Document:

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                                                                    Exhibit 10.1

                                  GENCORP INC.

                                    as Issuer

                           THE GUARANTORS PARTY HERETO

                                  as Guarantors

                                       and

                              THE BANK OF NEW YORK

                                   as Trustee

                  ---------------------------------------------

                          First Supplemental Indenture

                          Dated as of October 29, 2004

                    To Indenture Dated as of August 11, 2003

                    9-1/2% Senior Subordinated Notes due 2013

                  ---------------------------------------------

<PAGE>

      FIRST SUPPLEMENTAL INDENTURE, dated as of October 29, 2004 (the "First
Supplemental Indenture"), between GENCORP INC., an Ohio corporation (the
"Issuer"), the guarantors party hereto (the "Guarantors") and THE BANK OF NEW
YORK, as trustee (the "Trustee").

                                    RECITALS

      WHEREAS, the Issuer, the guarantors party thereto and the Trustee have
heretofore executed and delivered an Indenture, dated as of August 11, 2003 (the
"Indenture"), pursuant to which the Issuer issued $150,000,000 principal amount
of its 9-1/2% Senior Subordinated Notes due 2013 (the "Notes"), all of which
remain issued and outstanding under the Indenture;

      WHEREAS, this First Supplemental Indenture is being executed pursuant to a
Consent Solicitation Statement of the Issuer, dated October 20, 2004 (the
"Statement"), and the related Letter of Consent;

      WHEREAS, Section 9.2 of the Indenture provides that the Issuer, the
guarantors and the Trustee may enter into indentures supplemental to the
Indenture for the purpose of changing or modifying in any manner the rights of
the Holders of Notes with the consent of the Holders of at least a majority in
aggregate principal amount of the Notes then outstanding, subject to certain
exceptions specified in Section 9.2 of the Indenture;

      WHEREAS, the parties hereto are entering into this First Supplemental
Indenture to amend Sections 1.1 and 4.10 of the Indenture (the "Amendment");

      WHEREAS, the execution and delivery of this First Supplemental Indenture
and the adoption of the Amendment by the Issuer, the Guarantors and the Trustee
has been authorized by the consent of the Holders of at least a majority in
aggregate principal amount of the Notes outstanding as of the date hereof; and

      WHEREAS, the execution and delivery of this First Supplemental Indenture
by the Issuer have been authorized by resolutions of the Board of Directors of
the Issuer, the execution and delivery of this First Supplemental Indenture by
the Guarantors have been authorized by the board of directors, manager or
members of each Guarantor, and, subject to the conditions set forth in the
Statement, all acts, conditions and requirements necessary to make this First
Supplemental Indenture a valid and binding agreement in accordance with its
terms and for the purposes herein set forth have been done and taken, and the
execution and delivery of this First Supplemental Indenture have been in all
respects duly authorized.

      NOW, THEREFORE, in consideration of the above premises, each party hereto
agrees, for the benefit of the other party and for the equal and ratable benefit
of the Holders of the Notes, as follows:

Section 1.   Definitions.

      For all purposes of this First Supplemental Indenture, except as otherwise
expressly provided or unless the context otherwise requires, the terms used
herein shall have the respective meanings assigned to them in the Indenture.

<PAGE>

Section 2.   Amendment of the Indenture.

            (a)   The definition of "Refinancing Indebtedness" in Section 1.1
of the Indenture is hereby amended and restated to read in its entirety as
follows:

      "Refinancing Indebtedness' means Indebtedness incurred in connection with
any Refinancing by the Company of its 5-3/4% Convertible Subordinated Notes due
2007 (the "5-3/4% Convertible Notes") or any Refinancing by the Company or any
Restricted Subsidiary of the Company of any Indebtedness (including Disqualified
Capital Stock) incurred in accordance with Section 4.9 (provided that
Refinancing Indebtedness shall not include Indebtedness described in clauses
(i), (iii), (iv), (v), (vi), (vii), (viii), (ix), (x), (xi), (xii), (xiii),
(xv), (xvi), (xvii), (xviii), (xix), (xx) (other than the 5-3/4% Convertible
Notes) and (xxii) of the definition of Permitted Indebtedness), in each case
that does not (1) result in an increase in the aggregate principal amount or
liquidation preference of Indebtedness (or if such Indebtedness was issued with
an original issue discount, the accreted value thereof as determined in
accordance with GAAP) of such Person (except to the extent that any such
increase is otherwise permitted by the Indenture); provided, that such
Refinancing Indebtedness may increase such principal amount by the amount of
reasonable expenses incurred by the Company or such Restricted Subsidiary, as
the case may be, in connection with such Refinancing, and the amount of any
premium necessary to accomplish such Refinancing, or (2) create Indebtedness
with (A) a Weighted Average Life to Maturity that is less than the Weighted
Average Life to Maturity of the Indebtedness being Refinanced or (B) a final
maturity or redemption date earlier than the final maturity or redemption date
of the Indebtedness being Refinanced; provided, however, that (x) if such
Indebtedness being Refinanced is Indebtedness of the Company, then such
Refinancing Indebtedness shall be Indebtedness solely of the Company and (y) if
such Indebtedness being Refinanced is subordinate or junior to the Notes or the
guarantees, then such Refinancing Indebtedness shall be subordinate to the Notes
or the guarantees, as the case may be, at least to the same extent and in the
same manner as the Indebtedness being Refinanced."

            (b)   Clause (4) of the penultimate paragraph of Section 4.10 of the
Indenture is hereby amended and restated to read in its entirety as follows:

      "(4) if no Default or Event of Default shall have occurred and be
continuing, the acquisition (by redemption, repurchase or otherwise) of any
Indebtedness of the Company, any Restricted Subsidiary, any Real Estate Venture
or any Permitted Joint Venture that is subordinate or junior in right of payment
to the Notes either (i) solely in exchange for shares of Qualified Capital Stock
of the Company or Refinancing Indebtedness, or (ii) through the application of
the net proceeds of a sale for cash (other than to a Subsidiary of the Company)
of (A) shares of Qualified Capital Stock of the Company or (B) Refinancing
Indebtedness, in each case contemplated in this clause (ii) within ten Business
Days of such sale;"

Section 3. (c) Operation of First Supplemental Indenture.

      This First Supplemental Indenture shall take effect on the date that the
Trustee receives a certification of results from Global Bondholder Services
Corporation, the Issuer's tabulation agent, indicating receipt of the consent of
the Holders of at least a majority in aggregate principal amount of the Notes
and shall amend the provisions of the Indenture with respect to the Notes.

<PAGE>

Section 4.  Concerning the Trustee.

      The Trustee accepts the trusts of the Indenture, as supplemented by this
First Supplemental Indenture, and agrees to perform the same, but only upon the
terms and conditions set forth in the Indenture, as supplemented by this First
Supplemental Indenture, to which the parties hereto and the Holders from time to
time of the Notes agree and, except as expressly set forth in the Indenture, as
supplemented by this First Supplemental Indenture, shall incur no liability or
responsibility in respect thereof. Without limiting the generality of the
foregoing, the Trustee assumes no responsibility for the correctness of the
recitals herein contained, which shall be taken as the statements of the Issuer.
The Trustee makes no representation and shall have no responsibility as to the
validity or sufficiency of this First Supplemental Indenture.

Section 5.  Miscellaneous.

            (a)   Except as hereby expressly amended, the Indenture is in all
      respects ratified and confirmed and all the terms, provisions and
      conditions thereof shall be and remain in full force and effect.

            (b)   All agreements of the Issuer in this First Supplemental
      Indenture shall bind the Issuer's successors. All agreements of the
      Trustee in this First Supplemental Indenture shall bind its successors.

            (c)   THIS FIRST SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY THE
      LAWS OF THE STATE OF NEW YORK AS APPLIED TO CONTRACTS MADE AND PERFORMED
      WITHIN THE STATE OF NEW YORK WITHOUT REGARD TO PRINCIPLES OF CONFLICTS OF
      LAW.

            (d)   If and to the extent that any provision of this First
      Supplemental Indenture limits, qualifies or conflicts with another
      provision that is required to be included in this First Supplemental
      Indenture or in the Indenture by the Trust Indenture Act, the required
      provision shall control.

            (e)   The titles and headings of the sections of this First
      Supplemental Indenture have been inserted for convenience of reference
      only, and are not to be considered a part hereof and shall in no way
      modify or restrict any of the terms or provisions hereof.

            (f)   This First Supplemental Indenture may be executed in any
      number of counterparts, each of which shall be deemed an original, but all
      of which together shall represent one and the same agreement.

            (g)   In case any provision of this First Supplemental Indenture
      shall be determined to be invalid, illegal or unenforceable, the validity,
      legality and enforceability of the remaining provisions hereof or of the
      Indenture shall not in any way be affected or impaired thereby.

<PAGE>

      IN WITNESS WHEREOF, the parties hereto have caused this First Supplemental
Indenture to be duly executed, and their respective corporate seals to be
hereunto affixed, as of the date first written above.

                                         ISSUER

                                         GENCORP INC.

                                         By: /s/ Mark A. Whitney
                                             -----------------------------
                                             Name:  Mark A. Whitney
                                             Title: Vice President, Law

                                         GUARANTORS

                                         AEROJET-GENERAL CORPORATION

                                         By: /s/ Mark A. Whitney
                                             -----------------------------
                                             Name:  Mark A. Whitney
                                             Title: Secretary

                                         AEROJET ORDNANCE TENNESEE, INC.

                                         By: /s/ Nabara Kazimi
                                             -----------------------------
                                             Name:  Nabara Kazimi
                                             Title:  Assistant Treasurer

                                         GENCORP PROPERTY INC.

                                         By: /s/ Mark A. Whitney
                                             -----------------------------
                                             Name:  Mark A. Whitney
                                             Title: Vice President and Assistant
                                                    Secretary

                                         GDX LLC

                                         By: /s/ Mark A. Whitney
                                             -----------------------------
                                             Name:  Mark A. Whitney
                                             Title: Vice President and Secretary

<PAGE>

                                         AEROJET FINE CHEMICALS LLC

                                         By: /s/ Margaret Hastings
                                             -----------------------------
                                             Name:   Margaret Hastings
                                             Title:  Vice President, Law

                                         AEROJET INVESTMENTS LTD.

                                         By: /s/ Roger W. Overland
                                             -----------------------------
                                             Name:  Roger W. Overland
                                             Title: Assistant Secretary

                                         RKO GENERAL, INC.

                                         By: /s/ Mark A. Whitney
                                             -----------------------------
                                             Name:  Mark A. Whitney
                                             Title: Vice President and Secretary

                                         TRUSTEE

                                         THE BANK OF NEW YORK

                                         By: /s/ Sandee Parks
                                             -----------------------------
                                             Name:  Sandee Parks
                                             Title: Vice President<PAGE>

                                                                    Exhibit 10.1

                       SECOND AMENDMENT TO LEASE AGREEMENT

      This Second Amendment to Lease Agreement (this "Amendment") is entered
into as of the 26th day of July, 2004, by and between William Brooks Real Estate
Company, an Ohio corporation ("Lessor"), and Rocky Shoes & Boots, Inc., an Ohio
corporation ("Lessee").

                                    RECITALS

      A. Lessor and Lessee entered into that certain Lease Agreement dated as of
May 1, 1998, which was amended in that Amended and Restated Lease Agreement
dated March 1, 2002 (collectively, the "Lease"), whereby Lessee agreed to lease
from Lessor the shoe factory located at 45 East Canal Street, Nelsonville, Ohio
and the parking lot located at 13-78 Myers Street in Nelsonville, Ohio and more
particularly described on Exhibit A (the "Leased Premises");

      B. Lessee is operating the Leased Premises under a Renewal Option, which
commenced March 1, 2004 and expires February 28, 2005;

      C. Lessor and Lessee now desire to amend the Lease to change the Rent, to
amend the terms and conditions of the Option to Purchase the Leased Premises and
to otherwise modify the Lease as herein provided, all on and subject to the
terms and conditions hereof.

      NOW, THEREFORE, for and in consideration of the mutual agreements
contained herein and for other good and valuable consideration, the parties
agree as follows:

1.    Lease: The term "Lease" shall hereinafter be meant to include both the
      Lease and this Amendment.

2.    Section 13.01, Renewal Option, of Article 13, OPTION TO RENEW OR EXTEND,
      is hereby deleted in its entirety and replaced with the following:

            13.01 If the Lessee is not then in default of its obligation to pay
                  rent or of any other obligations hereunder, Lessee shall have
                  the right to renew this Lease for Renewal Terms of one year
                  beginning on March 1, 2004, under the same terms and
                  conditions as this Lease; provided, however, that the monthly
                  base Rent during the Renewal Terms shall be increased to an
                  amount equal to 104% of the base Rent of the immediately
                  preceding Lease year, except that the monthly base rent during
                  the Renewal Option beginning March 31, 2004 and expiring
                  February 28, 2005 shall be Five Thousand Dollars ($5,000.00).
                  Lessee may exercise the options to renew by giving Lessor
                  written notice thereof at least six months prior to the
                  expiration of the Initial Term and each subsequent Renewal
                  Term;

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3.    Article 14, Option to Purchase Leases Premises, is hereby deleted in its
      entirety and replaced with the following:

      Article 14. Purchase and Sale

            14.1  Lessor agrees to sell and convey to Lessee and Lessee agrees
                  to buy and pay for the Leased Premises on or before January
                  31, 2005.

            14.2  Lessor agrees at the time of closing to convey fee simple
                  title to the Leases Premises to Lessee by general warranty
                  deed subject to (a) zoning ordinances affecting the Leased
                  Premises, (b) ad valorem taxes not yet due and payable and (c)
                  such other matters as may be agreed to in writing by the
                  Lessee.

            14.3  The purchase price (the "Purchase Price") of the Leased
                  Premises shall be Five Hundred Five Thousand Dollars and
                  00/100 ($505,000.00), and shall be paid by Lessee's certified
                  check, bank check or wire transfer at the closing of the sale
                  of the Leased Premises.

            14.4  Lessor warrants and represents to Lessee that as of the date
                  hereof and as of the date of closing:

                  a.    Lessor is the owner of good and marketable fee simple
                        title to the Leased Premises, free and clear of all
                        liens, easements, restrictions, options, reservations,
                        mortgages, security titles and interest, covenants,
                        conditions, rights of way, licenses, permits,
                        encumbrances, leases, tenancies, claims of lessees in
                        possession and rights of any kind, except for matters
                        set forth in Exhibit B attached hereto and incorporated
                        herein by reference (the "Permitted Encumbrances").

                  b.    So long as this agreement remains in force, Lessor will
                        not lease, rent or convey all or any portion of the
                        Leased Premises or any interest therein, or enter into
                        any agreement granting to any person or entity any right
                        with respect to the Leased Premises, or any portion
                        thereof, without first obtaining the written consent of
                        Lessee.

                  c.    Lessor is not now a party to any litigation,
                        investigation or other proceeding nor to the knowledge
                        of Lessor is any such litigation, investigation or
                        proceeding threatened, which relates to the Leased
                        Premises, directly or indirectly, or Lessor's right to
                        sell the Leased Premises.

                                       2
<PAGE>

                  d.    Lessor has no knowledge of any pending, threatened or
                        contemplated condemnation proceedings, which will or may
                        affect the Leased Premises in any, respect whatsoever.

                  e.    Lessor has no notice of and is not aware of any
                        violation of any laws, ordinances, orders, restrictive
                        covenants or other requirements affecting the Leased
                        Premises, and there are no violations of record of any
                        of the foregoing.

                  f.    There are no commitments to governmental authorities or
                        agencies or utilities or quasi govern- mental entities,
                        which affect the Lease Premises and no conditions of
                        zoning of the Leased Premises, which have not been
                        completed, fulfilled.

                  g.    There are no taxes, assessments or levies of any type
                        (except ad valorem taxes for year 2004) relating to the
                        Leased Premises which are presently due and payable or
                        which may become a lien or other charge against any part
                        of the Leased Premises.

                  h.    The improvements (if any) are within the boundary lines
                        of the Leased Premises described in Exhibit A and there
                        are no encroachments on the Leased Premises of any
                        adjoining landowner.

                  i     To the best of Lessor's knowledge, the Leased Premises
                        has never been used as a landfill to receive solid
                        waste, whether or not hazardous and has never been used
                        for the disposal, storage or treatment of any waste,
                        trash, garbage, industrial by-product, chemical or
                        hazardous substance of any nature, including without
                        limitation radioactive materials, PCBs, asbestos,
                        pesticides, herbicides, pesticide or herbicide
                        containers, untreated sewage, industrial process sludge
                        or any "hazardous substance" as such term is defined in
                        the following sources as amended from time to time: (i)
                        the Resource and Conservation and Recovery Act of 1976,
                        42 U.S.C. Section 6901 et seq. ("RCRA"); (ii) the
                        Hazardous Material Transportation Act, 49 U.S.C. Section
                        1801, et. seq. ("HMTA"); (iii) the Comprehensive
                        Environmental Response Compensation and Liability Act of
                        1980, 42 U.S.C. Section 9601 et. seq. ("CERCLA"); (iv)
                        applicable laws of the jurisdiction where the Leased
                        Premises is located, and (v) any federal, state or local
                        statutes, regulations, ordinances, or rules or orders

                                       3
<PAGE>

                        issued or promulgated under or pursuant to any of those
                        laws or otherwise by any department, agency or other
                        administrative, regulatory or judicial body. The Leased
                        Premises does not contain asbestos insulation or
                        electrical transformers cooled by phenylchlorobenzene or
                        biphenyls. Lessor hereby agrees to indemnify Lessee for
                        any liability, costs, damage, loss, claim, expense or
                        cause of action (including but not limited to attorneys'
                        fees and court costs) incurred by or threatened against
                        Lessee as a result of a breach of any of the warranties
                        or representations contained in this paragraph.

            14.5  Prior to the closing, Lessee may, but is not obligated,
                  deliver to Lessor, at its sole discretion and cost, a boundary
                  survey (the "Survey") of the Leased Premises, prepared by a
                  surveyor licensed in Ohio.

                  14.6 At closing, Lessor's title to the Leased Premises shall
                  be good and marketable and free and clear of all liens and
                  encumbrances except: (a) the lien of real estate taxes not
                  then due and payable, (b) easements of record which do not
                  interfere with Lessee's proposed use, and (c) all applicable
                  zoning and building laws, ordinances and regulations. Lessee
                  shall secure and Lessor shall pay for a preliminary title
                  insurance commitment and, after the date of closing, an
                  owner's title insurance policy with extended coverage or
                  comparable form issued by a title insurance company selected
                  by Lessee (the "Title Company") in the amount of the purchase
                  price. The title policy shall insure title to the Leased
                  Premises (including all access, parking and utility easements)
                  in Lessee, free and clear of all liens and encumbrances,
                  except as limited above. If title shall prove defective,
                  Lessor shall perfect the same promptly, but if title cannot be
                  perfected by closing, Lessee may terminate this contract or
                  may, at its election, take title as it then is (with the right
                  to deduct from the purchase price liens or encumbrances of a
                  definite or ascertainable amount), upon giving written notice
                  of such election to Lessor. Marketable title as used herein
                  shall mean title which the Title Company will insure at its
                  regular rates, subject only to standard exceptions and matters
                  referred to in this paragraph.

                                       4
<PAGE>

            14.7  The purchase and sale herein shall be closed on or before
                  January 31, 2005.

            14.8  At the closing, each party shall execute and deliver all
                  documents necessary to effect and complete the closing.

            14.9  Lessor shall pay all conveyance or other taxes payable in
                  connection with the recordation of the general warranty deed.

            14.10 Lessee shall pay all costs of recording the general warranty
                  deed and all other documents related to the transaction.

            14.11 Rent shall be prorated as of the date of closing. Any other
                  prepaid rent previously paid by Lessee to Lessor will be
                  credited to Lessee against the Purchase Price.

            14.12 At the closing, the Lessor shall convey the Leased Premises by
                  general warranty deed and deliver such general warranty deed
                  to the Lessee at the closing. At the closing, Lessor shall
                  deliver to Lessee an affidavit in form reasonably satisfactory
                  to Lessee certifying that Lessor is not a "non-foreign person"
                  which would subject Lessor to withholding tax provisions under
                  Section 1445 of the Internal Revenue Code of 1986 as amended.
                  At closing, Lessor will deliver a lien waiver, acceptable to
                  Lessee and Lessee's title insurer.

            14.13 Ad valorem taxes on the Leased Premises for the year in which
                  the purchase and sale hereunder is closed shall be prorated as
                  of the end of the day of the closing on a calendar year basis.
                  In the event tax bills have not been issued for the year of
                  closing, taxes shall be prorated based on the previous year's
                  tax bill. All income received and expenses incurred with
                  respect to the Leased Premises shall also be prorated as of
                  the date of the closing and appropriate payments or credits
                  made at closing. Lessor shall deliver possession of the Leased
                  Premises to the Lessee on or before the date of closing.

4.    Each party represents to the other that it has had no dealings with any
      realtor, broker or agent in connection with the negotiation of this
      Amendment and each agrees to indemnify and hold the other harmless from
      and against the claims of or liability to any other realtor, broker or
      agent claiming by, through or on behalf of such party with respect to this
      Amendment.

5.    The Lease, as amended, constitutes the entire agreement of the Lessor and
      Lessee with respect to the matters stated in the Lease and may not be
      amended or modified unless such amendment or modification shall be in
      writing and signed by Lessor and Lessee.

6.    The Lease shall be governed in all respects by the laws of the State of
      Ohio.

7.    This Amendment may be executed in one or more counterparts, each of which
      shall be

                                       5
<PAGE>

      deemed to be an original, and all of which, when taken together, shall
      constitute one agreement binding upon the parties thereto.

8.    Except as amended or modified hereby, all terms, covenants and conditions
      of the Lease as heretofore in effect, shall remain in full force and
      effect through the term as extended, and, as amended and modified hereby,
      all of the terms, covenants and conditions of the Lease are hereby
      ratified and confirmed in all respects. In the event of any conflict
      between the terms of this Amendment and the terms of the original Lease,
      the terms of this Amendment shall control.

9.    All capitalized terms used herein, and not otherwise defined, shall have
      the meanings ascribed to said terms in the Lease.

      IN WITNESS WHEREOF, the parties have executed this Second Amendment to
Lease Agreement effective as of the date first set forth above.

LESSOR:                                 LESSEE:

WILLIAM BROOKS REAL ESTATE              ROCKY SHOES & BOOTS, INC.,
COMPANY, an Ohio corporation            an Ohio corporation

By:    /s/ Patricia Brooks Robey        By:      /s/ James E. McDonald
   ---------------------------------       -------------------------------------
   Patricia Brooks Robey                   James E. McDonald
   President                               Vice President and Chief Financial
                                           Officer

                                       6

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