(Cost in Millions of Dollars Excluding Regional Jet Contract Expenses per Aircraft)
| 2006 Rank | Network | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | Change 2001-2006 |
|---|---|---|---|---|---|---|---|---|
| 1 | United | 6.712 | 6.375 | 6.370 | 7.127 | 8.136 | 7.998 | 1.286 |
| 2 | Continental | 5.325 | 5.604 | 5.508 | 6.297 | 6.641 | 6.947 | 1.622 |
| 3 | Delta | 5.129 | 5.750 | 5.848 | 6.157 | 6.997 | 6.873 | 1.744 |
| 4 | American | 5.404 | 6.028 | 5.743 | 5.996 | 6.672 | 6.855 | 1.451 |
| 5 | Northwest | 5.076 | 5.589 | 5.520 | 6.177 | 6.487 | 6.283 | 1.207 |
| 6 | Alaska | 4.462 | 4.719 | 4.904 | 5.351 | 6.718 | 5.797 | 1.335 |
| 7 | US Airways | 5.317 | 5.070 | 5.292 | 4.628 | 5.438 | 5.638 | 0.321 |
| 7-Carrier Average | 5.480 | 5.800 | 5.742 | 6.105 | 6.846 | 6.836 | 1.356 |
Source: Bureau of Transportation Statistics, Form 41 Airline Financial Data