Exhibit 4.4.28

AMENDMENT No. 28

TO THE
A320 FAMILY PURCHASE AGREEMENT

BETWEEN

ATLANTIC AIRCRAFT HOLDING LIMITED

AND

AIRBUS S.A.S.



[***]   Represents
material which has been redacted and filed separately with the Securities and Exchange Commission pursuant to a request for confidential treatment pursuant to Rule 406 under the Securities Act of 1933, as amended

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This Amendment N°28 to the A320 Family Purchase Agreement dated as of March 19, 1998 (hereinafter
referred to as the Amendment N°28) between AIRBUS S.A.S. and ATLANTIC AIRCRAFT HOLDING LIMITED is made as of the
 day of October, 2013.

BETWEEN

AIRBUS S.A.S.,a société par actions simplifiée, formerly known as Airbus G.I.E. created and existing under French
law having its registered office at 1 Rond-Point Maurice Bellonte, 31707 Blagnac-Cedex, France and registered with the Toulouse Registre du Commerce under number RCS Toulouse 383 474 814 (hereinafter
referred to as the Seller)

AND

ATLANTIC
AIRCRAFT HOLDING LIMITED, having its principal office at c/o the Winterbotham Trust Company Limited, Winterbotham Place, Marlborough and Queen Streets. NASSAU, BAHAMAS (hereinafter referred to as the Buyer)

The Buyer and the Seller being together the Parties and each the Party.

WHEREAS



|A - | The Buyer and the Seller have entered into an A320 Family Purchase Agreement dated March 19, 1998 (hereinafter referred to, together with its Exhibits
and Letter Agreements as amended and supplemented from time to time, as the Purchase Agreement) covering the purchase by the Buyer and the sale by the Seller of thirty two (32) A320 Family Aircraft N°1 to N°32 (the
Aircraft).
|--- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|B - | The Buyer and the Seller have entered into an amendment N°1 to the Purchase Agreement dated September 9, 1998 (the Amendment N°
1), covering the [***]Firm A319-100 Aircraft (to December 1999 and January 2000).
|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|C - | The Buyer and the Seller have entered into an amendment n° 2 to the Purchase Agreement dated December 28, 1999 (the Amendment
N°2) covering :
|--- | -----------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | The [***]A320-200 Aircraft [***]and the [***]A320-200 Aircraft, and
| | --- | -------------------------------------------------------------------

| | (ii) | the [***]A320-200 Aircraft [***]A320-200 Aircraft.
| | ---- | --------------------------------------------------



|D - | [***]. Simultaneously, the Buyer and the Seller have entered into an amendment n° 3 (the Amendment N 3) to the Purchase
Agreement dated December 29, 1999 covering the modification of certain provisions of the Letter Agreement N°1 of the Purchase Agreement.
|--- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|E - | The Buyer and the Seller have entered into an amendment n°4 to the Purchase Agreement dated February 15, 2000 (the Amendment N°
4) covering:
|--- | ----------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the [***]A320-200 Aircraft [***]and its [***]A320-200 Aircraft, and
| | --- | -------------------------------------------------------------------

| | (ii) | the [***]A320-200 Aircraft [***]firm A319-100 Aircraft.
| | ---- | -------------------------------------------------------



|F - | The Buyer and the Seller have entered into amendment n°5 to the Purchase Agreement dated April 6, 2001 (the Amendment N°
5) covering:
|--- | ---------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the [***]A320-200 Aircraft [***] Firm N° 41) and the [***]A320-200 Aircraft (N° 44), and
| | --- | ----------------------------------------------------------------------------------------

| | (ii) | the [***]A320-200 Aircraft ([***]Firm N° 42) [***]Firm A319-100 Aircraft (Firm N° [***]
| | ---- | ---------------------------------------------------------------------------------------

| | (iii) | The [***]A320-200 Aircraft i[***] Firm N° 43) and the replacement of such Option by one (1) new Option A320-200 Aircraft (N° 46), and
| | ----- | -------------------------------------------------------------------------------------------------------------------------------------



[***]   Represents
material which has been redacted and filed separately with the Securities and Exchange Commission pursuant to a request for confidential treatment pursuant to Rule 406 under the Securities Act of 1933, as amended

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| | (iv) | the swap of one (1) Option A320-200 Aircraft [***]Firm N° 44) [***] Firm A319-100 Aircraft (Firm N[***]).
| | ---- | ---------------------------------------------------------------------------------------------------------



|G - | The Buyer and the Seller have entered into an amendment n° 6 to the Purchase Agreement dated April 9, 2001 (the Amendment N°6)covering the rescheduling of certain Delivery Dates related to firm Aircraft N°13, 14 and 40 (all of which were scheduled to be delivered in December 2001) which [***]firm Aircraft N°45 (September 2001), N°46 (October 2001) and
N°47 (October 2001) and additionally firm Aircraft N°18 [***]to an A320-200 Aircraft type.
|--- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|H - | [***]
|--- | -----



|I - | [***]
|--- | -----



|J - | The Buyer and the Seller have entered into amendment n° 9 to the Purchase Agreement dated December 6, 2002 (the Amendment
N°9) covering the rescheduling of the Delivery Date of the firm Aircraft N°22 from August 2003 to June 2003.
|--- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|K - | The Buyer and the Seller have entered into amendment n° 10 to the Purchase Agreement dated October 30, 2003 (the Amendment N°10)covering the rescheduling of the Delivery Date of firm A320-200 Aircraft N°46 and 47 respectively from May and June 2004 to October and November 2004.
|--- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|L - | The Buyer and the Seller have entered into an amendment n° 11 to the Purchase Agreement dated November 18, 2004 (the Amendment
N°11) covering simultaneously:
|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the termination of the [***], and
| | --- | ---------------------------------

| | (ii) | the cancellation and termination of Amendment N°3 i[***] stated in paragraph 1 of Letter Agreement N°1 to the Purchase Agreement.
| | ---- | ---------------------------------------------------------------------------------------------------------------------------------



|M - | The Buyer and the Seller have entered into an amendment n° 12 to the Purchase Agreement dated November 18, 2004 (the Amendment
N°12) covering:
|--- | ------------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the [***] of Aircraft N°44, 17, 37[***]A320 [***]A321 type and N°18, 36 and 21 [***]A320 [***]A319 [***],
| | --- | ---------------------------------------------------------------------------------------------------------

| | (ii) | [***],
| | ---- | ------

| | (iii) | [***].
| | ----- | ------



|N - | The Buyer and the Seller have entered into an amendment n° 13 to the Purchase Agreement dated November 18, 2004 (the Amendment
N°13), covering:
|--- | -------------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | [***].
| | --- | ------



|O - | The Buyer and the Seller have entered into amendment n° 14 to the Purchase Agreement dated February 28, 2006 (the Amendment
N°14), covering:
|--- | ----------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | [***]AIRMAN software,
| | --- | ---------------------

| | (ii) | ADOC Job Cards Package, ADOC Consultation Package, and AirN@v and/or ADOC N@vigator Based Consultation
| | ---- | ------------------------------------------------------------------------------------------------------

| | (iv) | [***].
| | ---- | ------



|P - | The Buyer and the Seller have entered into amendment n° 15 to the Purchase Agreement dated June 22, 2007 (the Amendment
N°15), covering:
|--- | ------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | [***].
| | --- | ------



[***]   Represents
material which has been redacted and filed separately with the Securities and Exchange Commission pursuant to a request for confidential treatment pursuant to Rule 406 under the Securities Act of 1933, as amended

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|Q - | The Buyer and the Seller have entered into amendment n° 16 to the Purchase Agreement dated November 22, 2007 (the Amendment
N°16), covering the order of [***] A319-100 aircraft and [***])A320-200 aircraft.
|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|R - | The Buyer and the Seller have entered into amendment n° 17 to the Purchase Agreement dated
April 1st, 2008 (the Amendment N°17), to amend certain provisions of the [***].
|--- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|S - | The Buyer and the Seller have entered into amendment n° 18 to the Purchase Agreement dated
January 30th, 2009 (the Amendment N°18), covering:
|--- | -----------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the rescheduling of the Delivery Dates of the Aircraft N°60 and 61,
| | --- | -------------------------------------------------------------------

| | (ii) | [***]T - The Buyer and the Seller have entered into amendment n° 19 to the Purchase Agreement dated April 28th, 2009 (the Amendment N°19), covering:
| | ---- | ------------------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the [***]of the Aircraft N°58, 62 and 65,
| | --- | -----------------------------------------

| | (ii) | the change of the Delivery Dates of the Aircraft N°58, 62 and 65,
| | ---- | -----------------------------------------------------------------



|U - | The Buyer and the Seller have entered into amendment n° 20 to the Purchase Agreement dated
February 10th, 2010 (the Amendment N°20), covering:
|--- | ------------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the rescheduling of the Delivery Dates of the Aircraft N°58 and 65,
| | --- | -------------------------------------------------------------------

[***].



|V - | The Buyer and the Seller have entered into amendment n°21 to the Purchase Agreement dated 29 April, 2011 (the Amendment
N°21), covering the [***]of the Aircraft N°64.
|--- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|W - | The Buyer and the Seller have entered into amendment n°22 to the Purchase Agreement dated 26 August, 2011 (the Amendment
N°22), covering:
|--- | -------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the rescheduling of the Delivery Date of Aircraft N° 61,
| | --- | --------------------------------------------------------

| | (ii) | the [***]and the rescheduling of the Delivery Dates of Aircraft N°66 and 67.
| | ---- | ----------------------------------------------------------------------------



|X - | The Buyer and the Seller have entered into amendment n°23 to the Purchase Agreement dated 25 October, 2011 (the Amendment
N°23), covering:
|--- | --------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the rescheduling of the Delivery Date of Aircraft N° 58,
| | --- | --------------------------------------------------------

| | (ii) | the [***]and the rescheduling of the Delivery Dates of Aircraft N°68 and 69.
| | ---- | ----------------------------------------------------------------------------



|Y - | The Buyer and the Seller have entered into amendment n°24 to the Purchase Agreement dated 29 March, 2012 (the Amendment
N°24), covering:
|--- | ------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the rescheduling of the Delivery Date of Aircraft N° 65,
| | --- | --------------------------------------------------------

| | (ii) | the [***]and the rescheduling of the Delivery Dates of Aircraft N°60, 70, 71, 72, 73, 74, 75 and 76.
| | ---- | ----------------------------------------------------------------------------------------------------



|Z - | The Buyer and the Seller have entered into amendment n°25 to the Purchase Agreement dated 29 March, 2012 (the Amendment
N°25), covering:
|--- | ------------------------------------------------------------------------------------------------------------------------------------------

[***]



[***]   Represents
material which has been redacted and filed separately with the Securities and Exchange Commission pursuant to a request for confidential treatment pursuant to Rule 406 under the Securities Act of 1933, as amended

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|AA - | The Buyer and the Seller have entered into amendment n°26 to the Purchase Agreement dated 29 March, 2012 (the Amendment
N°26), covering:
|---- | ------------------------------------------------------------------------------------------------------------------------------------------

| | (i) | the equipment of certain Aircraft with Sharklets
| | --- | ------------------------------------------------

| | (ii) | [***]
| | ---- | -----



|AB - | The Buyer and the Seller have entered into amendment n°27 to the Purchase Agreement dated 30 November, 2012 (the Amendment
N°27), covering the [***] of the Aircraft N°60 [***]
|---- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|AC - | The Seller has requested the Buyer to use one aircraft for specific tests and the Buyer has agreed to such tests under the terms and conditions of this
Amendment N°28.
|---- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------



|AC - | As used hereafter, the terms Purchase Agreement and A320 Family Purchase Agreement mean the Purchase Agreement together
with all Exhibits and schedules thereto as amended to date by Amendments N°1 to 27, inclusive.
|---- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

NOW THEREFORE IT IS AGREED AS FOLLOWS:



[***]   Represents
material which has been redacted and filed separately with the Securities and Exchange Commission pursuant to a request for confidential treatment pursuant to Rule 406 under the Securities Act of 1933, as amended

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|1. | [***]TESTING
|-- | ------------



|1.1 | The Buyer hereby acknowledges and agrees that the [***]Aircraft bearing [***]) will be used by the Seller prior to Delivery for the purpose [***]tests for
[***]Aircraft including the new [***]).
|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|1.2 | The Buyer and the Seller furthermore acknowledge and agree that, as a result of the [***] being used for the purpose of the [***], the Seller will provide
the Buyer with a [***] compensation based on the actual use by the Seller of the [***]for the specific purpose of achieving the [***]Testing as follows:
|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | - | a [***], and
| | - | ------------

| | - | a [***] of use by the Seller.
| | - | -----------------------------

Notwithstanding the above, the Buyer hereby acknowledges and agrees that such compensation, subject to an aircraft utilization
[***][***]).

Such compensation shall be made available to the Buyer upon Delivery of [***] and applied against the Final Price of
the [***], or may be used for the purchase of goods and services from the Seller.



|2. | [***]
|-- | -----



| | 2.1 | [***]
| | --- | -----

|2.2 | [***]subject to:
|--- | ----------------

a)
The Purchase Agreement being in full force and effect; and,

b) The Buyer not being in default under the Purchase Agreement and
being current, among other obligations, on any and all of its Predelivery Payments obligations.

[***]



[***]   Represents
material which has been redacted and filed separately with the Securities and Exchange Commission pursuant to a request for confidential treatment pursuant to Rule 406 under the Securities Act of 1933, as amended

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|3. | MISCELLANEOUS
|-- | -------------

It is hereby agreed that all terms and conditions of the Purchase Agreement, as amended hereby, including its Exhibits and Letter
Agreements shall remain in full force and effect and shall apply to this Amendment N°28 except as expressly modified by this Amendment N°28.

In case of any inconsistency between this Amendment N°28 and the Purchase Agreement, this Amendment N°28 shall prevail.

This Amendment N°28 together with the Purchase Agreement, its Exhibits, Letter Agreements, and amendments to date contain the entire
agreement between the Parties with respect to the subject matter hereof and supersede any previous understandings, commitments and/or representations whatsoever oral and written with respect to such subject matter.

This Amendment N°28 is executed in two original English counterparts, each of which is an original and both of which together
evidence the same agreement. This Amendment N°28 shall not be varied or modified except by an instrument in writing executed by both Parties or by their duly authorised representatives.

This Amendment N°28 shall be governed by and construed and performance thereof shall be determined in accordance with the laws of
France.

The Amendment N° 28 (and its existence) shall be treated by each Party as confidential and shall not be released or
revealed in whole or in part to any third party without the prior written consent of the other Party. In particular, each Party agrees not to make any press release concerning the whole or any part of the contents and/or subject matter hereof or of
any future addendum hereto without the prior written consent of the other Party.

This Amendment N°28 may be executed by the
Parties in separate counterparts and any single counterpart shall be deemed to be an original and a set of such counterparts executed and delivered by the Parties shall constitute one and the same Amendment N°28 and a full original Amendment
N°28 for all purposes.



[***]   Represents
material which has been redacted and filed separately with the Securities and Exchange Commission pursuant to a request for confidential treatment pursuant to Rule 406 under the Securities Act of 1933, as amended

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IN WITNESS WHEREOF this Amendment N°28 was entered into the day and
year above written.



ATLANTIC AIRCRAFT HOLDING

AIRBUS S.A.S.LIMITEDBy :

By :Its :

Its




[***]   Represents
material which has been redacted and filed separately with the Securities and Exchange Commission pursuant to a request for confidential treatment pursuant to Rule 406 under the Securities Act of 1933, as amended

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