<PAGE>
 
                                                                   EXHIBIT 10.33



                            FRONTIER AIRLINES, INC.


                         REGISTRATION RIGHTS AGREEMENT



                           Dated as of May 26, 1998
<PAGE>
 
                               TABLE OF CONTENTS
                               -----------------


     THIS TABLE OF CONTENTS IS NOT PART OF THE AGREEMENT TO WHICH IT IS ATTACHED
BUT IS INSERTED FOR CONVENIENCE ONLY.

                                                                            Page
                                                                             No.
                                                                            ----

1.  Requested Registrations................................................  1
    -----------------------
        (a)    Registration Requests.......................................  1
               ---------------------
        (b)    Limitations on Requested Registrations......................  2
               --------------------------------------
        (c)    Registration Statement Form.................................  2
               ---------------------------
        (d)    Registration Expenses.......................................  2
               ---------------------
        (e)    Priority in Cutback Registrations...........................  2
               ---------------------------------

2.  Piggyback Registrations................................................  2
    -----------------------
        (a)    Right to Include Registrable Securities.....................  2
               ---------------------------------------
        (b)    Registration Expenses.......................................  3
               ---------------------
        (c)    Priority in Cutback Registrations...........................  3
               ---------------------------------

3.  Registration Procedures................................................  4
    -----------------------

4.  Underwritten Offerings.................................................  8
    ----------------------
        (a)    Underwritten Requested Offerings............................  8
               --------------------------------
        (b)    Underwritten Piggyback Offerings............................  8
               --------------------------------

5.  Indemnification........................................................  9
    ---------------
        (a)    Indemnification by the Company..............................  9
               ------------------------------
        (b)    Indemnification by the Sellers..............................  10
               ------------------------------
        (c)    Notices of Claims, etc......................................  10
               -----------------------
        (d)    Contribution................................................  11
               ------------
        (e)    Other Indemnification.......................................  12
               ---------------------
        (f)    Indemnification Payments....................................  12
               ------------------------

6.  Covenants Relating to Rule 144.........................................  12
    ------------------------------

7.  Other Registration Rights..............................................  12
    -------------------------
        (a)    No Existing Agreements......................................  12
               ----------------------
        (b)    Future Agreements...........................................  12
               -----------------

8.  Definitions............................................................  13
    -----------

9.   Miscellaneous.........................................................  16
     -------------
        (a)    Notices.....................................................  16
               -------
        (b)    Entire Agreement............................................  17
               ----------------
        (c)    Amendment...................................................  17
               ---------
        (d)    Waiver......................................................  17
               ------
        (e)    Consents and Waivers by Holders of Registrable Securities...  17
               ----------------------------------------------------------
        (f)    No Third Party Beneficiary..................................  18
               --------------------------
<PAGE>
 
        (g)    Successors and Assigns......................................  18
               ----------------------
        (h)    Headings....................................................  18
               --------
        (i)    Invalid Provisions..........................................  18
               ------------------
        (j)    Remedies....................................................  18
               --------
        (k)    Governing Law...............................................  18
               -------------
        (l)    Counterparts................................................  19
               ------------




                                     -ii-
<PAGE>
 
                            FRONTIER AIRLINES, INC.

                         REGISTRATION RIGHTS AGREEMENT
                         -----------------------------



          This REGISTRATION RIGHTS AGREEMENT dated as of May 26, 1998 is made
and entered into by and between The Seabury Group, LLC, a limited liability
company ("Seabury"), and Frontier Airlines, Inc., a Colorado corporation (the
"Company").  Capitalized terms not otherwise defined herein have the meanings
--------                                                                     
set forth in Section 8.
             --------- 

          WHEREAS, Seabury or an affiliate of Seabury has provided financial
advisory services to the Company under a Financial Advisory Agreement dated May
26, 1998 (the "Advisory Agreement").

          WHEREAS, Seabury and the Company have entered into a Warrant Agreement
dated as of May 26, 1998 (the "Warrant Agreement").

          WHEREAS, the Warrant Agreement and the Advisory Agreement provide that
the Company enter into a registration rights agreement with Seabury pursuant to
which the Company will grant to Seabury certain registration rights with respect
to the Common Stock underlying the Warrants (the "Warrant Stock");
                                                  -------------   

          NOW, THEREFORE, in consideration of the mutual covenants and
agreements set forth in this Agreement, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto agree as follows:

          1.  Requested Registrations.   (a)  Registration Requests.  At any
              -----------------------         ---------------------         
time after the first anniversary of this agreement, upon the written request of
Seabury (either on its own behalf or on behalf of any holder of Registrable
Securities) requesting that the Company effect the registration under the
Securities Act of all or part of Seabury's (or any such holder's) Registrable
Securities and specifying the number of Registrable Securities to be registered
and the intended method of disposition thereof, the Company will promptly, and
in no event more than 10 Business Days after receipt of such request, give
written notice (a "Notice of Requested Registration") of such request to all
                   --------------------------------                         
other holders of Registrable Securities, and thereupon will use its best efforts
to effect the registration under the Securities Act of

          (i)   the Registrable Securities which the Company has been so
     requested to register by Seabury, and

          (ii)  all other Registrable Securities the holders of which have made
     written requests to the Company for registration thereof within 15 days
     after the giving of the Notice of Requested Registration (which requests
     shall specify the intended method of disposition thereof),

all to the extent requisite to permit the disposition (in accordance with the
intended methods thereof) of the Registrable Securities so to be registered in
accordance with Section 3.  If requested 
                ---------                                                     
<PAGE>
 
by Seabury, the method of disposition of all Registrable Securities included in
such registration shall be an underwritten offering effected in accordance with
Section 4(a). Neither the Company nor any of its securityholders shall have the
------------              
right to include any of the Company's securities (other than Registrable
Securities) in a registration statement to be filed as part of a Requested
Registration.

          (b) Limitations on Requested Registrations.  Notwithstanding anything
              --------------------------------------                           
herein to the contrary, the Company shall not be required to honor a request for
a Requested Registration if, in the case of a Long-Form Registration, the
Company has previously effected one Effective Long-Form Registration; provided
                                                                      --------
that there shall be no limit on the number of registrations effected as Short-
Form Registrations, subject to the other provisions of this Section 1(b).
                                                            ------------ 

          (c)  Registration Statement Form.  Subject to Section 1(b), requested
               ---------------------------                                     
Registrations shall be on such appropriate registration form promulgated by the
Commission as shall be selected by the Company, and shall be reasonably
acceptable to Seabury, and shall permit the disposition of such Registrable
Securities in accordance with the intended method or methods specified in their
request for such registration, but the Company may not effect a Long-Form
Registration without Seabury's consent.  Notwithstanding the foregoing, if in
the case of an underwritten offering on Form S-3 the Managing Underwriter
notifies the Company that in its judgment the inclusion of more detailed
information of the type required in Form S-1 is of material importance to such
offering, the Company shall include in the Registration Statement such
information.

          (d)  Registration Expenses.  The Company will pay all Registration
               ---------------------                                        
Expenses incurred in connection with any Requested Registration.

          (e)  Priority in Cutback Registrations.  If a Requested Registration
               ---------------------------------                              
becomes a Cutback Registration, the Company will include in any such
registration to the extent of the number which the Managing Underwriter advises
the Company can be sold in such offering Registrable Securities requested to be
included in such registration by the Initiating Holders, pro rata on the basis
                                                         --- ----             
of the number of Registrable Securities requested to be included by such
holders.

          2.  Piggyback Registrations.   (a)  Right to Include Registrable
              -----------------------         ----------------------------
Securities. Notwithstanding any limitation contained in Section 1, if the
----------                                              ---------        
Company at any time proposes after the first anniversary of the date hereof to
effect a Piggyback Registration, it will each such time give written notice (a
"Notice of Piggyback Registration"), at least 30 days prior to the anticipated
---------------------------------                                             
filing date, to all holders of Registrable Securities of its intention to do so
and of such holders' rights under this Section 2, which Notice of Piggyback
                                       ---------                           
Registration shall include a description of the intended method of disposition
of such securities.  Upon the written request of any such holder made within 20
days after receipt of a Notice of Piggyback Registration (which request shall
specify the Registrable Securities intended to be disposed of by such holder) ,
the Company will, subject to the other provisions of this Agreement, include in
the registration statement relating to such Piggyback Registration all
Registrable Securities which the Company has been so requested to register, all
to the extent requisite to permit the disposition of such Registrable Securities
in 

                                      -2-
<PAGE>
 
accordance with the intended method of disposition set forth in the Notice of
Piggyback Registration.  Notwithstanding the foregoing, if, at any time after
giving a Notice of Piggyback Registration and prior to the effective date of the
registration statement filed in connection with such registration, the Company
shall determine for any reason not to register or to delay registration of such
securities, the Company may, at its election, give written notice of such
determination to each holder of Registrable Securities and, thereupon, (i) in
the case of a determination not to register, shall be relieved of its obligation
to register any Registrable Securities in connection with such registration (but
not from its obligation to pay the Registration Expenses in connection
therewith) without prejudice, however, to the rights of any Requesting Holder
entitled to do so to request that such registration be effected as a Requested
Registration under Section 1, and (ii) in the case of a determination to delay
                   ---------                                                  
registering, shall be permitted to delay registering any Registrable Securities
for the same period as the delay in registering such other securities.  No
registration effected under this Section 2 shall relieve the Company of its
                                 ---------                                 
obligations to effect a Requested Registration under Section 1 with respect to
                                                     ---------                
Registrable Securities that are not registered and sold thereunder.

          (b)  Registration Expenses.  The Company will pay all Registration
               ---------------------                                        
Expenses incurred in connection with each Piggyback Registration.

          (c)  Priority in Cutback Registrations.  If a Piggyback Registration
               ---------------------------------                              
becomes a Cutback Registration, the Company will include in such registration to
the extent of the amount of the securities which the Managing Underwriter
advises the Company can be sold in such offering:

          (i)  if such Piggyback Registration as initially proposed by the
     Company was solely a primary registration of its securities, (x) first, the
                                                                      -----     
     securities proposed by the Company to be sold for its own account, and (y)
     second, (A) if no other holders of securities of the Company have requested
     ------                                                                     
     registration of their securities in such registration, any Registrable
     Securities requested to be included in such registration by Requesting
     Holders, pro rata on the basis of the number of Registrable Securities
              --- ----                                                     
     requested to be included by such holders or (B) if other holders of
     securities of the Company have requested registration of their securities
     in such registration, such securities of such holders and any Registrable
     Securities requested to be included in such registration by Requesting
     Holders, on a pari passu basis; and

         (ii)  if such Piggyback Registration as initially proposed by the
     Company was in whole or in part requested by holders of securities of the
     Company, other than holders of Registrable Securities in their capacities
     as such, pursuant to demand registration rights, such securities held by
     the holders initiating such registration and any Registrable Securities
     requested to be included in such registration by Requesting Holders, on a
     pari passu basis;

and any securities so excluded shall be withdrawn from and shall not be included
in such Piggyback Registration.

                                      -3-
<PAGE>
 
          3.  Registration Procedures.  If and whenever the Company is required
              -----------------------                                          
to effect the registration of any Registrable Securities under the Securities
Act pursuant to Section 1 or Section 2, the Company will use its best efforts to
                ---------    ---------                                          
effect the registration and sale of such Registrable Securities in accordance
with the intended method of disposition thereof.  Without limiting the
foregoing, the Company in each such case will, as expeditiously as possible, use
its best efforts:

          (a)  to prepare and file with the Commission (in the case of a
     Requested Registration, not later than 20 days after the filing by the
     Company with the Commission of its next required report on Form 10-K or
     Form 10-Q, as the case may be, under the Exchange Act, or as soon
     thereafter as possible) the requisite registration statement to effect such
     registration and to cause such registration statement to become effective,
     provided that the Company may defer filing a registration statement for up
     to 90 days after the filing would otherwise be required to be made pursuant
     to this section if and so long as, in the reasonable judgment of the
     Company's Board of Directors, the filing of such registration statement
     within the period otherwise required by this Section 3(a) would compel the
                                                  ------------                 
     Company to disclose material nonpublic information the disclosure of which
     would be materially detrimental to the Company or would materially
     interfere with any material financing, acquisition, corporate
     reorganization, or merger involving the Company.

          (b)  as far in advance as practical before filing such registration
     statement or any amendment thereto, to furnish to the Requesting Holders
     copies of reasonably complete drafts of all such documents proposed to be
     filed (including exhibits), and any such holder shall have the opportunity
     to object to any information pertaining solely to such holder that is
     contained therein and the Company will make the corrections reasonably
     requested by such holder with respect to such information prior to filing
     any such registration statement or amendment;

          (c)  to prepare and file with the Commission such amendments and
     supplements to such registration statement and any prospectus used in
     connection therewith as may be necessary to maintain the effectiveness of
     such registration statement and to comply with the provisions of the
     Securities Act with respect to the disposition of all Registrable
     Securities covered by such registration statement, in accordance with the
     intended methods of disposition thereof, until such time as all of such
     securities have been disposed of in accordance with the intended methods of
     disposition by the seller or sellers thereof set forth in such registration
     statement;

          (d) to promptly notify each Requesting Holder and the underwriter or
     underwriters, if any:

              (i)  when such registration statement or any prospectus used in
          connection therewith, or any amendment or supplement thereto, has been
          filed and, with respect to such registration statement or any post-
          effective amendment thereto, when the same has become effective;

                                      -4-
<PAGE>
 
              (ii)  of any written comments from the Commission with respect to
          any filing referred to in clause (i) and of any written request by the
          Commission for amendments or supplements to such registration
          statement or prospectus;

             (iii)  of the notification to the Company by the Commission of its
          initiation of any proceeding with respect to the issuance by the
          Commission of, or of the issuance by the Commission of, any stop order
          suspending the effectiveness of such registration statement; and

             (iv)   of the receipt by the Company of any notification with
          respect to the suspension of the qualification of any Registrable
          Securities for sale under the applicable securities or blue sky laws
          of any jurisdiction;

          (e)  to furnish to each seller of Registrable Securities covered by
     such registration statement such number of conformed copies of such
     registration statement and of each amendment and supplement thereto (in
     each case including all exhibits and documents incorporated by reference),
     such number of copies of the prospectus contained in such registration
     statement (including each preliminary prospectus and any summary
     prospectus) and any other prospectus filed under Rule 424 promulgated under
     the Securities Act relating to such holder's Registrable Securities, and
     such other documents, as such seller may reasonably request to facilitate
     the disposition of its Registrable Securities;

          (f)  to register or qualify all Registrable Securities covered by such
     registration statement under such other securities or blue sky laws of such
     jurisdictions as each holder thereof shall reasonably request, to keep such
     registration or qualification in effect for so long as such registration
     statement remains in effect, and take any other action which may be
     reasonably necessary or advisable to enable such holder to consummate the
     disposition in such jurisdictions of the Registrable Securities owned by
     such holder, except that the Company shall not for any such purpose be
     required (i) to qualify generally to do business as a foreign corporation
     in any jurisdiction wherein it would not but for the requirements of this
     paragraph (f) be obligated to be so qualified, (ii) to subject itself to
     -------------                                                           
     taxation in any such jurisdiction or (iii) to consent to general service of
     process in any jurisdiction;

          (g)  to cause all Registrable Securities covered by such registration
     statement to be registered with or approved by such other governmental
     agencies or authorities as may be necessary to enable each holder thereof
     to consummate the disposition of such Registrable Securities;

          (h)  to furnish to each Requesting Holder a signed counterpart,
     addressed to such holder (and the underwriters, if any), of

               (i)  an opinion of counsel for the Company, dated the effective
          date of such registration statement (or, if such registration includes
          an underwritten Public 

                                      -5-
<PAGE>
 
          Offering, dated the date of any closing under the underwriting
          agreement), reasonably satisfactory in form and substance to such
          holder, and

              (ii)  a "comfort" letter, dated the effective date of such
          registration statement (and, if such registration includes an
          underwritten Public Offering, dated the date of any closing under the
          underwriting agreement), signed by the independent public accountants
          who have certified the Company's financial statements included in such
          registration statement,

     in each case covering substantially the same matters with respect to such
     registration statement (and the prospectus included therein) and, in the
     case of the accountants' letter, with respect to events subsequent to the
     date of such financial statements, as are customarily covered in opinions
     of issuer's counsel and in accountants' letters delivered to the
     underwriters in underwritten Public Offerings of securities and, in the
     case of the accountants' letter, such other financial matters, as such
     holder (or the underwriters, if any) may reasonably request;

          (i)  to notify each holder of Registrable Securities covered by such
     registration statement, at any time when a prospectus relating thereto is
     required to be delivered under the Securities Act, of the happening of any
     event as a result of which any prospectus included in such registration
     statement, as then in effect, includes an untrue statement of a material
     fact or omits to state any material fact required to be stated therein or
     necessary to make the statements therein, in the light of the circumstances
     under which they were made, not misleading, and at the request of any such
     holder promptly prepare and furnish to such holder a reasonable number of
     copies of a supplement to or an amendment of such prospectus as may be
     necessary so that, as thereafter delivered to the purchasers of such
     securities, such prospectus shall not include an untrue statement of a
     material fact or omit to state a material fact required to be stated
     therein or necessary to make the statements therein, in the light of the
     circumstances under which they were made, not misleading;

          (j)  to otherwise use its best efforts to comply with all applicable
     rules and regulations of the Commission, and make available to its
     securityholders, as soon as reasonably practicable, an earnings statement
     covering the period of at least twelve months, but not more than eighteen
     months, beginning with the first full calendar month after the effective
     date of such registration statement, which earnings statement shall satisfy
     the provisions of Section 11(a) of the Securities Act and Rule 158
     promulgated thereunder;

          (k)  to make available for inspection by any Requesting Holder, any
     underwriter participating in any disposition pursuant to such registration
     statement and any attorney, accountant or other agent retained by any such
     seller or underwriter (collectively, the "Inspectors"), all financial and
                                               ----------                     
     other records, pertinent corporate documents and properties of the Company
     (collectively, the "Records") as shall be reasonably necessary to enable
                         -------                                             
     them to exercise their due diligence responsibility, and cause the
     Company's officers, directors and employees to supply all information
     reasonably requested by any such 

                                      -6-
<PAGE>
 
     Inspector in connection with such registration statement, and permit the
     Inspectors to participate in the preparation of such registration statement
     and any prospectus contained therein and any amendment or supplement
     thereto. Records which the Company determines, in good faith, to be
     confidential and which it notifies the Inspectors are confidential shall
     not be disclosed by the Inspectors unless (i) the disclosure of such
     Records is necessary to avoid or correct a misstatement or omission in the
     registration statement, (ii) the release of such Records is ordered
     pursuant to a subpoena or other order from a court of competent
     jurisdiction or (iii) the information in such Records has been made
     generally available to the public. The seller of Registrable Securities
     agrees by acquisition of such Registrable Securities that it will, upon
     learning that disclosure of such Records is sought in a court of competent
     jurisdiction, give notice to the Company and allow the Company, at the
     Company's expense, to undertake appropriate action to prevent disclosure of
     the Records deemed confidential;

          (l)  to provide a transfer agent and registrar for all Registrable
     Securities covered by such registration statement not later than the
     effective date of such registration statement; and

          (m)  to cause all Registrable Securities covered by such registration
     statement to be listed, upon official notice of issuance, on any securities
     exchange on which any of the securities of the same class as the
     Registrable Securities are then listed.

          The Company may require each holder of Registrable Securities as to
which any registration is being effected to, and each such holder, as a
condition to including Registrable Securities in such registration, shall,
furnish the Company with such information and affidavits regarding such holder
and the distribution of such securities as the Company may from time to time
reasonably request in writing in connection with such registration.

          Each holder of Registrable Securities agrees by acquisition of such
Registrable Securities that upon receipt of any notice from the Company of the
happening of any event of the kind described in paragraph (h), such holder will
                                                -------------                  
forthwith discontinue such holder's disposition of Registrable Securities
pursuant to the registration statement relating to such Registrable Securities
until such holder's receipt of the copies of the supplemented or amended
prospectus contemplated by paragraph (h) and, if so directed by the Company,
                           -------------                                    
will deliver to the Company (at the Company's expense) all copies, other than
permanent file copies, then in such holder's possession of the prospectus
relating to such Registrable Securities current at the time of receipt of such
notice.

          4.  Underwritten Offerings.
              ---------------------- 

          (a)  Underwritten Requested Offerings.  In the case of any
               --------------------------------                     
underwritten Public Offering being effected pursuant to a Requested
Registration, the Managing Underwriter and any other underwriter or underwriters
with respect to such offering shall be selected, after consultation with the
Company, by the holders of a majority of the Registrable Securities to be
included in such underwritten offering with the consent of the Company, which
consent shall not be unreasonably 

                                      -7-
<PAGE>
 
withheld. The Company shall enter into an underwriting agreement in customary
form with such underwriter or underwriters, which shall include, among other
provisions, indemnities to the effect and to the extent provided in Section 5.
                                                                    ---------
The holders of Registrable Securities to be distributed by such underwriters
shall be parties to such underwriting agreement and may, at their option,
require that any or all of the representations and warranties by, and the other
agreements on the part of, the Company to and for the benefit of such
underwriters also be made to and for their benefit and that any or all of the
conditions precedent to the obligations of such underwriters under such
underwriting agreement also be conditions precedent to their obligations. No
holder of Registrable Securities shall be required to make any representations
or warranties to or agreements with the Company or the underwriters other than
representations, warranties or agreements regarding such holder and its
ownership of the securities being registered on its behalf and such holder's
intended method of distribution and any other representation required by law. No
Requesting Holder may participate in such underwritten offering unless such
holder agrees to sell its Registrable Securities on the basis provided in such
underwriting agreement and completes and executes all questionnaires, powers of
attorney, indemnities and other documents reasonably required under the terms of
such underwriting agreement. If any Requesting Holder disapproves of the terms
of an underwriting, such holder may elect to withdraw therefrom and from such
registration by notice to the Company and the Managing Underwriter, and each of
the remaining Requesting Holders shall be entitled to increase the number of
Registrable Securities being registered to the extent of the Registrable
Securities so withdrawn in the proportion which the number of Registrable
Securities being registered by such remaining Requesting Holder bears to the
total number of Registrable Securities being registered by all such remaining
Requesting Holders.

          (b)  Underwritten Piggyback Offerings.  If the Company at any time
               --------------------------------                             
proposes to register any of its securities in a Piggyback Registration and such
securities are to be distributed by or through one or more underwriters, the
Company will, subject to the provisions of Section 2(c), use its best efforts to
                                           ------------                         
arrange for such underwriters to include the Registrable Securities to be
offered and sold by Requesting Holders among the securities to be distributed by
such underwriters.  The holders of Registrable Securities to be distributed by
such underwriters shall be parties to the underwriting agreement between the
Company and such underwriter or underwriters and may, at their option, require
that any or all of the representations and warranties by, and the other
agreements on the part of, the Company to and for the benefit of such
underwriters also be made to and for their benefit and that any or all of the
conditions precedent to the obligations of such underwriters under such
underwriting agreement also be conditions precedent to their obligations.  No
holder of Registrable Securities shall be required to make any representations
or warranties to or agreements with the Company or the underwriters other than
representations, warranties or agreements regarding such holder and its
ownership of the securities being registered on its behalf and any other
representation required by law.  No Requesting Holder may participate in such
underwritten offering unless such holder agrees to sell its Registrable
Securities on the basis provided in such underwriting agreement and completes
and executes all questionnaires, powers of attorney, indemnities and other
documents reasonably required under the terms of such underwriting agreement.
If any Requesting Holder disapproves of the terms of an underwriting, such
holder may elect to withdraw therefrom and from such registration by notice to
the Company and the Managing Underwriter, and each of the remaining Requesting
Holders shall be entitled to 

                                      -8-
<PAGE>
 
increase the number of Registrable Securities being registered to the extent of
the Registrable Securities so withdrawn in the proportion which the number of
Registrable Securities being registered by such remaining Requesting Holder
bears to the total number of Registrable Securities being registered by all such
remaining Requesting Holders.

          5.  Indemnification.   (a)  Indemnification by the Company.  The
              ---------------         ------------------------------      
Company shall, to the full extent permitted by law, indemnify and hold harmless
each seller of Registrable Securities included in any registration statement
filed in connection with a Requested Registration or a Piggyback Registration,
its directors and officers, and each other Person, if any, who controls any such
seller within the meaning of the Securities Act, against any Losses, claims,
damages, expenses or liabilities, joint or several (together, "Losses"), to
                                                               ------      
which such seller or any such director or officer or controlling Person may
become subject under the Securities Act or otherwise, insofar as such Losses (or
actions or proceedings, whether commenced or threatened, in respect thereof)
arise out of or are based upon any untrue statement or alleged untrue statement
of any material fact contained in any such registration statement, any
preliminary prospectus, final prospectus or summary prospectus contained
therein, or any amendment or supplement thereto, or any omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein (in the case of a prospectus, in the
light of the circumstances under which they were made) not misleading, and the
Company will reimburse such seller and each such director, officer and
controlling Person for any legal or any other expenses reasonably incurred by
them in connection with investigating or defending any such Loss (or action or
proceeding in respect thereof); provided that the Company shall not be liable in
                                --------                                        
any such case to the extent that any such Loss (or action or proceeding in
respect thereof) arises out of or is based upon an untrue statement or alleged
untrue statement or omission or alleged omission made in any such registration
statement, preliminary prospectus, final prospectus, summary prospectus,
amendment or supplement in reliance upon and in conformity with written
information furnished to the Company through an instrument duly executed by such
seller specifically stating that it is for use in the preparation thereof.  Such
indemnity shall remain in full force and effect regardless of any investigation
made by or on behalf of such seller or any such director, officer or controlling
Person, and shall survive the transfer of such securities by such seller.  The
Company shall also indemnify each other Person who participates (including as an
underwriter) in the offering or sale of Registrable Securities, their officers
and directors and each other Person, if any, who controls any such participating
Person within the meaning of the Securities Act to the same extent as provided
above with respect to sellers of Registrable Securities.

          (b)  Indemnification by the Sellers.  Each holder of Registrable
               ------------------------------                             
Securities which are included or are to be included in any registration
statement filed in connection with a Requested Registration or a Piggyback
Registration, as a condition to including Registrable Securities in such
registration statement, shall, to the full extent permitted by law, indemnify
and hold harmless the Company, its directors and officers, and each other
Person, if any, who controls the Company within the meaning of the Securities
Act, against any Losses to which the Company or any such director or officer or
controlling Person may become subject under the Securities Act or otherwise,
insofar as such Losses (or actions or proceedings, whether commenced or
threatened, in respect thereof) arise out of or are based upon any untrue
statement or alleged untrue statement of any 

                                      -9-
<PAGE>
 
material fact contained in any such registration statement, any preliminary
prospectus, final prospectus or summary prospectus contained therein, or any
amendment or supplement thereto, or any omission or alleged omission to state
therein a material fact required to be stated therein or necessary to make the
statements therein (in the case of a prospectus, in the light of the
circumstances under which they were made) not misleading, if such untrue
statement or alleged untrue statement or omission or alleged omission was made
in reliance upon and in conformity with written information furnished to the
Company through an instrument duly executed by such seller specifically stating
that it is for use in the preparation of such registration statement,
preliminary prospectus, final prospectus, summary prospectus, amendment or
supplement; provided, however, that the obligation to provide indemnification
            --------  -------                        
pursuant to this Section 5(b) shall be several, and not joint and several, among
                 ------------                          
such Indemnifying Parties on the basis of the number of Registrable Securities
included in such registration statement and the aggregate amount which may be
recovered from any holder of Registrable Securities pursuant to the
indemnification provided for in this Section 5(b) in connection with any
                                     ------------                       
registration and sale of Registrable Securities shall be limited to the total
proceeds received by such holder from the sale of such Registrable Securities.
Such indemnity shall remain in full force and effect regardless of any
investigation made by or on behalf of the Company or any such director, officer
or controlling Person and shall survive the transfer of such securities by such
seller. Such holders shall also indemnify each other Person who participates
(including as an underwriter) in the offering or sale of Registrable Securities,
their officers and directors and each other Person, if any, who controls any
such participating Person within the meaning of the Securities Act to the same
extent as provided above with respect to the Company.

          (c)  Notices of Claims, etc.  Promptly after receipt by an Indemnified
               -----------------------                                          
Party of notice of the commencement of any action or proceeding involving a
claim referred to in the preceding paragraph (a) or (b) of this Section 5, such
                                   --------------------         ---------      
Indemnified Party will, if a claim in respect thereof is to be made against an
Indemnifying Party pursuant to such paragraphs, give written notice to the
latter of the commencement of such action, provided that the failure of any
                                           --------                        
Indemnified Party to give notice as provided herein shall not relieve the
Indemnifying Party of its obligations under the preceding paragraphs of this
                                                                            
Section 5, except to the extent that the Indemnifying Party is actually
---------                                                              
prejudiced by such failure to give notice.  In case any such action is brought
against an Indemnified Party, the Indemnifying Party shall be entitled to
participate in and, unless, in the judgment of any Indemnified Party, a conflict
of interest between such Indemnified Party and any Indemnifying Party exists
with respect to such claim, to assume the defense thereof, jointly with any
other Indemnifying Party similarly notified to the extent that it may wish, with
counsel reasonably satisfactory to such Indemnified Party, and after notice from
the Indemnifying Party to such Indemnified Party of its election so to assume
the defense thereof, the Indemnifying Party shall not be liable to such
Indemnified Party for any legal or other expenses subsequently incurred by the
latter in connection with the defense thereof other than reasonable costs of
investigation; provided that the Indemnified Party may participate in such
               --------                                                   
defense at the Indemnified Party's expense; and provided further that the
                                                -------- -------         
Indemnified Party or Indemnified Parties shall have the right to employ one
counsel to represent it or them if, in the reasonable judgment of the
Indemnified Party or Indemnified Parties, it is advisable for it or them to be
represented by separate counsel by reason of having legal defenses which are
different from or in addition to those available to the Indemnifying Party, and
in that 

                                      -10-
<PAGE>
 
event the reasonable fees and expenses of such one counsel shall be paid by the
Indemnifying Party. If the Indemnifying Party is not entitled to, or elects not
to, assume the defense of a claim, it will not be obligated to pay the fees and
expenses of more than one counsel for the Indemnified Parties with respect to
such claim, unless in the reasonable judgment of any Indemnified Party a
conflict of interest may exist between such Indemnified Party and any other
Indemnified Parties with respect to such claim, in which event the Indemnifying
Party shall be obligated to pay the fees and expenses of such additional counsel
for the Indemnified Parties or counsels. No Indemnifying Party shall consent to
entry of any judgment or enter into any settlement without the consent of the
Indemnified Party which does not include as an unconditional term thereof the
giving by the claimant or plaintiff to such Indemnified Party of a release from
all liability in respect to such claim or litigation. No Indemnifying Party
shall be subject to any liability for any settlement made without its consent,
which consent shall not be unreasonably withheld.

          (d)  Contribution.  If the indemnity and reimbursement obligation
               ------------                                                
provided for in any paragraph of this Section 5 is unavailable or insufficient
                                      ---------                               
to hold harmless an Indemnified Party in respect of any Losses (or actions or
proceedings in respect thereof) referred to therein, then the Indemnifying Party
shall contribute to the amount paid or payable by the Indemnified Party as a
result of such Losses (or actions or proceedings in respect thereof) in such
proportion as is appropriate to reflect the relative fault of the Indemnifying
Party on the one hand and the Indemnified Party on the other hand in connection
with statements or omissions which resulted in such Losses, as well as any other
relevant equitable considerations.  The relative fault shall be determined by
reference to, among other things, whether the untrue or alleged untrue statement
of a material fact or the omission or alleged omission to state a material fact
relates to information supplied by the Indemnifying Party or the Indemnified
Party and the parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such untrue statement or omission.  The
parties hereto agree that it would not be just and equitable if contributions
pursuant to this paragraph were to be determined by pro rata allocation or by
                                                    --- ----                 
any other method of allocation which does not take account of the equitable
considerations referred to in the first sentence of this paragraph.  The amount
paid by an Indemnified Party as a result of the Losses referred to in the first
sentence of this paragraph shall be deemed to include any legal and other
expenses reasonably incurred by such Indemnified Party in connection with
investigating or defending any Loss which is the subject of this paragraph.

          No Indemnified Party guilty of fraudulent misrepresentation (within
the meaning of Section 11(f) of the Securities Act) shall be entitled to
contribution from the Indemnifying Party if the Indemnifying Party was not
guilty of such fraudulent misrepresentation.

          (e)  Other Indemnification.  Indemnification similar to that specified
               ---------------------                                            
in the preceding paragraphs of this Section 5 (with appropriate modifications)
                                    ---------                                 
shall be given by the Company and each seller of Registrable Securities with
respect to any required registration or other qualification of securities under
any federal or state law or regulation of any governmental authority other than
the Securities Act.  The provisions of this Section 5 shall be in addition to
                                            ---------                        
any other rights to indemnification or contribution which an Indemnified Party
may have pursuant to law, equity, contract or otherwise.

                                      -11-
<PAGE>
 
          (f)  Indemnification Payments.  The indemnification required by this
               ------------------------                                       
Section 5 shall be made by periodic payments of the amount thereof during the
---------                                                                    
course of the investigation or defense, as and when bills are received or Losses
are incurred.

          6.  Covenants Relating to Rule 144.  The Company will file reports in
              ------------------------------                                   
compliance with the Exchange Act, will comply with all rules and regulations of
the Commission applicable in connection with the use of Rule 144 and take such
other actions and furnish such holder with such other information as such holder
may request in order to avail itself of such rule or any other rule or
regulation of the Commission allowing such holder to sell any Registrable
Securities without registration.  If at any time the Company is not required to
file reports in compliance with either Section 13 or Section 15(d) of the
Exchange Act, the Company at its expense will, forthwith upon the written
request of the holder of any Registrable Securities, make available adequate
current public information with respect to the Company within the meaning of
paragraph (c)(2) of Rule 144.

          7.  Other Registration Rights.
              ------------------------- 

          (a) No Existing Agreements.  The Company represents and warrants to
              ----------------------                                         
Seabury that there is not in effect on the date hereof any agreement by the
Company (other than this Agreement and as set forth in Schedule 3.06 to the
                                                       -------------       
Warrant Agreement) pursuant to which any holders of securities of the Company
have a right to cause the Company to register or qualify such securities under
the Securities Act.

          (b) Future Agreements.  Reference is made to the Amended and Restated
              -----------------                                                
Registration Rights Agreement dated as of February 27, 1998 between the Company
and Wexford Management, LLC (the "Wexford Agreement"), a copy of which has been
provided to Seabury. Seabury and the Requesting Holders agree that (i) they may
not participate in any Requested Registration except as provided in Section 1 of
                                                                    ---------   
the Wexford Agreement and (ii) they may not participate in any Piggyback
Registration except as provided in Section 2 of the Wexford Agreement.
                                   ---------                          

          8.  Definitions.
              ----------- 

          (a) Except as otherwise specifically indicated, the following terms
will have the following meanings for all purposes of this Agreement:

          "Agreement" means this Registration Rights Agreement, as the same
           ---------                                                       
shall be amended from time to time.

          "Business Day" means a day other than Saturday, Sunday or any other
           ------------                                                      
day on which banks located in the State of New York are authorized or obligated
to close.

          "Commission" means the United States Securities and Exchange
           ----------                                                 
Commission, or any successor governmental agency or authority.

                                      -12-
<PAGE>
 
          "Common Stock" means shares of Common Stock, no par value per share,
           ------------                                                       
of the Company, as constituted on the date hereof, and any stock into which such
Common Stock shall have been changed or any stock resulting from any
reclassification of such Common Stock.

          "Company" has the meaning ascribed to it in the preamble.
           -------                                                 

          "Cutback Registration" means any Requested Registration or Piggyback
           --------------------                                               
Registration to be effected as an underwritten Public Offering in which the
Managing Underwriter with respect thereto advises the Company and the Requesting
Holders in writing that, in its opinion, the number of securities requested to
be included in such registration (including securities of the Company which are
not Registrable Securities) exceed the number which can be sold in such offering
without a material reduction in the selling price anticipated to be received for
the securities to be sold in such Public Offering.

          "Effective Long-Form Registration" means a Long-Form Registration that
           --------------------------------                                     
results in an Effective Registration.

          "Effective Registration" means a Requested Registration which (a) has
           ----------------------                                              
been declared or ordered effective in accordance with the rules of the
Commission and (b) has been kept effective for the period of time contemplated
by Section 3(b).
   ------------ 

          "Effective Short-Form Registration" means a Short-Form Registration
           ---------------------------------                                 
that results in an Effective Registration.

          "Exchange Act" means the Securities Exchange Act of 1934, as amended,
           ------------                                                        
and the rules and regulations promulgated thereunder.

          "Form S-1" means Form S-1 promulgated by the Commission under the
           --------                                                        
Securities Act, or any successor or similar long-form registration statement.

          "Form S-2" means Form S-2 promulgated by the Commission under the
           --------                                                        
Securities Act, or any successor or similar short-form registration statement.

          "Form S-3" means Form S-3 promulgated by the Commission under the
           --------                                                        
Securities Act, or any successor or similar short-form registration statement.

          "Indemnified Party" means a party entitled to indemnity in accordance
           -----------------                                                   
with Section 5.
     --------- 

          "Indemnifying Party" means a party obligated to provide indemnity in
           ------------------                                                 
accordance with Section 5.
                --------- 

                                      -13-
<PAGE>
 
          "Initiating Holders" means Seabury and any holder of Registrable
           ------------------                                             
Securities with respect to which Seabury has made a written request pursuant to
Section 1 for the registration of Registrable Securities.
---------                                                

          "Inspectors" has the meaning ascribed to it in Section 3(i).
           ----------                                    ------------ 

          "Letter Agreement" has the meaning ascribed to it in the preamble.
           ----------------                                                 

          "Long-Form Registration" means a Requested Registration effected by
           ----------------------                                            
the filing of a registration statement on Form S-1 with the Commission.

          "Losses" has the meaning ascribed to it in Section 5(a).
           ------                                    ------------ 

          "Managing Underwriter" means, with respect to any Public Offering, the
           --------------------                                                 
underwriter or underwriters managing such Public Offering.

          "NASD" means the National Association of Securities Dealers.
           ----                                                       

          "Notice of Piggyback Registration" has the meaning ascribed to it in
           --------------------------------                                   
Section 2(a).
------------ 

          "Notice of Requested Registration" has the meaning ascribed to it in
           --------------------------------                                   
Section 1(a).
------------ 

          "Person" means any natural person, corporation, general partnership,
           ------                                                             
limited partnership, limited liability company, proprietorship, other business
organization, trust, union or association.

          "Piggyback Registration" means any registration of securities of the
           ----------------------                                             
Company of the same class as any of the Registrable Securities under the
Securities Act (other than a registration in respect of a dividend reinvestment
or similar plan for shareholders of the Company or on Form S-4 or Form S-8
promulgated by the Commission, or any successor or similar forms thereto),
whether for sale for the account of the Company or for the account of any holder
of securities of the Company (other than Registrable Securities.

          "Public Offering" means any offering of Common Stock to the public,
           ---------------                                                   
either on behalf of the Company or any of its securityholders, pursuant to an
effective registration statement under the Securities Act (other than a
registration in respect of a dividend reinvestment or similar plan for
shareholders of the Company or on Form S-4 or Form S-8 promulgated by the
Commission, or any successor or similar forms thereto).

          "Records" has the meaning ascribed to it in Section 3(i).
           -------                                    ------------ 

          "Registrable Securities" means (i) shares of Warrant Stock, and (ii)
           ----------------------                                             
any additional shares of Common Stock or other securities issued or distributed
by way of a dividend, stock split or other distribution in respect of the any of
the securities referred to in clause (i), or acquired by 

                                      -14-
<PAGE>
 
way of any rights offering or similar offering made in respect of such
securities. As to any particular Registrable Securities, once issued such
securities shall cease to be Registrable Securities when (i) a registration
statement with respect to the sale of such securities shall have become
effective under the Securities Act and such securities shall have been disposed
of in accordance with such registration statement, (ii) they shall have been
sold to the public pursuant to Rule 144, or (iii) they shall have ceased to be
outstanding.

          "Registration Expenses" means all expenses incident to the Company's
           ---------------------                                              
performance of or compliance with its obligations under this Agreement to effect
the registration of Registrable Securities in a Requested Registration or a
Piggyback Registration, including, without limitation, all registration, filing,
securities exchange listing and NASD fees, all registration, filing,
qualification and other fees and expenses of complying with securities or blue
sky laws, all word processing, duplicating and printing expenses, messenger and
delivery expenses, the fees and disbursements of counsel for the Company and of
its independent public accountants, including the expenses of any special audits
or "cold comfort" letters required by or incident to such performance and
compliance, the reasonable fees and disbursements of a single counsel, premiums
and other costs of policies of insurance purchased by the Company against
liabilities arising out of the Public Offering of the Registrable Securities
being registered and any fees and disbursements of underwriters customarily paid
by issuers or sellers of securities if the offering is an underwritten offering
initiated by the Company, but excluding underwriting discounts and commissions
and transfer taxes, if any, in respect of Registrable Securities and fees and
disbursements of underwriters if the offering is an underwritten offering
initiated by Seabury or the Requesting Holders, which shall be payable by each
holder thereof.

          "Requesting Holders" means, with respect to any Requested Registration
           ------------------                                                   
or Piggyback Registration, the holders of Registrable Securities requesting to
have Registrable Securities included in such registration in accordance with
this Agreement.

          "Requested Registration" means any registration of Registrable
           ----------------------                                       
Securities under the Securities Act effected in accordance with Section 1.
                                                                --------- 

          "Rule 144" means Rule 144 promulgated by the Commission under the
           --------                                                        
Securities Act, and any successor provision thereto.

          "Securities Act" means the Securities Act of 1933, as amended, and the
           --------------                                                       
rules and regulations promulgated thereunder.

          "Short-Form Registration" means a Requested Registration effected by
           -----------------------                                            
the filing of a registration statement on Form S-2 or Form S-3 with the
Commission.

          "Warrant Stock" has the meaning ascribed to it in the preamble.
           -------------                                                 

          (b)  Unless the context of this Agreement otherwise requires, (i)
words of any gender include each other gender; (ii) words using the singular or
plural number also include the 

                                      -15-
<PAGE>
 
plural or singular number, respectively; (iii) the terms "hereof," "herein,"
"hereby" and derivative or similar words refer to this entire Agreement; and
(iv) the term "Section" refers to the specified Section of this Agreement.
Whenever this Agreement refers to a number of days, such number shall refer to
calendar days unless Business Days are specified.

          9.  Miscellaneous.
              ------------- 

          (a)  Notices.  All notices, requests and other communications
               -------                                                 
hereunder must be in writing and will be deemed to have been duly given only if
delivered personally or by facsimile transmission or mailed (first class postage
prepaid) to the parties at the following addresses or facsimile numbers:

               If to Investor, to:

               The Seabury Group, LLC
               135 West 50th Street, Suite 1820
               New York, New York  10020

               Attn: John Luth
               Facsimile No.:  (212) 541-6334

               If to the Company, to:

                    Frontier Airlines, Inc.
                    12015 East 46th Avenue
                    Denver, Colorado  80239

                    Attn:  Arthur T. Voss, General Counsel
                    Facsimile No.:  (303) 371-9669

With respect to any other holder of Registrable Securities, such notices,
requests and other communications shall be sent to the addresses set forth in
the transfer records regularly maintained by the Company.  All such notices,
requests and other communications will (i) if delivered personally to the
address as provided in this Section, be deemed given upon delivery, (ii) if
delivered by facsimile transmission to the facsimile number as provided in this
Section, be deemed given upon receipt, and (iii) if delivered by mail in the
manner described above to the address as provided in this Section, be deemed
given upon receipt (in each case regardless of whether such notice, request or
other communication is received by any other Person to whom a copy of such
notice is to be delivered pursuant to this Section).  Any party from time to
time may change its address, facsimile number or other information for the
purpose of notices to that party by giving notice specifying such change to the
other parties hereto.

                                      -16-
<PAGE>
 
          (b) Entire Agreement.  This Agreement supersedes all prior discussions
              ----------------                                                  
and agreements between the parties with respect to the subject matter hereof,
and contains the sole and entire agreement between the parties hereto with
respect to the subject matter hereof.

          (c)  Amendment.  This Agreement may be amended, supplemented or
               ---------                                                 
modified only by a written instrument (which may be executed in any number of
counterparts) duly executed by or on behalf of each of the Company and Seabury.

          (d) Waiver.  Subject to paragraph (e) of this Section, any term or
              ------              -------------                             
condition of this Agreement may be waived at any time by the party that is
entitled to the benefit thereof, but no such waiver shall be effective unless
set forth in a written instrument duly executed by or on behalf of the party
waiving such term or condition.  No waiver by any party of any term or condition
of this Agreement, in any one or more instances, shall be deemed to be or
construed as a waiver of the same term or condition of this Agreement on any
future occasion.

          (e) Consents and Waivers by Holders of Registrable Securities.  Any
              ---------------------------------------------------------      
consent of the holders of Registrable Securities pursuant to this Agreement, and
any waiver by such holders of any provision of this Agreement, shall be in
writing (which may be executed in any number of counterparts) and may be given
or taken by Seabury, and any such consent or waiver so given or taken will be
binding on all the holders of Registrable Securities.

          (f) No Third Party Beneficiary.  The terms and provisions of this
              --------------------------                                   
Agreement are intended solely for the benefit of each party hereto, their
respective successors or permitted assigns and any other holder of Registrable
Securities, and it is not the intention of the parties to confer third-party
beneficiary rights upon any other Person other than any Person entitled to
indemnity under Section 5.
                --------- 

          (g) Successors and Assigns.  This Agreement is binding upon, inures to
              ----------------------                                            
the benefit of and is enforceable by the parties hereto and their respective
successors and assigns.

          (h) Headings.  The headings used in this Agreement have been inserted
              --------                                                         
for convenience of reference only and do not define or limit the provisions
hereof.

          (i)  Invalid Provisions.  If any provision of this Agreement is held
               ------------------                                             
to be illegal, invalid or unenforceable under any present or future law, and if
the rights or obligations of any party hereto under this Agreement will not be
materially and adversely affected thereby, (i) such provision will be fully
severable, (ii) this Agreement will be construed and enforced as if such
illegal, invalid or unenforceable provision had never comprised a part hereof
and (iii) the remaining provisions of this Agreement will remain in full force
and effect and will not be affected by the illegal, invalid or unenforceable
provision or by its severance herefrom.

          (j) Remedies.  Except as otherwise expressly provided for herein, no
              --------                                                        
remedy conferred by any of the specific provisions of this Agreement is intended
to be exclusive of any other remedy, and each and every remedy shall be
cumulative and shall be in addition to every other 

                                      -17-
<PAGE>
 
remedy given hereunder or now or hereafter existing at law or in equity or by
statute or otherwise. The election of any one or more remedies by any party
hereto shall not constitute a waiver by any such party of the right to pursue
any other available remedies.

          Damages in the event of breach of this Agreement by a party hereto or
any other holder of Registrable Securities would be difficult, if not
impossible, to ascertain, and it is therefore agreed that each such Person, in
addition to and without limiting any other remedy or right it may have, will
have the right to an injunction or other equitable relief in any court of
competent jurisdiction, enjoining any such breach, and enforcing specifically
the terms and provisions hereof and the Company and each holder of Registrable
Securities, by its acquisition of such Registrable Securities, hereby waives any
and all defenses it may have on the ground of lack of jurisdiction or competence
of the court to grant such an injunction or other equitable relief.  The
existence of this right will not preclude any such Person from pursuing any
other rights and remedies at law or in equity which such Person may have.

          (k) Governing Law.  This Agreement shall be governed by and construed
              -------------                                                    
in accordance with the laws of the State of New York applicable to a contract
executed and performed in such State, without giving effect to the conflicts of
laws principles thereof.

          (l)  Counterparts.  This Agreement may be executed in any number of
               ------------                                                  
counterparts, each of which will be deemed an original, but all of which
together will constitute one and the same instrument.

          IN WITNESS WHEREOF, this Agreement has been duly executed and
delivered by the duly authorized officer of each party hereto as of the date
first above written.


                              THE SEABURY GROUP, LLC


                              By: __________________________
                                  Name:
                                  Title:


                              FRONTIER AIRLINES, INC.


                              By: __________________________
                                  Name:
                                  Title: