# STC SR00449SE

- Type: Supplemental type certificate
- Status: Current, Amended
- Holder: Columbia Helicopters Inc, United States
- Description: Replacement of oil in main transmission, intermediate gearbox and tail gearbox with Mobil SHC 627 synthetic bearing and gear lubricants
- Applied: July 18, 1995
- Status date: March 18, 1999
- Product: Aircraft, Rotorcraft
- Certification basis: Part 21
- Data sheets: [TCDS H40NM](https://openairdocs.org/tcds/H40NM)
- Certificate PDF: https://openairdocs.org/files/sha256/1f/cf/1fcff6e1bf7f645490c4c83d512b8c34c909213192234e235fe6f2f07ddb7e68
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/0F580CDB08DB1437862579A70070D205.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SR00449SE

## ADs that name it (0)

None.

## Approved models (1)

- Erickson Air-Crane Company CH-54A ([TCDS H40NM](https://openairdocs.org/tcds/H40NM))

## What the certificate says

This is OCR from the scanned FAA certificate. OCR can misread letters and numbers.

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number SRO0449SE This certificate issued to: Columbia Helicopters P.O. Box 3500 Portland, OR 97208 Part 21.25(a)(2) and (b)of the Federal Aviation Regulations.

Original Product -Type Certificate Number: H40NM Make: Sikorsky Model: CH-54A (Restricted Category Only) Description of Type Design Change: Replacement of the oil in the main transmission, intermediate gearbox and tail gearbox with Mobil SHC 626 or 627 synthetic bearing and gear lubricants.

Limitations and Conditions: Approval of this change in type design applies to basic Sikorsky Model CH-54A rotorcraft as defined on Restricted Category Type Certificate No. H40NM. This approval should not be extended to rotorcraft 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. Only those rotorcraft equipped with Sikorsky main transmission P/N 6435-20400-058, intermediate gearbox P/N 6435-66400-044 and tail gearbox P/N 6435-66500-043 are eligible for this oil change. A copy of this certificate must be maintained as part of the permanent records for the modified rotorcraft.

NOTE: None of the basic rotorcraft operating limitations have been changed by virtue of this installation. No change to the basic maintenance or flight manuals is deemed necessary 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: July 18, 1995 Date Reissued:

Date of Issuance: June 20, 1997 Date Amended: March 18, 1999 FEDERAL AVIATION By unistrator (Signature) TOMINIST RATION Acting Manager, Seattle Aircraft Certification Office (Title)

47.

**FAA FORM B110-2(10-68)**

## Every issue (1)

- March 18, 1999: Amended, Current. [certificate](https://openairdocs.org/files/sha256/1f/cf/1fcff6e1bf7f645490c4c83d512b8c34c909213192234e235fe6f2f07ddb7e68)

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