SCHEDULE 13G

Amendment No. 1
Gencorp Incorporated
common stock
Cusip # 368682100
Filing Fee: No


Cusip # 368682100
Item 1:   Reporting Person - FMR Corp. - (Tax ID:  04-2507163)
Item 4:   Commonwealth of Massachusetts
Item 5:   115,797
Item 6:   None
Item 7:   479,489
Item 8:   None
Item 9:   479,489
Item 11:  1.50%
Item 12:  HC 




Cusip # 368682100
Item 1:   Reporting Person - Edward C. Johnson 3d - (Tax ID:  029-24-9996)
Item 4:   United States of America
Item 5:   None
Item 6:   None
Item 7:   479,489
Item 8:   None
Item 9:   479,489
Item 11:  1.50%
Item 12:  IN 




SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)


Item 1(a).    Name of Issuer:

         Gencorp Incorporated

Item 1(b).    Name of Issuer's Principal Executive Offices:

         175 Ghent Road
         Fairlawn, OH  44333-3300

Item 2(a).    Name of Person Filing: 

         FMR Corp.

Item 2(b).    Address or Principal Business Office or, if None, Residence:

         82 Devonshire Street, Boston, Massachusetts  02109

Item 2(c).    Citizenship:

         Not applicable

Item 2(d).    Title of Class of Securities:

         Common Stock

Item 2(e).    CUSIP Number:  

         368682100

Item 3.  This statement is filed pursuant to Rule 13d-1(b) or 13d-2(b) and the
person filing, FMR Corp., is a parent holding company in accordance
with Section 240.13d-1(b)(ii)(G).  (Note:  See Item 7).

Item 4.  Ownership

         (a)  Amount Beneficially Owned:    479,489

         (b)  Percent of Class:   1.50%

         (c)  Number of shares as to which such person has:  

              (i)   sole power to vote or to direct the vote:   115,797

              (ii)  shared power to vote or to direct the vote: None

              (iii) sole power to dispose or to direct the disposition of:
    479,489

              (iv)  shared power to dispose or to direct the disposition
of: None




Item 5.  Ownership of Five Percent or Less of a Class.

         If this statement is being filed to report the fact that as
of the date hereof, the reporting person has ceased to be
the beneficial owner of more than five percent of the class
of securities, check the following (X).

Item 6.  Ownership of More than Five Percent on Behalf of Another Person.

         Not applicable.

Item 7.  Identification and Classification of the Subsidiary Which Acquired
the Security Being Reported on By the Parent Holding Company.

         See attached Exhibit(s) A, B, and C.

Item 8.  Identification and Classification of Members of the Group.

         Not applicable, see attached Exhibit A. 

Item 9.  Notice of Dissolution of Group.

         Not applicable.


Item 10. Certification.

         Inasmuch as the reporting persons are no longer the beneficial
owners of more than 5% of the number of shares outstanding, the
reporting persons have no further reporting obligation under
section 13(d) of the Securities and Exchange Commission
thereunder, and the reporting persons have no obligation to amend
this Statement if any material change occurs in the facts set
forth herein.


Signature

         After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this statement
is true, complete and correct. 



    February 11, 1994   
Date



    /S/Arthur S. Loring
Signature



    Arthur S. Loring, Vice President
    
Name/Title




SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)

    Pursuant to the instructions in Item 7 of Schedule 13G, Fidelity
Management & Research Company ("Fidelity"), 82 Devonshire Street, Boston,
Massachusetts 02109, a wholly-owned subsidiary of FMR Corp. and an
investment adviser registered under Section 203 of the Investment Advisers
Act of 1940, is the beneficial owner of 360,292 shares or 1.13% of the
common stock outstanding of Gencorp Incorporated ("the Company") as a
result of acting as investment adviser to several investment companies
registered under Section 8 of the Investment Company Act of 1940.  The
number of shares of common stock of Gencorp Incorporated owned by the 
investment companies at December 31, 1993 included 124,492 shares of common
stock resulting from the assumed conversion of $2,000,000 principal amount
of 8% Convertible Subordinated Debentures (62.24699 shares of common stock
for each $1,000 principal amount of debenture).

    Edward C. Johnson 3d, FMR Corp., through its control of Fidelity, and
the Funds each has sole power to dispose of the 360,292 shares owned by the
Funds.

    Neither FMR Corp. nor Edward C. Johnson 3d, Chairman of FMR Corp., 
has the sole power to vote or direct the voting of the Shares owned
directly by the Fidelity Funds, which power resides with the Funds' Boards
of Trustees.  Fidelity carries out the voting of the Shares under written
guidelines established by the Funds' Boards of Trustees.

    Fidelity Management Trust Company, 82 Devonshire Street, Boston,
Massachusetts 02109, a wholly-owned subsidiary of FMR Corp. and a bank as
defined in Section 3(a)(6) of the Securities Exchange Act of 1934, is the
beneficial owner of 75,197 shares or 0.24% of the common stock outstanding
of the company as a result of its serving as investment manager of the
institutional account(s).  The number of shares of common stock of Gencorp
Incorporated owned by the institutional account(s) at December 31, 1993
included 49,797 shares of common stock resulting from the assumed
conversion of $800,000 principal amount of the Convertible Subordinated
Debentures described above.

    FMR Corp., through its control of Fidelity Management Trust Company,
has sole dispositive power over 75,197 Shares and sole power to vote or to
direct the voting of 71,797 shares, and no power to vote or to direct the
voting of 3,400 Shares of common stock owned by the institutional
account(s) as reported above.

    Edward C. Johnson 3d owns 34.0% of the outstanding voting common stock
of FMR Corp.  Mr. Johnson 3d is Chairman of FMR Corp.  Various Johnson
family members and trusts for the benefit of Johnson family members own FMR
Corp. voting common stock.  These Johnson family members, through their
ownership of voting common stock, form a controlling group with respect to
FMR Corp.

    Fidelity International Limited, Pembroke Hall, 42 Crowlane, Hamilton,
Bermuda, and various foreign-based subsidiaries provide investment advisory
and management services to a number of non-U.S. investment companies (the
"International Funds") and certain institutional investors.  Fidelity
International Limited is the beneficial owner of 44,000 shares or 0.14% of
the common stock outstanding of the company.  Additional information with
respect to the beneficial ownership of Fidelity International Limited is
shown on Exhibit B, page 10.


SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)


    Pursuant to instructions in Item 7 of Schedule 13G, this Exhibit has
been prepared  to identify Fidelity International Limited, Pembroke Hall,
42 Crow Lane, Hamilton, Bermuda, a Bermudian joint stock company
incorporated for an unlimited duration by private act of the Bermuda
Legislature (FIL) and an investment adviser to various investment companies
(the "International Funds") and certain institutional investors, as the
beneficial owner of 44,000 shares or 0.14% of the common stock outstanding
of Gencorp Incorporated.

    Prior to June 30, 1980, FIL was a majority-owned subsidiary of
Fidelity Management & Research Company (Fidelity), a wholly-owned
subsidiary of FMR Corp.  On that date, the shares of FIL held by Fidelity
were distributed, as a dividend,  to the shareholders of FMR Corp.  FIL
currently operates as an entity independent of FMR Corp. and Fidelity.  The
International Funds and FIL's other clients, with the exception of Fidelity
and an affiliated company of Fidelity, are non-U.S. entities.

    A partnership controlled by Edward C. Johnson 3d and members of his
family owns shares of FIL voting stock with the right to cast approximately
48.879% of the total votes which may be cast by all holders of FIL voting
stock.  Mr. Johnson 3d is Chairman of FMR Corp. and FIL.  FMR Corp. and FIL
are separate and independent corporate entities.  FMR Corp. and FIL are
managed independently and their Boards of Directors are generally composed
of different individuals.  Their investment decisions are made
independently, and their clients are different organizations.

    FMR Corp. and FIL are of the view that they are not acting as a
"group" for purposes of Section 13(d) under the Securities Exchange Act of
1934 (the "1934" Act) and that they are not otherwise required to attribute
to each other the "beneficial ownership" of securities "beneficially owned"
by the other corporation within the meaning of Rule 13d-3 promulgated under
the 1934 Act.  Therefore, they are of the view that the shares held by the
other corporation need not be aggregated for purposes of Section 13(d).
However, FMR Corp. is making this filing on a voluntary basis as if all of
the shares are beneficially owned by FMR Corp. and FIL on a joint basis.

    FIL may continue to have the International Funds or other accounts
purchase shares subject to a number of factors, including, among others,
the availability of shares for sale at what FIL considers to be reasonable
prices and other investment opportunities that may be available to the
International Funds.

    FIL intends to review continuously the equity position of the
International Funds and other accounts in the Company.  Depending upon its
future evaluations of the business and prospects of the Company and upon
other developments, including, but not limited to, general economic and
business conditions and money market and stock market conditions, FIL may
determine to cease making additional purchases of shares or to increase or
decrease the equity interest in the Company by acquiring additional shares,
or by disposing of all or a portion of the shares.

    FIL does not have a present plan or proposal which relates to or would
result in (i) an extraordinary corporate transaction, such as a merger,
reorganization, liquidation, or sale or transfer of a material amount of
assets involving the Company or any of its subsidiaries, (ii) any change in
the Company's present Board of Directors or management, (iii) any material
changes in the Company's present capitalization or dividend policy or any
other material change in the Company's business or corporate structure,
(iv) any change in the Company's charter or by-laws, or (v) the Company's
common stock becoming eligible for termination of its registration pursuant
to Section 12(g)(4) of the 1934 Act.

    FIL has the sole power to vote and the sole power to dispose of the
shares.


SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)

RULE 13d-1(e)  AGREEMENT

    The undersigned persons, on February 11, 1994, agree and consent to
the joint filing on their behalf of this Schedule 13G in connection with
their beneficial ownership of the common stock of Gencorp Incorporated at
December 31, 1993.

    FMR Corp.
    By   /S/Arthur S. Loring
Arthur S. Loring
Vice President - Legal
         Edward C. Johnson 3d
    By   /S/Arthur S. Loring
Arthur S. Loring
Under Power of Attorney
dated 5/17/89
On File with Schedule 13G
for
Airborne Freight Corp.
9/10/91
    Fidelity Management & Research Company
    By   /S/Arthur S. Loring
Arthur S. Loring
Sr. V.P. and General
Counsel