Table of Contents

Exhibit12

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

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|                                                                               |  |  | YearEnded December31,                                  |
|                                                                               |  |  | 2006                                                   |   |         | 2005 |  |  | 2004 |   |         | 2003 |  |  | 2002 |
| Earnings:                                                                          |  |  | (inmillions, except ratio of earnings to fixedcharges) |
| Income before income taxes andcumulative effect of a change in accountingprinciple |  |  |                                                        | $ | 824.6   |      |  |  |      | $ | 788.3   |      |  |  |      | $ | 596.7  |   |  |  |  | $ | 433.8  |   |  |  |  | $ | 314.0  |   |
| Add:                                                                               |  |  |                                                        |   |    |      |  |  |      |   |    |      |  |  |      |   |   |   |  |  |  |   |   |   |  |  |  |   |   |   |
| Interestexpense                                                                    |  |  |                                                        |   | 285.9   |      |  |  |      |   | 199.0   |      |  |  |      |   | 138.1  |   |  |  |  |   | 124.7  |   |  |  |  |   | 115.1  |   |
| Amortizationof debtexpense                                                         |  |  |                                                        |   | 10.2    |      |  |  |      |   | 5.2     |      |  |  |      |   | 7.2    |   |  |  |  |   | 8.0    |   |  |  |  |   | 7.4    |   |
| Interestcomponent of rentexpense                                                   |  |  |                                                        |   | 53.6    |      |  |  |      |   | 40.4    |      |  |  |      |   | 26.8   |   |  |  |  |   | 24.4   |   |  |  |  |   | 22.4   |   |
| Earnings                                                                           |  |  |                                                        |   | 1,174.3 |      |  |  |      |   | 1,032.9 |      |  |  |      |   | 768.8  |   |  |  |  | $ | 590.9  |   |  |  |  | $ | 458.9  |   |
| Fixedcharges:                                                                      |  |  |                                                        |   |    |      |  |  |      |   |    |      |  |  |      |   |   |   |  |  |  |   |   |   |  |  |  |   |   |   |
| Interestexpense                                                                    |  |  |                                                        |   | 285.9   |      |  |  |      |   | 199.0   |      |  |  |      |   | 138.1  |   |  |  |  |   | 124.7  |   |  |  |  |   | 115.1  |   |
| Amortizationof debtexpense                                                         |  |  |                                                        |   | 10.2    |      |  |  |      |   | 5.2     |      |  |  |      |   | 7.2    |   |  |  |  |   | 8.0    |   |  |  |  |   | 7.4    |   |
| Interestcomponent of rentexpense                                                   |  |  |                                                        |   | 53.6    |      |  |  |      |   | 40.4    |      |  |  |      |   | 26.8   |   |  |  |  |   | 24.4   |   |  |  |  |   | 22.4   |   |
| Fixedcharges                                                                       |  |  |                                                        | $ | 349.7   |      |  |  |      | $ | 244.6   |      |  |  |      | $ | 172.1  |   |  |  |  | $ | 157.1  |   |  |  |  | $ | 144.9  |   |
| Ratioof earnings to fixedcharges                                                   |  |  |                                                        |   | 3.4     | x    |  |  |      |   | 4.2     | x    |  |  |      |   | 4.5    | x |  |  |  |   | 3.8    | x |  |  |  |   | 3.2    | x |
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