |   |    |   |  |   |    |   |
| Interestexpense                                                                    |  |                  | 138,153 |   |  |   | 124,706 |   |  |   | 115,100 |   |  |   | 80,002  |   |  |   | 87,308  |   |
| Amortizationof debtexpense                                                         |  |                  | 7,195   |   |  |   | 7,977   |   |  |   | 7,392   |   |  |   | 6,388   |   |  |   | 5,724   |   |
| Interestcomponent of rentexpense                                                   |  |                  | 26,814  |   |  |   | 24,364  |   |  |   | 22,342  |   |  |   | 14,332  |   |  |   | 11,882  |   |
| Fixedcharges                                                                       |  |                  | 172,162 |   |  | $      | 157,047 |   |  | $      | 144,834 |   |  | $      | 100,722 |   |  | $      | 104,914 |   |
| Ratioof earnings to fixedcharges                                                   |  |                  | 4.5x    |   |  |   | 3.8x    |   |  |   | 3.2x    |   |  |   | 2.8x    |   |  |   | 2.3x    |   |
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