**Exhibit 31.1**

Certification of the Principal Executive OfficerPursuant to 15 U.S.C. 78m(a) or 78o(d)(Section 302 of the Sarbanes-Oxley Act of 2002)

I, Glenn F. Tilton,the Chairman, President and Chief Executive Officer of United Air Lines, Inc.(the “Company”), certify that:

(1)                       I havereviewed this quarterly report on Form 10-Q for the period ended September 30,2006 of the Company;

(2)                       Based on myknowledge, this report does not contain any untrue statement of a material factor omit to state a material fact necessary to make the statements made, inlight of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

(3)                       Based on myknowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the Company as of, and for,the periods presented in this report;

(4)                       The Company’sother certifying officer and I are responsible for establishing and maintainingdisclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) and internal control over financial reporting (as defined inExchange Act Rules 13a-15(f) and 15d-15(f)) for the Companyand have:

(a)           Designedsuch disclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the Company, including its consolidated subsidiaries,is made known to us by others within those entities, particularly during theperiod in which this report is being prepared;

(b)          Designedsuch internal control over financial reporting, or caused such internal controlover financial reporting to be designed under our supervision, to providereasonable assurance regarding the reliability of financial reporting and thepreparation of financial statements for external purposes in accordance withgenerally accepted accounting principles;

(c)           Evaluatedthe effectiveness of the Company’s disclosure controls and procedures andpresented in this report our conclusions about the effectiveness of thedisclosure controls and procedures, as of the end of the period covered by thisreport based on such evaluation; and

(d)          Disclosedin this report any change in the Company’s internal control over financialreporting that occurred during the Company’s most recent fiscal quarter thathas materially affected, or is reasonably likely to materially affect, theCompany’s internal control over financial reporting; and

(5)                       The Company’sother certifying officer and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to the Company’sauditors and the audit committee of Company’s board of directors (or personsperforming the equivalent functions):

(a)           Allsignificant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely toadversely affect the Company’s ability to record, process, summarize and reportfinancial information; and

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(b)          Anyfraud, whether or not material, that involves management or other employees whohave a significant role in the Company’s internal control over financialreporting.
| /s/ Glenn F. Tilton                              |   |
|--------------------------------------------------|--------|
| Glenn F. Tilton                                  |
| United Air  Lines, Inc.                     |
| Chairman,  President and Chief Executive Officer |
| November 14,  2006                          |

 

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