STC SA3431NM

This Certificate issued to AIRWELD, INC.

8167 BELEDERE AVENUE, SUITE D SACRAMENTO, CALIFORNIA 95826 Part 4B of the Civil Aviation Regulations.

(See T. C. Data Sheet) Original Product Type Certificate Number :

4A28 Boeing 720-023B Description of Type Design Change: Installation of Garrett GTCP-85-98CK Auxiliary Power Unit in the forward baggage compartment in accordance with FAA approved World Airways Inc., Master Drawing List No. 497000, Revision N/C, dated September 26, 1986, or later FAA approved revision. FAA approved Airplane Flight Manual Supplement No. FMS 491-7 date d June 10, 1987, or later FAA approved revision is required.

Limitations and Conditions: This installation is approved for ground operation only. The approval of this change in type design applies to the aforementioned ai rcraft model only. This modification should not be incorporated in any aircraft unless it is determined th at the interrelationship between this change and any previously approved modifications will not introduce an y adverse effect upon the airworthiness of the above listed aircraft. If the holder agrees to permit another pe rson to use this certificate to alter the product, the holder shall give the other person written evidence of that permission.

This certificate and the supporting data, which is the basis for approval, shall remain in effect until surrendered, suspended, revoked or a termination date is otherwise established by the Administrator of the Federal Aviation Administration.

Date of application: February 3, 1986

Date of issuance: June 16, 1987

Date reissued: November 24, 1987; July 16, 1997;

January 5, 2000; December 3, 2001; April 28, 2008

( Signature) Manager, Propulsion Branch Los Angeles Aircraft Certification Office ( Title)

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Number (STC No.)