Exhibit 3.1


                      RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                            TRANSDIGM HOLDING COMPANY

            TransDigm Holding Company, a corporation organized under the laws of
the State of Delaware (the "Corporation"), hereby certifies as follows:

            1. The original Certificate of Incorporation of the Corporation was
filed with the Secretary of State of the State of Delaware on September 23,
1993.

            2. The Corporation has not received any payment for any of its
stock.

            3. This Restated Certificate of Incorporation was duly adopted by
the Board of Directors of the Corporation in accordance with the provisions of
Sections 241 and 245 of the General Corporation Law of the State of Delaware.

            4. The original Certificate of Incorporation is hereby amended and
restated in its entirety to read as follows:

            FIRST: The name of the Corporation is TransDigm Holding Company.

            SECOND: The Corporation's registered office in the State of Delaware
      is at Corporation Trust Center, 1209 Orange Street in the City of
      Wilmington, County of New Castle. The name of its registered agent at such
      address is The Corporation Trust Company.

            THIRD: The nature of the business of the Corporation and its purpose
      is to engage in any lawful act or activity for which corporations may be
      organized under the General Corporation Law of the State of Delaware.

            FOURTH: The total number of shares of stock which the Corporation
      shall have authority to issue is 10,000,000 shares, consisting of
      9,000,000 shares of Common Stock, par value $.01 per share (the "Common
      Stock"), and 1,000,000 shares of Class A Common Stock, par value $.01 per
      share (the "Class A Common Stock").

            Except as otherwise provided by this Article or as otherwise
      required by law, shares of Common Stock and Class A Common Stock shall be
      identical and shall entitle the holders thereof to the same rights and
      privileges, subject to the same qualifications, limitations and
      restrictions.

                  1. Voting Rights. Except as otherwise required by applicable
            law, the holders of Common Stock will be entitled to one vote per
            share on all matters 


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            to be voted on by the Corporation's stockholders, and the holders of
            Class A Common Stock will have no voting rights.

                  2. Dividends. When and as dividends are declared thereon,
            whether payable in cash, property or securities of the Corporation,
            the holders of Common Stock and the holders of Class A Common Stock
            will be entitled to share equally, share for share, in such
            dividends, provided, however, that if dividends are declared which
            are payable in shares of Common Stock or Class A Common Stock,
            dividends will be declared which are payable at the same rate on
            each class of stock, and the dividends payable in shares of Common
            Stock will be payable only to holders of Common Stock, and the
            dividends payable in shares of Class A Common Stock will be payable
            only to holders of Class A Common Stock.

                  3. Conversion and Exchange. (a) Upon the occurrence of any
            Conversion Event, each record holder of Class A Common Stock shall
            be entitled to convert into the same number of shares of Common
            Stock any or all of the shares of such holder's Class A Common Stock
            being sold, distributed or otherwise disposed of or converted in
            connection with the occurrence of such Conversion Event. For
            purposes of this Section 3, (i) a "Conversion Event" shall mean any
            transfer of shares of Class A Common Stock to any person or persons
            who are not affiliates of the transferor, including, without
            limitation, pursuant to any public offering or public sale of
            securities of the Corporation (including a public offering
            registered under the Securities Act of 1933 and a public sale
            pursuant to Rule 144 under the Securities Act or 1933 or any similar
            rule then in force), (ii) a "person" shall mean any natural person
            or any corporation, partnership, joint venture, trust,
            unincorporated organization and any other entity or organization,
            and (iii) an "affiliate", with respect to any person, shall mean
            such person's spouse, parents, members of such person's family or
            such person's lineal descendents and any other person that directly,
            or indirectly through one or more intermediaries, controls, or is
            controlled by, or is under common control with such person. In
            addition, all of the Corporation's Class A Common Stock shall be
            automatically and mandatorily converted into the same number of
            shares of Common Stock without any action on the part of any holder
            upon notice to such effect by the Corporation to the record holders
            of Class A Common Stock.

                  (b) Subject to Section 3(a), each conversion of shares of
            Class A Common Stock into shares of Common Stock at the option of
            the holder shall be effected by the surrender of the certificate or
            certificates representing the shares to be converted at the
            principal office of the Corporation at any time (including within a
            reasonable time prior to the occurrence of any Conversion Event, if
            necessary to effect the conversion of shares related thereto,
            provided, however, that the holders of such shares will not be
            entitled to vote on any matters to be voted on by the Corporation's
            stockholders during such interim period, such certificates being
            deemed to represent only shares of Class A Common Stock for such
            purpose) during normal business hours, together with a written
            notice by the 


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            holder of such Class A Common Stock stating that a Conversion Event
            has occurred or is about to occur and that such holder desires to
            convert the shares, or a stated number of the shares, of such Class
            A Common Stock represented by such certificate or certificates into
            shares of Common Stock (and including instructions for issuance of
            the Common Stock to be issued upon such conversion). Each conversion
            at the option of the holder shall be deemed to have been effected as
            of the close of business on the later of (i) the date on which the
            Conversion Event has occurred and (ii) the date on which such
            certificate or certificates have been surrendered and such notice
            has been received, and at such later time the rights of the holder
            of the converted Class A Common Stock, as a holder of Class A Common
            Stock, shall cease and the person or persons in whose name or names
            the certificate or certificates for shares of Common Stock are to be
            issued upon such conversion shall be deemed to have become the
            holder or holders of record of the shares represented thereby.
            Promptly after the Conversion Event has occurred and the surrender
            of certificates and the receipt of written notice, the Corporation
            shall issue and deliver in accordance with the surrendering holder's
            instructions (x) the certificate or certificates for the shares of
            Common Stock issuable upon such conversion and (y) a certificate
            representing any shares of Class A Common Stock which were
            represented by the certificate or certificates delivered to the
            Corporation in connection with such conversion but which were not
            converted. If any shares of Class A Common Stock are converted into
            shares of Common Stock in connection with a conversion Event and
            such shares of Common Stock are not actually sold, distributed or
            otherwise disposed of so that a Conversion Event does not actually
            occur, such shares of Common Stock shall be automatically converted
            back into the same number of shares of Class A Common Stock.

            Any mandatory conversion of shares of Class A Common Stock into
            Common Stock shall be effected by the Corporation delivering to the
            holders of such shares, to the last address appearing for such
            holders on the books of the Corporation, written notice to the
            effect that the Board of Directors has determined to mandatorily
            convert the Class A Common Stock into Common Stock and upon and
            after such notice all of the shares of Class A Common Stock so
            converted shall be deemed to be no longer outstanding, any right to
            receive dividends thereon shall cease and all rights and privileges
            with respect to the Class A Common Stock so converted shall cease
            except for the right of the holder thereof to receive any previously
            declared but unpaid dividends on the Class A Common Stock, and the
            certificates which theretofore had represented Class A Common Stock
            shall for all purposes represent only Common Stock; provided,
            however, no dividends on the Common Stock shall be paid to such
            holder unless and until the certificates for the Class A Common
            Stock have been surrendered to the Corporation, which shall upon
            such surrender issue certificates for the Common Stock to such
            holder and pay to such holder any dividends on the Common Stock
            which have been declared as of a record date, and which otherwise
            would have 


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            been paid, since the date the shares of Class A Common Stock were
            deemed to be converted.

                  (c) The issuance of certificates upon conversion will be made
            without charge to the holders of such shares for any issuance tax in
            respect thereof or other cost incurred by the Corporation in
            connection with such conversion, except that the holder of any such
            shares shall be responsible for the payment of all applicable
            transfer taxes if the shares of Common Stock are issued in the name
            of a person or persons other than such holder.

                  (d) The Corporation shall at all times reserve and keep
            available out of its authorized but unissued shares of Common Stock
            solely for the purpose of issuance upon the conversion of the Class
            A Common Stock, such number of shares of Common Stock issuable upon
            the conversion of all outstanding Class A Common Stock. All shares
            of Common Stock which are so issuable shall, when issued, be duly
            and validly issued, fully paid and non-assessable and free from all
            taxes, liens and charges. The Corporation shall take all such
            actions as it deems necessary or appropriate to assure that all such
            shares of Common Stock may be so issued without violation of any
            applicable law or governmental regulation or any requirements of any
            domestic securities exchange upon which shares of Common Stock may
            be listed.

                  (e) Except as provided in the last sentence of the first
            paragraph of section 3(b), shares of Class A Common Stock that are
            converted into shares of Common Stock as provided herein shall be
            retired and cancelled and shall not be reissued.

                  4. Stock Splits, etc. If the Corporation in any manner
            subdivides (by stock split, stock dividend or otherwise) or combines
            (by reverse stock split or otherwise) the outstanding shares of
            either class of stock, the outstanding shares of the other class of
            stock will be proportionately subdivided or combined, as the case
            may be, and effective provision shall be made by the Board of
            Directors of the Corporation (whose determination with respect
            thereto will be final and binding) for the protection of all
            conversion rights hereunder.

                  5. Merger or Consolidation. In any merger, consolidation or
            business combination of the Corporation with or into another
            corporation, whether or not the Corporation is the surviving
            corporation, the consideration per share to be received by holders
            of either Common Stock or Class A Common Stock in such merger,
            consolidation or business combination shall be identical to that
            received by holders of the other class of stock.

                  6. Liquidation. Upon any voluntary or involuntary liquidation,
            dissolution or winding-up of the affairs of the Corporation, after
            payment or provision for payment of the debts and other liabilities
            of the Corporation, the remaining assets of the Corporation
            available for distribution shall be divided 


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            among and paid ratably to the holders of Common Stock and Class A
            Common Stock as a single class. For the purposes hereof, the
            voluntary sale, conveyance, exchange or transfer (for cash, shares
            of stock, securities or other consideration) of all or substantially
            all the property or assets of the Corporation shall be deemed a
            voluntary liquidation, dissolution or winding up of the Corporation,
            but a consolidation or merger of the Corporation with one or more
            other corporations shall not be deemed to be a liquidation,
            dissolution or winding up, voluntary or involuntary.

            FIFTH: The following provisions are inserted for the management of
      the business and for the conduct of the affairs of the Corporation and for
      the purpose of creating, defining, limiting and regulating the powers of
      the Corporation and its directors and stockholders:

                  (a) The number of directors of the Corporation shall be fixed
            and may be altered from time to time in the manner provided in the
            By-Laws, and vacancies in the Board of Directors and newly created
            directorships resulting from any increase in the authorized number
            of directors may be filled, and directors may be removed, as
            provided in the By-Laws.

                  (b) The election of directors may be conducted in any manner
            approved by the stockholders at the time when the election is held
            and need not be by ballot.

                  (c) All corporate powers and authority of the Corporation
            (except as at the time otherwise provided by law, by this
            Certificate of Incorporation or by the By-Laws) shall be vested in
            and exercised by the Board of Directors.

                  (d) The Board of Directors shall have the power without the
            assent or vote of the stockholders to adopt, amend, alter or repeal
            the By-Laws of the Corporation, except to the extent that the
            By-Laws or this Certificate of Incorporation otherwise provide.

                  (e) No director of the Corporation shall be liable to the
            Corporation or its stockholders for monetary damages for breach of
            his or her fiduciary duty as a director, provided that nothing
            contained in this Article shall eliminate or limit the liability of
            a director (i) for any breach of the director's duty of loyalty to
            the Corporation or its stockholders, (ii) for acts or omissions not
            in good faith or which involve intentional misconduct or a knowing
            violation of the law, (iii) under Section 174 of the General
            Corporation Law of the State of Delaware or (iv) for any transaction
            from which the director derived an improper personal benefit.

            SIXTH: The Corporation reserves the right to amend or repeal any
      provision contained in this Certificate of Incorporation in the manner now
      or hereafter prescribed 


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      by the laws of the State of Delaware, and all rights herein conferred upon
      stockholders or directors are granted subject to this reservation.


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            IN WITNESS WHEREOF, the undersigned officers of the Corporation have
executed this certificate on the 23rd day of September, 1993.



                                    /s/ David I. Wahrhaftig
                                    -------------------------
                                    David I. Wahrhaftig
                                    Vice President
ATTEST:


/s/ Peter F. Schweinfurth
- -------------------------
Peter F. Schweinfurth
Assistant Secretary


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