# STC SR00788DE - Type: Supplemental type certificate - Status: Current, Amended - Holder: Billings Flying Service Inc., United States - Description: Installation of Bubble Windows on BFS CH-47D Chinook Rotorcraft for Left and Right sides of the Pilot and Co-Pilot doors respectively - Applied: September 22, 2014 - Status date: June 6, 2025 - Product: Aircraft, Rotorcraft - Certification basis: Part 29 - Data sheets: [TCDS R0011DE](https://openairdocs.org/tcds/R0011DE), [TCDS R0014DE](https://openairdocs.org/tcds/R0014DE), [TCDS R00115SE](https://openairdocs.org/tcds/R00115SE), [TCDS R0015DE](https://openairdocs.org/tcds/R0015DE) - Certificate PDF: https://openairdocs.org/files/sha256/51/7e/517e315585b2ddc263f10fdc7d5a95156b6484030553865d2d8a05b7e1c56cbe - Approved model list and other attachments: [SR00788DE_AML.pdf](https://openairdocs.org/files/sha256/30/89/3089359d74ac02b6129f691fa33bd2cb129cb438ec3282451475c45017266c1f) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID177391264520250610172725.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SR00788DE ## ADs that name it (0) None. ## Approved models (4) - Billings Flying Service Inc CH-47D ([TCDS R0011DE](https://openairdocs.org/tcds/R0011DE)) - Billings Flying Service Inc. CH-47D ([TCDS R00115SE](https://openairdocs.org/tcds/R00115SE)) - Billings Flying Service, Inc. CH-47D ([TCDS R0015DE](https://openairdocs.org/tcds/R0015DE)) - Tandem Rotor LLC CH-47D ([TCDS R0014DE](https://openairdocs.org/tcds/R0014DE)) ## 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. SR00788DE Billings Flying Service Inc. 3655 A J Way Billings, MT 59106 * * * * See Approved Model List (AML) SR00788DE for approved aircraft models and applicable airworthiness regulations. 1. Operation must be in accordance with the BFS Rotorcraft Flight Manual Supplement listed on AML SR00788DE. 2. Maintenance must be in accordance with BFS Instructions for Continued Airworthiness, document BFS-202-101, Revision 0, dated March 23, 2015, or later FAA-accepted revision. 09/22/2014 07/14/2015 06/06/2025 for Manager, West Certification Branch 3 Installation of bubble window doors on left and right sides of the pilot compartment of CH-47D rotorcraft, in accordance with Billings Flying Service (BFS) modification drawing as listed on AML SR00788DE. SR00788DE 06/06/2025 3 SR00788DE 06/06/2025 Limitations and Conditions, continued: 3. A copy of this STC, AML, modification drawing, RFMS, and ICA must be provided to the aircraft owner/operator and be retained as part of the permanent records for modified aircraft. 4. Compliance with noise requirements has not been shown. Therefore, aircraft with this type design change installed are only eligible for agricultural operations and forest and wildlife conservation operations excepted by 14 CFR § 36.1(a)(4) and defined under § 137.3; and external cargo operations excepted by § 36.1(a)(4) and defined under § 133.1(b), provided that the aircraft's TCDS permits such special purpose operations. 5. The installer must determine whether this design change is compatible with previously approved modifications. 6. If the holder agrees to permit another person to use this certificate to alter a product, the holder must give the other person written evidence of that permission. END 3 3 Add Page ### SR00788DE_AML.pdf FEDERAL AVIATION ADMINISTRATION (FAA) APPROVED MODEL LIST (AML) SR00788DE FOR BILLINGS FLYING SERVICE, INC. INSTALLATION OF BUBBLE WINDOW DOORS ON LEFT AND RIGHT SIDES OF PILOT COMPARTMENT ISSUE DATE: April 22, 2017 Page 1 of 1 Item ROTORCRAFT MAKE **ROTORCRAFT MODEL** **ORIGINAL TC NUMBER** **CERTIFICATION** **BASIS FOR** **ALTERATION** **FAA APPROVED** **ROTORCRAFT FLIGHT** **MANUAL SUPPLEMENT** **FAA APPROVED** **MODIFICATION DRAWING** AML REV DATE Number Revision* Drawing Revision* 1 Billings Flying Service, Inc. CH-47D R0011DE 14 CFR Part 29 BFS-210-101 Original, approved 06/23/2015 BFS-003-002 D dated 04/15/2015 6/6/2025 2 Tandem Rotor, LLC CH-47D R0014DE 14 CFR Part 29 BFS-210-101 Original, approved 06/23/2015 BFS-003-002 D dated 04/15/2015 6/6/2025 3 Billings Flying Service, Inc. CH-47D R0015DE 14 CFR Part 29 BFS-210-101 Original, approved 06/23/2015 BFS-003-002 D dated 04/15/2015 6/6/2025 4 Billings Flying Service, Inc. CH-47D R00115SE 14 CFR Part 29 BFS-210-101 Original, approved 06/23/2015 BFS-003-002 D dated 04/15/2015 6/6/2025 * Or later FAA Approved Revision FAA Approved: for Manager, West Certification Branch AMENDED: May 17, 2018, June 6, 2025 REISSUED: ## Every issue (2) - June 6, 2025: Amended, Current. [certificate](https://openairdocs.org/files/sha256/51/7e/517e315585b2ddc263f10fdc7d5a95156b6484030553865d2d8a05b7e1c56cbe), [SR00788DE_AML.pdf](https://openairdocs.org/files/sha256/30/89/3089359d74ac02b6129f691fa33bd2cb129cb438ec3282451475c45017266c1f) - July 14, 2015: Issued, Historical. [certificate](https://openairdocs.org/files/sha256/78/cc/78ccf7af644da590e6069496d8bd69959a4e2a939dc62ccedc6eeb07aaae14cc) --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.