STC SA3505WE

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number: SA3505NE This certificate issued to: Northwest Airlines, Inc.

2700 Lone Oak Parkway Eagan, MN 55124 Part 4b of the CIVIT Air Regulations:

Original Product - Type bertificate Number: AЗWE Make: Boeing Model: 727-2M7 Installation of Ground Proximity Warning System in accordance with FAA sealed Hughes Airwest Top Drawing No. RW3450014 N/C or later FAA sealed revision.

Hughes Airwest FAA Approved Airplane Flight Manual Supplement dated October 5, 1977, to Boeing Airplane Flight Manual Document D68728.2M7 is required as part of this installation.

The approval of this change in type design applies basically to the above listed This approval should not be extended to other aircraft of this model on which other previously approved modifications are incorporated unless it is determined by the installer that the interrelationship between this change and any of those other previously approved modifications will introduce no adverse effect upon the airworthiness of that aircraft.

Date of Application: September 8, 1977 Date Reissued: October 13, 1982 November 14, 1986 Date of Issuance: October 27, 1977 Date Amended:

FEDERAL AVIATION Bardirector Athe Administrator W. F. Horn * (Signature ) TMINISTRATO Manager, Chicago Aircraft Certification Office, ACE-115C, Central Region, FAA (Title)