# STC SA2991SO - Type: Supplemental type certificate - Status: Current, Reissued - Holder: Purolator Facet, Inc, United States - Description: Installation of a replacement coalescer filter, P/N 21D10 or 21D10-1, or 21BC125.. - Applied: May 3, 1991 - Status date: October 19, 2017 - Product: Aircraft, Large Multi-Engine - Certification basis: Part 21 - Data sheets: [TCDS A6WE](https://openairdocs.org/tcds/A6WE) - Certificate PDF: https://openairdocs.org/files/sha256/f2/56/f256a03859fe88b066bda16259e1615543870bf49aaf2e6687ce9f68a0225ba8 - Approved model list and other attachments: [SA2991SO_AML.pdf](https://openairdocs.org/files/sha256/55/3e/553e4bcb5b922e451a78bf234cdcf845b8f4231d99d6b8a5a413cefe6012d6ef) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/382648BB4064DF22862581F5004AFC0E.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA2991SO ## ADs that name it (0) None. ## Approved models (24) - McDonnell Douglas Corporation DC-9-11 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-12 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-13 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-14 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-15 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-15F ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-21 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-31 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-32 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-32 (VC-9C) ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-32F ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-32F (C-9A) ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-32F (C-9B) ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-33F ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-34 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-34F ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-41 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-51 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-81 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-82 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-83 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation DC-9-87 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation MD-88 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) - McDonnell Douglas Corporation MD-90-30 ([TCDS A6WE](https://openairdocs.org/tcds/A6WE)) ## 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. FAA Form 8110-2 (5/14) Page 1 of Part of the Signature Title SA2991SO Purolator Facet, Inc. 8439 Triad Drive Greensboro, NC 27409 25 Federal Aviation Regulations. * See attached FAA Approved Model List (AML) No. SA2991SO for list of approved airplane models and applicable airworthiness regulations 2 A6WE Installation of Keddeg Company P/N 21D10 or P/N 21D10-1 or P/N 21BC125 Coalescer Assembly. See attached AML No. SA2991SO for required data. Compatibility of this design change with previously approved modifications must be determined by the installer. 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. October 10, 1996, October 19, 2017 March 18, 1992; July 9, 1992; July 31, 2002 May 3, 1991 July 31, 1991 Tina Miller Manager, Program Management Section Wichita ACO Branch FAA Form 8110-2 (5/14) Page 2 of To (Name and address of transferee) From (Name and address of grantor) 2 SA2991SO ### SA2991SO_AML.pdf FAA Approved Model List (AML) No. SA2991SO Installation of Keddeg Company P/N 21D10 or P/N 21D10-1 or P/N 21BC125 Coalescer Assembly Original Issue Date: July 31, 1991 1 of 1 **ITEM AIRCRAFT MAKE AIRCRAFT MODEL** **ORIGINAL TYPE** **CERTIFICATE NUMBER** **CERTIFICATION** **BASIS FOR** **ALTERATION** **INSTALLATION** **INSTRUCTIONS AFMS** **NUMBER / DATE AML** AMENDMENT DATE DWG. NUMBER REVISION DATE 1 McDonnell-Douglas DC-9, MD-80, MD-81, MD-82, MD-83, MD-87, MD-88, MD-90 A6WE FAR 25 CD-21D10-1 CD-21D10 KDL- 21BC125 Rev –* 04/15/91 Rev A* 1/07/92 Rev –* 04/25/02 N/A 7/31/02 *Or later FAA Approved revision Note: AML added to STC SA2991SO on 7/31/02 FAA Approved: __Original signed by Tina Miller _________________ Tina Miller Manager, Program Management Section Wichita ACO Branch Reissued: 10/19/17 ## Every issue (3) - October 19, 2017: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/f2/56/f256a03859fe88b066bda16259e1615543870bf49aaf2e6687ce9f68a0225ba8), [SA2991SO_AML.pdf](https://openairdocs.org/files/sha256/55/3e/553e4bcb5b922e451a78bf234cdcf845b8f4231d99d6b8a5a413cefe6012d6ef) - July 31, 2002: Amended, Historical. [certificate](https://openairdocs.org/files/sha256/af/28/af28a5f5d658dfc7c9200033fa66af6d323ad95ecd786c2dec0722b9fe0894eb), [SA2991SO_AML.pdf](https://openairdocs.org/files/sha256/e0/ee/e0eeadaa8cdd52b0d7ad0fd8310253782c52ab8f225c69453cfa26ad6b6f8f5f) - July 21, 2002: Amended, Historical. [certificate](https://openairdocs.org/files/sha256/e0/ee/e0eeadaa8cdd52b0d7ad0fd8310253782c52ab8f225c69453cfa26ad6b6f8f5f), [SA2991SO .pdf](https://openairdocs.org/files/sha256/af/28/af28a5f5d658dfc7c9200033fa66af6d323ad95ecd786c2dec0722b9fe0894eb) --- 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.