<PAGE>
                                                                   EXHIBIT 10.4A

                            FOURTH AMENDMENT TO LEASE
                                   (901 Lease)

     This Fourth Amendment to Lease (this "Agreement") is entered into this 27
day of July, 1994, by and between Korry Electronics Co., a Delaware corporation
("Korry") and Houg Family Partnership ("HFP"), a Washington limited partnership.

                                    RECITALS

     a. HFP's predecessor, 901 Dexter Avenue Associates, and Korry's
predecessor, Criton Technologies ("CT"), a Delaware general partnership, entered
into an industrial lease agreement (the "Original Lease") dated July 17, 1974,
under the terms of which CT, as tenant, leased certain property (the "Premises")
located at 901 Dexter Avenue North, Seattle, Washington. The Original Lease has
been amended by three amendments, dated respectively May 10, 1985 (the "First
Amendment"), June 20, 1986 (the "Second Amendment"), and September 1, 1987 (the
"Third Amendment"). The Original Lease, as amended by these three amendments, is
hereinafter designated as the "Amended Lease."

     b. HFP succeeded to the landlord's interest under the Amended Lease on it
acquired title to the Premises on April 17, 1989. Korry succeeded to the
lessee's interest under the Amended Lease pursuant to an assignment dated
September 27, 1989.

     c. The parties wish to amend the Amended Lease under the terms and
conditions set forth below.

                              TERMS AND CONDITIONS

     1. Term of Occupancy; Termination. The Lease term is hereby extended to
July 31, 2011, and Korry shall have the sole and exclusive right to peaceful and
quiet enjoyment of the Premises, and to occupy the Premises without interruption
or interference for the entire remainder of the term as extended hereby.
However, Korry shall have the right to terminate the Lease at any time by giving
written notice to HFP at least two years in advance of the termination date.
Korry shall not be liable for any obligations arising under or in connection
with the Lease following the date specified as the termination date.

     2. Notices. Paragraph 19 of the Original Lease is hereby deleted and
replaced by the following:

          a. Notice Addresses. Any notice, keys, drawings, or other item or
          items that may or shall be delivered pursuant to the terms of this
          Lease shall be delivered to the following addresses:

<PAGE>

          If to Landlord, to the following:

             Houg Family Partnership
             c/o Dr. Andrew Houg
             11066 5th Avenue N.E.
             Seattle, WA 98125

          If to Tenant, to the following:

             Korry Electronics Co.
             901 Dexter Avenue North
             Seattle, WA 98109
             Attn: Director of Finance

          b. Form of Notice and Delivery. Any and all notices shall be in
          writing and either delivered by hand or mailed, via certified United
          States mail, postage prepaid, to the addresses of the respective
          recipient as set forth above. Delivery shall be deemed complete and
          effective upon receipt by the addressee or upon the third business day
          following mailing, whichever shall first occur.

          c. Covenant to Accept Notice. Neither party shall refuse or otherwise
          attempt to avoid delivery of any notice.

          d. Change of Notice Address. Either party may change its notice
          address by giving written notice of a new address in accordance with
          the foregoing notice provisions.

     3. Continuation of Unmodified Terms. Except as modified by this Agreement,
the terms of the Amended Lease remain in full force and effect. In the event of
conflict or inconsistency between the provisions of the Amended Lease and the
provisions of this Agreement, this Agreement will control.

     4. Binding Effect. The terms and conditions of this Agreement shall be
binding upon and inure to the benefit of the parties hereto and their respective
successors and permitted assigns.

     5. Entire Agreement. This Agreement contains the entire understanding
between and among the undersigned parties in connection with the subject matter
addressed herein. It supersedes and replaces any and all prior negotiations,
agreements, discussions, representations, statements and promises, whether oral
or written. Each party hereby acknowledges that no promise, representation or
warranty whatsoever, express or implied, has been made by any other party or
agent or attorney of any other party to induce it to execute this document,
other than the terms expressly stated in this written Agreement.


                                       -2-

<PAGE>

     6. Construction of this Agreement.

          a. This Agreement shall be governed by and construed in accordance
          with the laws of the State of Washington.

          b. The paragraph headings used in this Agreement are inserted for
          convenience only and are not intended to be a part of this Agreement
          or to affect its construction.

          c. When used in this Agreement, terms such as "herein," "hereto," and
          "hereof" refer to the entire Agreement, and are not limited to any
          portion or portions hereof.

          d. The language of this Agreement, including without limitation any
          ambiguities, shall not be construed in favor of any party or against
          any other party.

          e. Time is of the essence in this Agreement.

          f. This Agreement is exclusively for the benefit of the undersigned
          parties, and no intent to benefit any third person or entity shall be
          inferred, implied, or presumed in construing this Agreement.

     7. Signing Authority. Each of the individuals signing below on behalf of
one of the parties warrants that he is authorized to sign this Agreement on that
party's behalf and that his signature binds that party to this Agreement.

     Dated the day and year first set forth above.

KORRY ELECTRONICS CO.                   HOUG FAMILY PARTNERSHIP


by /s/ David Elkins                     by /s/ Andrew Houg
   ----------------------------------      -------------------------------------
   David Elkins                            Andrew Houg
   President                               Managing General Partner


ESTERLINE TECHNOLOGIES, INC.


by /s/ R. W. Stevenson
   ----------------------------------
   R. W. Stevenson - Chief Financial
   Officer


                                       -3-