SUPPLEMENTAL AGREEMENT NO. 4 to Purchase AgreementNo. 3219 between THE BOEING COMPANY and AMERICAN AIRLINES, INC. Relating to Boeing Model 787 Aircraft

Exhibit 10.6

SUPPLEMENTAL AGREEMENT NO. 4

to

Purchase Agreement No. 3219

between

THE BOEING COMPANY

and

AMERICAN AIRLINES, INC. Relating

to Boeing Model 787 Aircraft

THIS SUPPLEMENTAL AGREEMENT No. 4 (SA-4) is made between THE BOEING COMPANY, a Delaware corporation with offices in Seattle, Washington, (Boeing), and AMERICAN AIRLINES, INC, a Delaware corporation with offices in Fort Worth, Texas, together with its successors and permitted assigns (Customer);

Boeing and Customer entered into Purchase Agreement No. 3219 dated October 15, 2008, relating to Boeing Model 787 aircraft, as amended and supplemented (Purchase Agreement) and capitalized terms used herein without definitions shall have the meanings specified therefore in such Purchase Agreement;

[*CTR] the [*CTR] of four (4) Boeing Model [*CTR] aircraft ([*CTR] Aircraft) in lieu of four (4) Boeing Model [*CTR] aircraft. Boeing is [*CTR] to provide the [*CTR] Aircraft for delivery to Customer in [*CTR] 2015, [*CTR] 2016, [*CTR] 2016, and [*CTR] 2016. [*CTR];

Customer and Boeing have previously executed documents amending the Purchase Agreement to reflect Customer’s acceptance of [*CTR] (Package A), [*CTR] (Package B), [*CTR] (Package C), [*CTR] (Package D), [*CTR] (Package E), [*CTR] (Package F) and [*CTR] (Package G) (Customer’s acceptance of [*CTR] reflected in Package A, Package B, Package C, Package D, Package E, Package F and Package G mutually agreed to comprise Customer [*CTR] Changes) for [*CTR] aircraft (Customer [*CTR] Aircraft). [*CTR] changes to any [*CTR] Aircraft will be undertaken in the ordinary course of business with Boeing by Customer. With respect to such Customer [*CTR] Changes, Customer and Boeing now agree to replace the existing Exhibit A2 with a revised Exhibit A2 [*CTR] aircraft.

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NOW, THEREFORE, the parties agree that the Purchase Agreement is amended as set for the below and otherwise agree as follows:

1. Table of Contents.

Remove and replace, in its entirety, the current Table of Contents with the new Table of Contents (attached hereto), to reflect the incorporation of this SA-4 into the Purchase Agreement.

2. Tables.

2.1 Table 1(R2) entitled “787-9 Aircraft Delivery, Description, Price and Advance Payments” is revised by this SA-4, to recognize that with the execution of this SA-4 the following will occur: i) the deletion of four (4) [*CTR] Aircraft ([*CTR] 2015, [*CTR] 2016, and [*CTR] ([*CTR]) [*CTR] 2016) due to [*CTR] of the [*CTR] Aircraft into [*CTR] Aircraft; and ii) the [*CTR] ([*CTR]) [*CTR] ([*CTR] 2016 to [*CTR] 2016, and [*CTR] 2016 to [*CTR] 2016).

2.2 Table 3 entitled “787-8 Aircraft Delivery, Description, Price and Advance Payments – Four (4) [*CTR] Aircraft” is added to set forth the [*CTR] 787-8 Aircraft.

2.3 Each reference in the Purchase Agreement, and the exhibits, supplemental exhibits and letter agreement thereto, to “Aircraft” shall be deemed to include the [*CTR] Aircraft. Additionally, references in the Purchase Agreement, and the exhibits, supplemental exhibits and letter agreement thereto, to Table 1R2 and/or Table 2 are deemed, unless the context suggests otherwise, to refer to Table 3 as well.

3. Supplemental Exhibits.

Supplemental Exhibit EE2 entitled “[*CTR]” is added to set forth [*CTR] that is applicable to the [*CTR] Aircraft.

4. Exhibits.

Exhibit A2 is replaced in its entirety with Exhibit A2R1 which references this SA-4 to [*CTR] the Customer [*CTR] Changes for each Customer [*CTR] Aircraft.

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5. [*CTR].

In accordance with Section [*CTR] of Letter Agreement 6-1162-TRW-0664R1, Aircraft Purchase Rights and Substitution Rights, Boeing shall promptly [*CTR] to Customer the [*CTR] of [*CTR] (as defined in the Letter Agreement) [*CTR] by Customer [*CTR] with respect to the [*CTR].

6. Effect on Purchase Agreement.

Except as expressly set forth herein, all terms and provisions contained in the Purchase Agreement shall remain in full force and effect. This Agreement contains the entire agreement between the parties with respect to the subject matter hereof and supersedes all previous proposals, and agreements, understandings, commitments or representations whatsoever, oral or written, with respect to the subject matter hereof and may be changed only in writing signed by authorized representatives of the parties.

The Engine Price reflected in Table 3, [*CTR] applicable to each 787-8 Aircraft, is [*CTR] upon the [*CTR] in [*CTR] (including, but not limited to, the [*CTR]). In executing SA-4, each of the parties [*CTR].

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TABLE OF CONTENTS

BOEING PROPRIETARY

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TABLE OF CONTENTS, continued

BOEING PROPRIETARY

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TABLE OF CONTENTS, continued

BOEING PROPRIETARY

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Table 3 To

Purchase Agreement No. PA-03219

787-8 Aircraft Delivery, Description, Price and Advance Payments—Four (4) [*CTR] Aircraft

Total: 4

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AIRCRAFT CONFIGURATION

between

THE BOEING COMPANY

and

AMERICAN AIRLINES, INC.

Exhibit A2(R1) to Purchase Agreement Number 3219

Exhibit A2(R1) to Purchase Agreement Number 3219

AIRCRAFT CONFIGURATION

relating to

BOEING MODEL 787-8 AIRCRAFT

1. [*CTR]

[*CTR]

[*CTR]

BOEING PROPRIETARY

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BOEING PROPRIETARY

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BOEING PROPRIETARY

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BOEING PROPRIETARY

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BOEING PROPRIETARY

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[*CTR]

between

THE BOEING COMPANY

and

AMERICAN AIRLINES, INC.

Supplemental Exhibit EE2

to Purchase Agreement Number 3219

BOEING PROPRIETARY

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[*CTR]

relating to

SUBSTITUTE 787-8 AIRCRAFT

[*CTR]

[*CTR]

[*CTR]

[*CTR]

[*CTR]

[*CTR]

[*CTR]

[*CTR]

[*CTR]

BOEING PROPRIETARY

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[*CTR]

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[*CTR]

NOTE:

(i) [*CTR]

(ii) [*CTR]

(iii) [*CTR]

(iv) [*CTR]

(v) [*CTR]

(vi) [*CTR]

BOEING PROPRIETARY

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2. Values to be Utilized in the Event of Unavailability.

2.1 [*CTR]

2.2 [*CTR]

2.3 [*CTR]

2.4 [*CTR]

NOTE:

(i) [*CTR]

BOEING PROPRIETARY

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(ii) [*CTR]

3. [*CTR]

3.1 [*CTR]

[*CTR]

3.2 [*CTR]

BOEING PROPRIETARY

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