**Exhibit 12.1**

**CERTIFICATIONS**

I, Klaus Heinemann,certify that:

1.                 I have reviewedthis annual report on Form 20-F of AerCap Holdings N.V.;

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(s) and I are responsible for establishing andmaintaining disclosure 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 thecompany and have:

(a)          Designed such disclosurecontrols and procedures, or caused such disclosure controls and procedures tobe designed under our supervision, to ensure that material information relatingto the company, including its consolidated subsidiaries, is made known to us byothers within those entities, particularly during the period in which thisreport is being prepared;

(b)         Designed such internalcontrol over financial reporting, or caused such internal control overfinancial reporting to be designed under our supervision, to provide reasonableassurance regarding the reliability of financial reporting and the preparationof financial statements for external purposes in accordance with generallyaccepted accounting principles;

(c)          Evaluated theeffectiveness of the company’s disclosure controls and procedures and presentedin this report our conclusions about the effectiveness of the disclosurecontrols and procedures, as of the end of the period covered by this reportbased on such evaluation; and

(d)         Disclosed in this reportany change in the company’s internal control over financial reporting thatoccurred during the period covered by the annual report that has materiallyaffected, or is reasonably likely to materially affect, the company’s internalcontrol over financial reporting;

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

(a)          All significantdeficiencies and material weaknesses in the design or operation of internalcontrol over financial reporting which are reasonably likely to adverselyaffect the company’s ability to record, process, summarize and report financialinformation; and

(b)         Anyfraud, whether or not material, that involves management or other employees whohave a significant role in the company’s internal control over financialreporting.
| Date: March 21, 2007     |   |   |   |
|--------------------------|--------|--------|--------|
| /s/ KLAUS HEINEMANN      |   |   |   |
| Signature                |   |   |   |
| Chief Executive  Officer |   |   |   |
| Title                    |   |   |   |

 

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