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                                                                     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. This Restated Certificate of Incorporation was duly adopted
         by the Board of Directors of the Corporation and approved by its
         stockholders on May 31, 2001 in accordance with the provisions of
         Sections 242 and 245 of the General Corporation Law of the State of
         Delaware.

                  3. The 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 capital stock which the
         Corporation shall have authority to issue is 1,075,000, consisting of
         900,000 shares of Common Stock, par value $.01 per share (the "COMMON
         STOCK"), 100,000 shares of Class A Common Stock, par value $.01 per
         share (the "CLASS A COMMON STOCK"), and 75,000 shares of Preferred
         Stock, par value $.01 per share (the "PREFERRED 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.

                  The Board of Directors of the Corporation is expressly
authorized to provide for the issuance of all or any shares of the Preferred
Stock in one or more classes or series, and to fix for each such class or series
such distinctive designations and such powers, preferences and rights and such
qualifications, limitations or restrictions thereof, as shall be stated and
expressed in the resolution or resolutions adopted by the Board of Directors
providing for the issuance of


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such class or series and as may be permitted by the General Corporation Law of
the State of Delaware.

         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 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) . (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 of 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 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



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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 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



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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
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.



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                  (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 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 officer of the Corporation
has executed this certificate on the 31st day of May, 2001.

                                                /s/ Gregory Rufus
                                                -------------------------------
                                                Gregory Rufus
                                                Chief Financial Officer



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