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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 ofUnited Air Lines, Inc. (the "Company"), certify that:(1)     I have reviewed this quarterly reporton Form 10-Q for the period ended March 31, 2006 of the Company;
(2)     Based on my knowledge, this report doesnot contain any untrue statement of a material fact or omit to state amaterial fact necessary to make the statements made, in light of the circumstancesunder which such statements were made, not misleading with respect to theperiod covered by this report;
(3)     Based on my knowledge, the financial statements,and other financial information included in this report, fairly presentin all material respects the financial condition, results of operationsand cash flows of the Company as of, and for, the periods presented inthis report;
(4)     The Company's other certifying officer andI are responsible for establishing and maintaining disclosure controlsand procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e))and internal control over financial reporting (as defined in Exchange ActRules 13a-15(f) and 15d-15(f)) for the Company and have: (a)     Designed such disclosure controls andprocedures, or caused such disclosure controls and procedures to be designedunder our supervision, to ensure that material information relating tothe Company, including its consolidated subsidiaries, is made known tous by others within those entities, particularly during the period in whichthis report is being prepared;
(b)     Designed such internal control over financialreporting, or caused such internal control over financial reporting tobe designed under our supervision, to provide reasonable assurance regardingthe reliability of financial reporting and the preparation of financialstatements for external purposes in accordance with generally acceptedaccounting principles;
(c)     Evaluated the effectiveness of the Company'sdisclosure controls and procedures and presented in this report our conclusionsabout the effectiveness of the disclosure controls and procedures, as ofthe end of the period covered by this report based on such evaluation;and
(d)     Disclosed in this report any change in theCompany's internal control over financial reporting that occurred duringthe Company's most recent fiscal quarter that has materially affected,or is reasonably likely to materially affect, the Company's internal controlover financial reporting; and (5)     The Company's other certifying officer andI have disclosed, based on our most recent evaluation of internal controlover financial reporting, to the Company's auditors and the audit committeeof Company's board of directors (or persons performing the equivalent functions):(a)     All significant deficiencies and materialweaknesses in the design or operation of internal control over financialreporting which are reasonably likely to adversely affect the Company'sability to record, process, summarize and report financial information;and
(b)     Any fraud, whether or not material, thatinvolves management or other employees who have a significant role in theCompany's internal control over financial reporting.   /s/ Glenn F. Tilton__________Glenn F. TiltonUnited Air Lines, Inc.Chairman, President and Chief Executive OfficerMay 15, 2006  

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