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                [MORRIS, JAMES, HITCHENS & WILLIAMS LETTERHEAD]

                                                                     Exhibit 5.1

December 16, 1998

America West Airlines, Inc.
51 W. Third Street
Tempe, Arizona 85281

RE: AMERICA WEST AIRLINES PASS THROUGH CERTIFICATES, SERIES 1998-1

Ladies and Gentlemen:

         You have asked us to provide you with an opinion in connection with the
filing of a registration statement on Form S-4 (the "Registration Statement")
with the Securities and Exchange Commission pursuant to the Securities Act of
1933, as amended (the "Securities Act"), in respect of the registration under
the Securities Act of the Pass Through Certificates, Series 1998-1A (the "New
Class A Certificates"), the Pass Through Certificates, Series 1998-1B (the "New
Class B Certificates") and the Pass Through Certificates, Series 1998-1C (the
"New Class C Certificates" and, together with the New Class A Certificates and
the New Class B Certificates, the "New Certificates"), to be offered in exchange
for all outstanding Pass Through Certificates, Series 1998-1A, Series 1998-1B
and Series 1998-1C (collectively, the "Old Certificates"). Each of the New Class
A Certificates, the New Class B Certificates and the New Class C Certificates
represents or will represent a fractional undivided interest in on of the
following corresponding pass through trusts: the America West Airlines Pass
Through Trust, Series 1998-1A-O, the America West Airlines Pass Through Trust,
Series 1998-1A-S, the America West Airlines Pass Through Trust, Series
1998-1B-O, the America West Airlines Pass Through Trust, Series 1998-1B-S, the
America West Airlines Pass Through Trust, Series 1998-1C-O and the America West
Airlines Pass Through Trust, Series 1998-1C-S (collectively, the "Trusts"). The
Trusts were formed pursuant to three separate pass through trust agreements,
dated as of October 6, 1998 (the "Pass Through Trust Agreements"), between
America West Airlines, Inc. ("America West" or the "Company") and Wilmington
Trust Company, as pass through trustee under each Trust (the "Trustee"). In its
individual capacity, Wilmington Trust Company is herein referred to as
"Wilmington Trust").

         In connection with this opinion letter, we have examined the
Registration Statement, including the Prospectus that forms a part of the
Registration Statement. We have also examined executed counterparts, forms or
copies otherwise identified to our satisfaction of the following documents: the
Pass Through Trust Agreements, the Exchange and Registration Rights Agreement,
dated October 6, 1998 (the "Registration Rights Agreement"), and the forms of
Old Certificates and New Certificates, each filed as an exhibit to the
Registration Statement (collectively, the "Documents"). We have also examined
and relied on originals or copies of such other documents, such corporate
records, certificates and other statements of governmental officials and
corporate officers and other representatives of the corporations or entities
referred to herein and such other instruments as we have deemed necessary or
appropriate for the


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America West Airlines, Inc.
December 16, 1998
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purposes of this opinion. Moreover, as to certain facts material to the opinions
expressed herein, we have relied upon the representations and warranties
contained in the Documents.

         Based on the foregoing and upon an examination of such questions of law
as we have considered necessary or appropriate, and subject to the assumptions,
exceptions and qualifications set forth herein, we advise you that, in our
opinion:

         1. When issued in exchange for the Old Certificates pursuant to the
Registration Rights Agreement and authenticated pursuant to the Pass Through
Trust Agreements, the New Certificates will be duly authorized, legal, valid and
binding obligations of the Trusts, enforceable against the Trusts in accordance
with their terms and the terms of the Pass Through Trust Agreements and will be
entitled to the benefits of the Pass Through Trust Agreements.

         The foregoing opinion is subject to the following assumptions,
exceptions and qualifications:

         A. The foregoing opinion is limited to the laws of the State of
Delaware and the federal laws of the United States of America governing the
banking and trust powers of Wilmington Trust. In addition, we express no opinion
with respect to (i) federal securities laws, including without limitation the
Securities Act, the Securities Exchange Act of 1934, as amended, the Investment
Company Act of 1940, as amended, and the Trust Indenture Act of 1939, as
amended, (ii) Part A of Subtitle VII of Title 49 of the United States Code, as
amended, (iii) the Federal Communications Act of 1934, as amended, (iv) state
securities or blue sky laws, or (v) laws, rules and regulations applicable for
the particular nature of the equipment acquired by the Company. Insofar as the
foregoing opinions relate to the validity and enforceability of the Documents
which are expressed to be governed by the laws of any state other than the State
of Delaware, we have assumed that each such document is legal, valid, binding
and enforceable in accordance with its terms under such laws (as to which we
express no opinion).

         B. The foregoing opinion regarding enforceability of any document are
subject to (i) applicable bankruptcy, insolvency, moratorium, reorganization,
fraudulent conveyance, receivership and similar laws relating to or affecting
the rights and remedies of creditors generally, and (ii) general principles of
equity (regardless of whether such enforceability is considered and applied in a
proceeding in equity or at law).

         C. We have assumed the due authorization, execution and delivery by
each of the parties thereto (other than Wilmington Trust in its individual
capacity, or as Trustee, as the case may be) of the Documents to which each is a
party and that each of such parties has the full power, authority and legal
right to execute, delivery and perform each such document.

         D. We have assumed that all signatures (other than those of Wilmington
Trust in its individual capacity, or as Trustee, as the case may be) on
documents and instruments examined 


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America West Airlines, Inc.
December 16, 1998
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by us are genuine, that all documents and instruments submitted to us as
originals are authentic, and that all documents and instruments submitted to us
as copies or specimens conform with the originals, which facts we have not
independently verified.

         E. We have not participated in the preparation of the Registration
Statement or the Prospectus that forms a part of the Registration Statement and
assume no responsibility for their contents.

         This opinion may be relied upon by you in connection with the matters
set forth herein. Without our prior written consent, this opinion may not be
furnished or quoted to, or relied upon by, any other person or entity for any
purpose. Notwithstanding the foregoing, we hereby consent to the filing of this
opinion as an exhibit to the Registration Statement and to the reference to this
Firm under the headings "Legal Matters" in the Prospectus included in the
Registration Statement. In giving such consent, we do not thereby admit that we
are "experts" within the meaning of the Securities Act or the rules and
regulations of the Securities and Exchange Commission issued thereunder with
respect to any part of the Registration Statement, including this exhibit.


                                       Very truly yours,


                                       /s/ Morris, James, Hitchens & Williams