STC SR00231SE

Brep United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number SROO231SE This certificate issued to: Columbia Helicopters P.O. Box 3500 Portland, OR 97208 Certifies that the change in the type design for the following product with the limitations and conditions therefor as specified hereon meets the airworthiness requivements of Part 21.25(a)(2) and (b)of the Federal Aviation Regulations Original Product -Type Certificate Number: H40NM Make Sikorsky Nodet CH-54A, Restricted Category only Description of Type Design Change: . Relocation of the existing transmission oil cooler and blower, and a change in the oil cooler drive system from a belt drive to hydraulic motor drive in accordance with an FAA approved copy of Columbia Drawing List No. C54T0016, Revision "F", dated February 21, 1996, or later FAA approved revisions.

Limitations and Conditions: Approval of this change in type design applies to basic Sikorsky Model CH-54A helicopters as defined on Restricted Category Type Certificate No. H40NM. This approval should not be extended to aircraft of this model on which other previously approved modifications are incorporated unless it is determined by the installer that the relationship between this change and any of those other previously approved modifications, including changes in type design, will introduce no adverse effect upon the airworthiness of that rotorcraft.

Rotorcraft equipment with this transmission oil cooler system must operated be in accordance with Columbia Rotorcraft Flight Manual Supplement No. CHI-54-RFMS-6, dated March 6, 1998, or later FAA approved revision.

The modified rotorcraft must be maintained in accordance with Columbia Maintenance Manual No. C54T0023, Revision "A", revised February 28, 1996, or later FAA approved revision.

NOTE: None of the basic rotorcraft operating limitations have been changed by virtue of this installation.

If the holder agrees to permit another person to use this certificate to alter the product, the holder shall give the other person written evidence of that permission.

Date of Application: September 17, 1993 Date Reissued:

Date of Issuance: September 5, 1995 Date Amended: February 28, 1996, March 6, 1998 FEDERAL AVIATION By otion of the Sad stra Le (Signature) HOMINIS TRATOR Acting Manager, Seattle Aircraft Certification Office (Title)

FAA FORM 8110-2(10-6B)