# STC SH4909NM

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Cascade STC LLC, United States
- Description: Replace the aft engine compartment heat blanket with a stainless steel firewall.
- Applied: December 11, 1989
- Status date: December 22, 2015
- Product: Aircraft, Rotorcraft
- Certification basis: Part 21
- Data sheets: [TCDS H3WE](https://openairdocs.org/tcds/H3WE)
- Certificate PDF: https://openairdocs.org/files/sha256/79/99/79998562900774f3d0f8c4c4d8915b23d2354a059e6168f2732f4f28ffa74bac
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B0698862329CF6B486257F25005D8FB5.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SH4909NM

## ADs that name it (0)

None.

## Approved models (12)

- MD Helicopters Inc. 369 ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 369A ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 369D ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 369E ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 369F ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 369FF ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 369H ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 369HE ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 369HM ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 369HS ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 500N ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))
- MD Helicopters Inc. 600N ([TCDS H3WE](https://openairdocs.org/tcds/H3WE))

## What the certificate says

Read from the PDF's text layer, without the form's printed wording; the layout is lost and the order can differ. The PDF is the record.

Number SH4909NM

This certificate, issued to Cascade STC, LLC 4824 S 283rd Place Auburn, WA 98001

Part 6 of the Civil Air Regulations.

including Amendments 6-1 through 6-4 with special conditions and equivalent level of safety provisions as listed in the type certificate.

Original ProductType Certificate Number: H3WE Make: MDHI (HUGHES) Model: 369 (Army YOH-6A), 369A (Army OH-6A), 369H, 369HM, 369HS, 369HE, 369D, 369E, 369F, 369FF 500N, 600N

Description of the Type Design Change: Replace the aft engine compartment heat blanket with a stainless steel firewall in accordance with Cascade Airframe Repair, Inc. Drawing List No. CAR-5040, Revision 3, dated June 9, 1998, or later Federal Aviation Administration approved revision.

Limitations and Conditions: Approval of this change in type design applies to the above model rotorcraft only.

This approval should not be extended to other rotorcraft on which other previously approved modifications are incorporated unless it is determined 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. A copy of this certificate must be maintained as part of the permanent records for the modified rotorcraft.

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: December 11, 1989 Date reissued: April 9, 2014; December 22, 2015 Date of issuance: March 21, 1990 Date amended: 10/13/95; 12/17/98

(Signature)

Manager, Seattle Aircraft Certification Office (Title)

## Every issue (3)

- December 22, 2015: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/79/99/79998562900774f3d0f8c4c4d8915b23d2354a059e6168f2732f4f28ffa74bac)
- April 9, 2014: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/fd/03/fd03fd903f03134b8bad6fa715732d86546edbf1dd6ad00083b46f642fef89a5)
- December 17, 1998: Amended, Historical. [certificate](https://openairdocs.org/files/sha256/fa/e8/fae80516c1afb31b329bea3a2c1c1bdc185a61fe150110f673a45180a2172b14)

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