<PAGE>

                                                                   EXHIBIT 10.12

                                                               EXECUTION VERSION

                    SECURITY TRUSTEE AGREEMENT [SPARE PARTS]

                          Dated as of September 3, 2004

                                     between

                           WELLS FARGO BANK NORTHWEST,
                              NATIONAL ASSOCIATION
                         not in its individual capacity,
                       except as expressly stated herein,
                         but solely as Security Trustee

                                       and

                    THE PERSONS NAMED HEREIN AS BENEFICIARIES

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                                    Page
<S>               <C>                                                                                               <C>
SECTION 1.        Definitions.....................................................................................   1

SECTION 2.        Authorization and Action........................................................................   1

SECTION 3.        Limitation on Liability.........................................................................   2

SECTION 4.        Resignation and Removal.........................................................................   3

SECTION 5.        Action by Security Trustee Upon Request of Beneficiaries........................................   4

SECTION 6.        Security Trustee Entitled to Receive Opinion of Security Trustee's Counsel......................   5

SECTION 7.        Compensation....................................................................................   5

SECTION 8.        Appointment of Security Co-Trustee(s)...........................................................   5

SECTION 9.        Trust Company Representations and Warranties....................................................   5

SECTION 10.       Distributions...................................................................................   6

SECTION 11.       Miscellaneous...................................................................................   7
</TABLE>

Schedule 1 - Beneficiaries

Schedule 2 - Addresses for Notice

                                      (i)

<PAGE>

      THIS SECURITY TRUSTEE AGREEMENT [SPARE PARTS] (the "Security Trustee
Agreement") is dated as of September 3, 2004, between Wells Fargo Bank
Northwest, National Association, not in its individual capacity, except as
expressly stated herein, but solely as Security Trustee (the "Security Trustee")
and the Persons named as Beneficiaries on Schedule 1 hereto (together with
Affiliates, their respective successors and assigns, collectively, the
"Beneficiaries" and each a "Beneficiary").

      WHEREAS:

      A. Reference is hereby made to the Payment and Indemnity Agreement [Spare
Parts] dated as of the date hereof (the "AWA Payment & Indemnity Agreement") of
America West Airlines, Inc. (the "Obligor") in favor of the Beneficiaries and
the Security Trustee.

      B. Reference is hereby made to the Subordinated Spare Parts Mortgage and
Security Agreement and the related supplements entered into on or after the date
hereof (the "Mortgage") by the Obligor in favor of the Security Trustee with
respect to the Collateral.

      NOW, THEREFORE, in consideration of the agreements herein and in reliance
upon the representations and warranties set forth herein and therein, the
parties agree as follows:

      SECTION 1. Definitions. Unless otherwise defined herein, all capitalized
terms used but not defined herein have the meanings assigned to such terms in
the Mortgage or the Payment & Indemnity Agreement. The following terms, as used
herein, have the following meanings:

      "Collateral" means the Pledged Spare Parts and such other items as are set
forth in Section 2.01 of the Mortgage (and any replacements thereto pursuant to
the terms of the Mortgage).

      "Event of Default" has the meaning assigned to such term in the Mortgage.

      "Operative Documents" means this Security Trustee Agreement, the Payment &
Indemnity Agreement and the Mortgage.

      "Person" has the meaning assigned to in the Mortgage.

      "Required Beneficiaries" means General Electric Capital Corporation or its
successors or assigns.

      SECTION 2. Authorization and Action. (a) Each Beneficiary hereby appoints
the Security Trustee as its security trustee and agent and authorizes the
Security Trustee to take such action as the Security Trustee on such
Beneficiary's behalf and to exercise such powers under this Security Trustee
Agreement, the other Operative Documents as are delegated to the Security
Trustee by the terms hereof and thereof, together with such powers as are
reasonably incidental thereto. The Security Trustee hereby accepts such
appointment. As to any matters not

<PAGE>

expressly provided for by this Security Trustee Agreement and the other
Operative Documents, the Security Trustee shall not be required to exercise any
discretion or take any action, but shall be required to act or to refrain from
acting (and shall be fully protected in so acting or refraining from acting)
upon the instructions of the Required Beneficiaries, and such instructions shall
be binding upon all Beneficiaries; provided, however, that the Security Trustee
shall not be required to take any action which exposes the Security Trustee to
personal liability or which is contrary to this Security Trustee Agreement or
applicable Law. The Security Trustee agrees to give to each Beneficiary (or its
designated agent) prompt notice of each notice given to it pursuant to any
Operative Document.

      (b) No trust relationship between the Security Trustee and the
Beneficiaries, nor any other Person, is created or intended to be created by
this Security Trustee Agreement rather the Security Trustee is solely the agent
of the Beneficiaries for purposes of the collateral granted pursuant to the
Mortgage which secures the obligations of Obligor under the Operative Documents.
The Security Trustee shall have only those powers, duties and obligations as are
expressly set forth in the Operative Documents.

      SECTION 3. Limitation on Liability. (a) Except for the liability of Wells
Fargo Bank Northwest, National Association (the "Trust Company") for the Trust
Company's representations and warranties in Section 9, and for its own gross
negligence and willful misconduct, it is expressly understood and agreed by the
parties hereto that (i) this Security Trustee Agreement is executed and
delivered by the Trust Company, not in its individual capacity but solely as
Security Trustee in the exercise of the powers and authority conferred and
vested in it as the Security Trustee, (ii) nothing herein contained shall be
construed as creating any liability on the Trust Company, individually or
personally, to perform any obligation of the Security Trustee either expressed
or implied contained herein or in the Operative Documents, all such liability,
if any, being expressly waived by the parties to this Security Trustee Agreement
and by any Person claiming by, through or under the parties to this Security
Trustee Agreement and (iii) under no circumstances shall the Trust Company be
personally liable for the payment of any indebtedness or expenses of the
Security Trustee or be liable for the breach or failure of any obligation,
representation, warranty or covenant made or undertaken by the Security Trustee
under this Security Trustee Agreement and the other Operative Documents.

      (b) The recitals and preliminary statements in the Operative Documents
shall be taken as statements by the party or parties thereto (other than the
Security Trustee), and shall not be considered as made by, or as imposing any
obligation or liability upon, the Security Trustee, nor shall the Security
Trustee be held responsible for the value of the Collateral or for the legality
or validity of the Operative Documents, any supplement to any of the above or
any instrument of further assurance except that, as to each of the above to
which the Security Trustee is a party, it is executed and delivered by the
Security Trustee, and that the officer or officers executing and delivering the
same have been duly authorized to do so on behalf of the Security Trustee. No
representation or warranty respecting the rights or remedies of the
Beneficiaries, the Security Trustee's right, title, interest, claim or demand in
or to the Collateral or the condition thereof or the sufficiency of the security
for the Operative Documents is made or implied by the Security Trustee's
execution and delivery hereof or any Operative Document.

                                       2

<PAGE>

      (c) Whenever pursuant to the terms of this Security Trustee Agreement or
the Operative Documents, the Security Trustee is obliged to distribute any sum
of money to the registered Beneficiaries or to any other Person, it is
understood that such obligations are undertaken by it in its capacity as
Security Trustee hereunder, and not in its individual capacity, and that such
payment and disbursement are to be made only from the income and proceeds of any
Collateral and any other security granted pursuant to the Operative Documents
and only to the extent that the Security Trustee has in its hands sufficient
income or proceeds from such Collateral or other security to make such payment
or distribution.

      (d) The Security Trustee shall not be required to take notice or be deemed
to have knowledge of any Event of Default, unless the Security Trustee shall
have actual knowledge thereof or shall receive from a Beneficiary, notice
stating that the same has occurred and is continuing, and specifying the same,
and in the absence of such notice the Security Trustee may conclusively assume
that the same does not exist, except as aforesaid.

      (e) The Security Trustee shall not be subject to any liability whatsoever
to a Beneficiary or any other Person, in tort, contract or otherwise, in
connection with any matter arising from the exercise by the Security Trustee of
any powers or authorities conferred hereunder or for the acts, omissions,
receipts, neglects or defaults of any Person employed or engaged by it as
permitted hereunder or for any loss or damage occasioned by an error in judgment
or oversight on the part of the Security Trustee, or for any other loss, damage
or misfortune which may occur in the execution by the Security Trustee of its
duties hereunder, except for that arising from the Security Trustee's gross
negligence, willful misconduct or bad faith.

      SECTION 4. Resignation and Removal. (a) The Security Trustee may resign
and be discharged hereunder at any time, without cause, by giving at least
thirty (30) days' notice of such resignation to the Obligor and each
Beneficiary, such resignation to be effective on the date specified in the
notice; provided, however that such resignation shall not be effective until a
successor Security Trustee shall have been appointed pursuant to the provisions
below. In addition, the Security Trustee may be removed at any time without
cause by an instrument or concurrent instruments signed by the Required
Beneficiaries, or by their attorneys-in-fact thereunto duly authorized, and
delivered to each Beneficiary. In case of the resignation or removal of the
Security Trustee, or if the Security Trustee shall otherwise become incapable of
acting or shall be taken under the control of any public officer or officers or
of a receiver appointed by a court, then a successor or successors may be
appointed by the Required Beneficiaries; provided that, so long as no Default
shall have occurred and be continuing, such successor or successors shall be
reasonably acceptable to the Obligor. If such Required Beneficiaries shall fail
to make such appointment prior to the date such resignation, removal or other
incapacity is effective, then the Security Trustee or any registered Beneficiary
may request a court of competent jurisdiction to appoint such successor to act
until such time, if any, as a successor shall have been appointed as provided
above. Any successor Security Trustee so appointed by such court shall
immediately and without further act be superseded by a successor Security
Trustee appointed as above provided.

      (b) Upon the acceptance of any appointment as Security Trustee under this
Security Trustee Agreement by a successor Security Trustee, such successor
Security Trustee

                                       3

<PAGE>

shall become vested with all the rights, remedies, duties, obligations and
powers of such predecessor with like effect as if originally named herein as
Security Trustee.

      (c) Any successor to the Security Trustee, however constituted, shall be a
bank or trust company organized and existing under the laws of the United States
of America or any state thereof or organized and having capital funds as of the
date of appointment of such successor (as shown by its most recent financial
statements distributed to its shareholders) aggregating at least US$500,000,000,
if there shall be such a bank or trust company willing and legally qualified to
accept and perform the trusts hereunder and the duties mentioned herein upon
reasonable or customary terms.

      (d) Any Person into which the Security Trustee may be merged or with which
it may be consolidated, any corporation resulting from any merger or
consolidation or conversion to which the Security Trustee shall be a party or
any corporation to which all or substantially all of the corporate trust
business of the Security Trustee may be transferred (whether by operation of Law
or otherwise), shall be the successor to the Security Trustee under this
Security Trustee Agreement without the execution or filing of any paper or any
further act on the part of any of the parties hereto; provided, however, that
notice of the same is given to each Beneficiary, and that any such Person meets
the requirements set forth in Section 4(c).

      SECTION 5. Action by Security Trustee Upon Request of Beneficiaries. (a)
Upon the written request of the Required Beneficiaries, the Security Trustee
shall give its consent to, or take, any action so requested or change under, in
or in respect of the Collateral or the Operative Documents.

      (b) The Security Trustee may decline to follow any such request if (i) the
Security Trustee shall receive an opinion of its counsel to the effect that such
consent or such action or change may not lawfully be made or taken, or (ii) the
Security Trustee shall determine in good faith that such consent or such action
or change would subject the Security Trustee to the risk of any personal
liability or any expense, unless (in cases not involving criminal liability) any
of the Beneficiaries can and do indemnify and hold the Security Trustee
harmless, in form and amount reasonably satisfactory to the Security Trustee,
from and against such liability or expense and provide the Security Trustee with
sufficient funds to cover its expenses with respect to such action.

      (c) The Security Trustee shall not incur any liability to anyone in acting
upon any signature, instrument, notice, resolution, request, consent, order,
certificate, report, opinion, note or other document or paper reasonably
believed by it to be genuine and the Security Trustee shall not be obliged to
make any investigation or inspection to verify the correctness or completeness
of the facts stated in any of the foregoing papers or documents. In the
administration of its duties under the Operative Documents, the Security Trustee
may act directly or through its agents or attorneys and may consult with
counsel, appraisers, engineers, accountants, and other skilled persons to be
selected and employed by it, and the Security Trustee shall not be liable for
anything done, suffered or omitted in good faith by it in accordance with the
advice of any thereof.

                                       4

<PAGE>

      SECTION 6. Security Trustee Entitled to Receive Opinion of Security
Trustee's Counsel. The Security Trustee shall, before taking any action in
respect of an Event of Default, be entitled to receive (if requested by the
Security Trustee) at least five (5) days' prior notice of the action to be taken
and of the form of the instruments involved and an opinion of Security Trustee's
counsel, in form and substance satisfactory to the Security Trustee, stating the
legal effect of such action, the steps necessary to be taken to consummate such
action and that such action will not impair the security for the Beneficiaries
in contravention of the provisions hereof, and such opinion shall be full
protection to the Security Trustee in reliance thereon.

      SECTION 7. Compensation. The Security Trustee shall be entitled to
reasonable compensation ratably from the Obligor for its services and
reimbursement ratably by the Obligor for all proper disbursements of every sort
and nature incurred by it, including reasonable fees and expenses of the
Security Trustee's counsel and appraisers, engineers, accountants and other
skilled persons properly employed by the Security Trustee, pursuant to terms
hereof, the Operative Documents or in taking any action upon an Event of Default
or in instituting, appearing in or defending any proceeding with respect thereto
and for all other expenses incurred by it hereunder and for all taxes which may
be assessed against the Security Trustee as such or against any funds on deposit
with the Security Trustee and for all statutory penalties and other payments
which the Security Trustee may be required to pay or make; provided, however,
that the Security Trustee shall not be entitled to compensation or
reimbursements if such disbursements are necessary as the result of the Security
Trustee's own bad faith, gross negligence or willful misconduct.

      SECTION 8. Appointment of Security Co-Trustee(s). At any time or times, in
order to comply with any legal requirement in any jurisdiction, the Security
Trustee may, and if directed in writing by the Required Beneficiaries shall,
appoint another bank or trust company or one or more other Persons, either to
act as security co-trustee(s), jointly with the Security Trustee, or to act as
separate security trustee(s) on behalf of the Beneficiaries. The Security
Trustee shall be not personally liable by reason of any act or omission of any
such security trustee(s) or security co-trustee(s), as the case may be,
appointed under this Section 8, if the Required Beneficiaries have approved the
appointment of such security trustee(s) or security co-trustee(s), as the case
may be.

      SECTION 9. Trust Company Representations and Warranties. The Trust
Company, in its individual capacity and not as Security Trustee, hereby
represents and warrants to each Beneficiary that the following shall be true and
correct on and as of the date first above written (unless otherwise specified):

      (a) Powers and Authorizations. It is a national banking association duly
organized and validly existing in good standing under the laws of the United
States and has full power and authority, in its individual capacity, to execute
and deliver this Security Trustee Agreement and (assuming the due authorization,
execution and delivery of this Agreement by the other parties hereto) perform
its obligations hereunder. The execution, delivery and performance by the
Security Trustee of the Operative Documents to which it is or will be a party
have been duly authorized by all necessary action on its part and do not
contravene the Charter or By-laws of the Security Trustee; and the Operative
Documents to which the Security Trustee is or will be a party have been duly
authorized, executed and delivered by the Security Trustee and constitute

                                       5

<PAGE>

the legal, valid and binding obligations, enforceable against it in accordance
with its terms. This Security Trustee Agreement and the other Operative
Documents to which the Security Trustee is or will be a party, upon the due
execution and delivery hereof, will constitute the legal, valid and binding
obligations of the Security Trustee in its individual capacity, and the
performance by the Security Trustee (in its individual or trust capacity, as the
case may be) of any of its obligations hereunder and thereunder does not
contravene any federal law or regulation or contractual restriction binding on
or governing the banking or trust powers of the Security Trustee (in its
individual or trust capacity, as the case may be);.

      (b) Pending Litigation. There are no pending (or, to the Security
Trustee's knowledge, threatened) actions, suits, investigations or proceedings
against or affecting it before any court, arbitrator, or administrative or
governmental body which, individually or in the aggregate, if decided adversely
to the interests of the Security Trustee would materially and adversely affect
the ability of the Security Trustee, either in its individual capacity or as
Security Trustee, as the case may be, to perform its obligations under this
Security Trustee Agreement or any other Operative Document or which questions or
would affect the legality or validity of this Security Trustee Agreement or such
Operative Document; and

      (c) No Legal Bar. Neither the execution and delivery by the Security
Trustee of this Security Trustee Agreement or any other Operative Document nor
the consummation by the Security Trustee of any of the transactions contemplated
hereby or thereby requires or will require the consent or approval of or the
giving of notice to, the registration with, or the taking of any other action in
respect of, any federal or governmental authority or agency governing its
banking or trust powers.

      SECTION 10. Distributions. (a) Any time and from time to time, any
Beneficiary may give notice to the Security Trustee substantially in the form of
Annex A hereto.

      (b) Within 10 days following receipt by the Security Trustee of a notice
from a Beneficiary substantially in the form of Annex A hereto, the Security
Trustee shall send a notice to each Beneficiary substantially in the form of
Annex B hereto.

      (c) Within 30 days of receipt of a notice from the Security Trustee
substantially in the form of Annex B hereto each Beneficiary shall certify to
the Security Trustee in writing the full amount then owing to such Beneficiary
under any of the Operative Documents. The Security Trustee may rely on such
certifications for the purposes of this Section 10.

      (d) Upon the occurrence of an Event of Default, after deducting all
amounts owing to the Security Trustee for compensation, reimbursement of
expenses and indemnity, including, without limitation, its reasonable
compensation and expenses for the services of attorneys, servants and agents of
Security Trustee properly engaged and employed (including compensation and
expenses in connection with any appeal), the Security Trustee shall apply the
moneys received by it in respect of any Collateral arising from the exercise of
the remedies set forth in the Mortgage, first, to the payment to the
Beneficiaries of all amounts owing to the Beneficiaries under the applicable
Operative Documents; provided that if the amount to be applied pursuant to this
clause "first" is less than the sum of such amounts owing to the Beneficiaries,
then the amount to be applied shall be applied in accordance with the
instructions

                                       6

<PAGE>

of the Required Beneficiaries; second, the excess, if any, to be held by the
Security Trustee pursuant to the Mortgage until the Lien of the Mortgage shall
have been terminated; and third, the excess, if any, to the Obligor.

      SECTION 11. Miscellaneous. (a) Survival. Except as otherwise expressly
provided herein, the parties' obligations under this Security Trustee Agreement
shall terminate upon the release of the Lien of the Mortgage.

      (b) Third Party Beneficiary. The Obligor shall be an express third party
beneficiary to this Agreement to the extent the provisions or the Agreement by
their terms confer upon the Obligor any right under this Agreement.

      (c) Notices. All notices, consents, directions, approvals, instructions,
requests and other communications given to any party hereto shall be in writing
to such party at the address set forth in Schedule 2 hereto or, in any such
case, at such other address as such party shall designate by notice to each of
the other parties hereto and may be personally delivered (including delivery by
private courier services) or by telecopy (with a copy of such notice sent by
private courier service for overnight delivery or by registered or certified
mail), to the party entitled thereto, and shall be deemed to be duly given or
made when delivered by hand unless such day is not a Business Day, in which case
such delivery shall be deemed to be made as of the next succeeding Business Day
or in the case of telecopy (with a copy of such notice sent by private courier
service for overnight delivery or by registered or certified mail), when sent,
so long as it was received during normal business hours of the receiving party
on a Business Day and otherwise such delivery shall be deemed to be made as of
the next succeeding Business Day.

      (d) Severability. If any provision hereof or the application thereof to
any Person or circumstance shall be invalid, illegal or unenforceable, the
remaining provisions or the application of such provision to Persons or
circumstances other than those as to which it is invalid or enforceable, shall
continue to be valid and enforceable.

      (e) Amendments, Etc. No amendment or waiver of any provision of this
Security Trustee Agreement shall in any event be effective unless the same shall
be in writing and signed by the Required Beneficiaries and the Security Trustee
and, in the case of any amendment or waiver of Section 10, acknowledged by the
Obligor, and then such waiver or consent shall be effective only in the specific
instance and for the specific purpose for which given.

      (f) Headings. The headings of Sections and subsections of this Security
Trustee Agreement are for convenience only and shall not affect the meaning of
this Security Trustee Agreement.

      (g) Benefit. The parties hereto and their permitted successors and
assigns, but no others, shall be bound hereby and entitled to the benefit
hereof.

      (h) Counterparts. The parties may sign this Security Trustee Agreement in
any number of counterparts and on separate counterparts, each of which shall be
an original but all of which together shall constitute one and the same
instrument.

                                       7

<PAGE>

      (i) Governing Law and Jurisdiction; Waiver of Trial by Jury.

            (i) THIS AGREEMENT HAS BEEN DELIVERED IN THE STATE OF NEW YORK AND
SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF
NEW YORK, INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY AND PERFORMANCE, AND
THE OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE
DETERMINED IN ACCORDANCE WITH SUCH LAWS.

            (ii) Each of the parties hereto, to the extent it may do so under
Applicable Law, for purposes hereof and of all other Operative Documents hereby
(a) irrevocably submits itself to the non-exclusive jurisdiction of the courts
of the State of New York sitting in the City of New York and to the
non-exclusive jurisdiction of the United States District Court for the Southern
District of New York, for the purposes of any suit, action or other proceeding
arising out of this Agreement, the subject matter hereof or any of the
transactions contemplated hereby brought by any party or parties hereto, or
their successors or permitted assigns and (b) waives, and agrees not to assert,
by way of motion, as a defense, or otherwise, in any such suit, action or
proceeding, that the suit, action or proceeding is brought in an inconvenient
forum, that the venue of the suit, action or proceeding is improper or that this
Agreement or the subject matter hereof or any of the transactions contemplated
hereby may not be enforced in or by such courts.

            (iii) TO THE EXTENT PERMITTED BY APPLICABLE LAW, EACH OF THE PARTIES
HERETO IRREVOCABLY WAIVES ALL RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING
OR COUNTERCLAIM TO WHICH THEY ARE PARTIES INVOLVING, DIRECTLY OR INDIRECTLY ANY
MATTER (WHETHER BASED ON CONTRACT, TORT OR OTHERWISE) IN ANY WAY ARISING OUT OF,
RELATED TO, OR CONNECTED WITH THIS AGREEMENT OR ANY RESPECT OF THE TRANSACTIONS
CONTEMPLATED HEREBY OR THE ACTIONS OF THE PARTIES HERETO IN THE NEGOTIATION,
ADMINISTRATION, PERFORMANCE OR ENFORCEMENT THEREOF.

      (j)  Documents. Each of the parties hereto does hereby covenant and agree
to perform and be governed and restricted by the Operative Documents to which it
is a party and, subject to the terms and conditions thereof, to take or cause to
be taken, all actions and to do, or cause to be done, all things necessary,
proper or advisable in connection therewith.

                                       8

<PAGE>

      IN WITNESS WHEREOF, the parties hereto have caused this Security Trustee
Agreement to be duly executed by their respective officers thereunto duly
authorized as of the day and year first above written.

                          SECURITY TRUSTEE:

                          WELLS FARGO BANK NORTHWEST,
                          NATIONAL ASSOCIATION,
                          not in its individual capacity, except as expressly
                          stated herein, but solely as Security Trustee

                          By  /s/ Michael D. Hoggan
                             _______________________________
                             Name: Michael D. Hoggan
                             Title: Vice President

<PAGE>

                          BENEFICIARIES:

                          GENERAL ELECTRIC CAPITAL CORPORATION,
                                as Beneficiary

                          By: /s/ Norman Liu
                             _________________________________
                             Name: Norman Liu
                             Title: Vice President

                          CASTLE HARBOUR LEASING INC., as Beneficiary

                          By: /s/ Norman Liu
                             _______________________________

                              Name: Norman Liu
                              Title: Vice President

                          POLARIS HOLDING COMPANY, as Beneficiary

                          By: /s/ Norman Liu
                             _______________________________

                              Name: Norman Liu
                              Title: Vice President

                          AIRCRAFT SERVICES CORPORATION, as Beneficiary

                          By: /s/ Norman Liu
                              _______________________________

                              Name: Norman Liu
                              Title: Vice President

<PAGE>

                          CASTLE HARBOUR-I LIMITED-LIABILITY
                          COMPANY, as Beneficiary

                          By: /s/ Edward Sun
                              -------------------------------
                              Name: Edward Sun
                              Title: General Manager

                          HELLER FINANCIAL LEASING, INC., as Beneficiary

                          By: /s/ Norman Liu
                              -------------------------------
                              Name: Norman Liu
                              Title: Vice President

                          HELLER EMX, INC., as Beneficiary

                          By: /s/ Norman Liu
                              -------------------------------
                              Name: Norman Liu
                              Title: Vice President

                          AFS INVESTMENTS XI, INC., as Beneficiary

                          By: /s/ Norman Liu
                              -------------------------------
                              Name: Norman Liu
                              Title: Vice President

                          POLARIS LEASING INTERNATIONAL, INC., as Beneficiary

                          By: /s/ Norman Liu
                              -------------------------------
                              Name: Norman Liu
                              Title: Vice President

<PAGE>

                          AFS INVESTMENTS XV LLC, as Beneficiary, by its member,
                          AFS Investments XV, Inc.

                          By: /s/ Norman Liu
                              -------------------------------
                              Name: Norman Liu
                              Title: Vice President

                          AFS INVESTMENTS XLI LLC, as Beneficiary, by its
                          member, AFS Investments XLI, Inc.

                          By: /s/ Norman Liu
                              -------------------------------
                              Name: Norman Liu
                              Title: Vice President

                          AFS INVESTMENTS XLII LLC, as Beneficiary, by its
                          member, AFS Investments XLII, Inc.

                          By: /s/ Norman Liu
                              -------------------------------
                              Name: Norman Liu
                              Title: Vice President

                          AVIATION FINANCIAL SERVICES INC., as Beneficiary

                          By: /s/ Norman Liu
                              -------------------------------
                              Name: Norman Liu
                              Title: Vice President

                          PK AIRFINANCE S.A.R.L., as Beneficiary

                          By: /s/ Michael Kriedberg
                              -------------------------------
                              Name: Michael Kriedberg
                              Title: Director

<PAGE>

                                                                      SCHEDULE 1

                                  BENEFICIARIES

1.    General Electric Capital Corporation

2.    Castle Harbour Leasing Inc.

3.    Polaris Holding Company

4.    Aircraft Services Corporation

5.    Castle Harbour-I Limited-Liability Company

6.    Heller Financial Leasing, Inc.

7.    Heller EMX, Inc.

8.    AFS Investments XI, Inc.

9.    Polaris Leasing International, Inc.

10.   AFS Investments XV LLC

11.   AFS Investments XLI LLC

12.   AFS Investments XLII LLC

13.   Aviation Financial Services Inc.

14.   PK AirFinance S.A.R.L.

<PAGE>

                                                                      SCHEDULE 2

                                 NOTICE DETAILS

If to the Security Trustee, to:

            Wells Fargo Bank Northwest, National Association
            MAC: U1228-120
            299 South Main Street
            12th Floor
            Salt Lake City, Utah 84111
            Attention:  Corporate Trust Services

            Telephone:        (801) 246-5630
            Fax No.           (801) 246-5053
            E-mail:           michael.hoggan@wellsfargo.com

If to any of the Beneficairies, to:

            General Electric Capital Corporation
            c/o GE Capital Aviation Services, Inc.
            201 High Ridge Road
            Stamford, CT  06927

            Attention:        Customer Services
            Telecopy:         (203) 357 3201
            Email:            Nanotices@gecas.com

<PAGE>

                                                                         Annex A

[Date]

TO:

Wells Fargo Bank Northwest, National Association

                         Re: America West Airlines, Inc.

We refer to the Security Trustee Agreement [Spare Parts] dated as of September
3, 2004 ("Security Trustee Agreement") between Wells Fargo Bank Northwest,
National Association as Security Trustee and the persons named therein as
Beneficiaries. Capitalized terms herein not defined shall have the same meanings
as set forth in the Security Trustee Agreement.

The undersigned hereby (a) certifies to you that the undersigned is a
Beneficiary and (b) requests you, pursuant to Section 10(a) of the Security
Trustee Agreement, to send a notice to each Beneficiary substantially in the
form of Annex B to the Security Trustee Agreement.

                          [NAME OF BENEFICIARY]

                          By_______________________________
                          Name:
                          Title:

<PAGE>

                                                                         Annex B

[Date]

TO:
[Name of Beneficiary] ("Beneficiary")
[Address of Beneficiary]

                         Re: America West Airlines, Inc.

In our capacity as Security Trustee under the Security Trustee Agreement [Spare
Parts] dated as of September 3, 2004 ("Security Trustee Agreement") between
Wells Fargo Bank Northwest, National Association, as Security Trustee, and the
persons named therein as Beneficiaries (capitalized terms herein not defined
shall have the same meanings as set forth in the Security Trustee Agreement) we
hereby request that you certify to the undersigned in writing, within 30 days of
receipt of this notice, the full amount owing to the Beneficiary under the
Payment & Indemnity Agreement.

Such certification referred to above shall attach a copy of this letter and be
sent to:

      WELLS FARGO BANK NORTHWEST,
      NATIONAL ASSOCIATION ("Security Trustee")

      [________________]
      Attention: [____________]
      (Telecopy No. [_________])

                              WELLS FARGO BANK NORTHWEST,
                              NATIONAL ASSOCIATION,
                              not in its individual capacity, except as
                              expressly stated herein, but solely as
                              Security Trustee

                              By_______________________________
                              Name:
                              Title: