# STC SA11841BO - Type: Supplemental type certificate - Status: Current, Issued - Holder: T3 Tailwheel Suspension System, United States - Description: Installation of T3 Tailwheel Suspension System suspension - Applied: August 17, 2023 - Status date: November 22, 2024 - Product: Aircraft, Small Airplane - Data sheets: [TCDS 1A2](https://openairdocs.org/tcds/1A2), [TCDS A-799](https://openairdocs.org/tcds/A-799), [TCDS 5A5](https://openairdocs.org/tcds/5A5) - Certificate PDF: https://openairdocs.org/files/sha256/20/58/2058b118c573724d0ba25ad63c4a6e6fac0310058911216de5d8760d254b9d4d - Approved model list and other attachments: [SA11841BO_AML.pdf](https://openairdocs.org/files/sha256/7e/50/7e5062a2237c471b9ff8680031c1a01fc81f322dde8545700e1246e7c10e9171) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID132486125820260427174038.0001 - DRS record last changed: April 27, 2026 - Page: https://openairdocs.org/stc/SA11841BO ## ADs that name it (0) None. ## Approved models (22) - Piper Aircraft Inc. PA-18 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18-105 (Special) ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18-125 (Army L-21A) ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18-135 (Army L-21B) ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18-150 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18A ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18A-135 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18A-150 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18AS-125 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18AS-135 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18AS-150 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18S ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18S-105 (Special) ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18S-125 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18S-135 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-18S-150 ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-19 (Army L-18C) ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Piper Aircraft Inc. PA-19S ([TCDS 1A2](https://openairdocs.org/tcds/1A2)) - Regal Air Inc. 305A ([TCDS 5A5](https://openairdocs.org/tcds/5A5)) - Textron Aviation Inc. 170 ([TCDS A-799](https://openairdocs.org/tcds/A-799)) - Textron Aviation Inc. 170A ([TCDS A-799](https://openairdocs.org/tcds/A-799)) - Textron Aviation Inc. 170B ([TCDS A-799](https://openairdocs.org/tcds/A-799)) ## 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. United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number This certificate issued to: SA11841BO T3 Tailwheel Suspension Systems 88 Calderwood Lane Lincolnville, ME 04959 Part 3 the Civil Air Regulations. 1. The installer must determine whether this design change is compatible with previously approved modifications. (continued on Page 3 of 3) 8/17/23 11/22/24 for Christina Underwood Manager, East Certification Branch 3 Installation of T3 Tailwheel Suspension Systems suspension in accordance with Master Drawing List ABI-T3C170-DL, Initial Revision, dated October 31, 2023, or later FAA approved revision. This modification does not include an Airplane Flight Manual Supplement (AFM). United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number Date o transfer: SA11841BO 3 United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number SA11841BO Limitations and Conditions: 1. Maintenance must be in accordance with Instructions for Continued Airworthiness (ICA), Document Number ABI-DST3-ICA, Revision C, dated December 29, 2023, or later FAA accepted revision. 2. The ICA must be made available to the operator at the time of installation. 3. 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. Certification Basis: Based on 14 CFR § 21.115 and § 21.101, and the FAA policy for design changes that are identified as not significant in FAA Order 8110.48, the certification basis for the AML ABI-DST3-AML listed Make Model aircraft is as follows: a. The type certification for basis for parts not changed or affected by the change is shown on the applicable TCDS. b. The modification certification basis for parts changed or affected by the change since the date of application was determined to be: Regulations at the latest amendment 23-0 through 23-63: None Regulations at an intermediate amendment: None Regulations at the amendment level in the applicable TCDS: **CAR 3.143, 3.141, 3.145, 3.146, 3.171, 3.172, 3.173, 3.174, 3.244, 3.246, 3.250, 3.251,** 3.252, 3.291, 3.292, 3.293, 3.294, 3.295, 3.296, 3.301, 3.302, 3.303, 3.305, 3.306, 3.307, 3.351, 3.352, 3.353, 3.354, 3.355 -------------------------------------------------------END------------------------------------------------------- 3 3 ### SA11841BO_AML.pdf ABI-DST3-AML T3 Tailwheel Suspension System Approved Model List Approved Model List for the Installation of: T3 Tailwheel Suspension Systems Manufactured by ABI, LLC Doc No.: ABI-DST3-AML REV A October 31, 2023 ABI-DST3-AML T3 Tailwheel Suspension System Approved Model List Rev A Page 2 of 5 Table of Contents 1.0 Introduction … 4 2.0 Applicability … 4 3.0 Document Distribution … 4 4.0 Approved Model List … 5 ABI-DST3-AML T3 Tailwheel Suspension System Approved Model List Rev A Page 3 of 5 List of Revisions Revision Date Page Description - 1/13/2017 ALL Initial Release A 10/31/2023 5 Added Cessna 170 series and 305A to list ABI-DST3-AML T3 Tailwheel Suspension System Approved Model List Rev A Page 4 of 5 1.0 Introduction This document contains a list of approved models of aircraft that can be fitted with a double or dual coil- over shock variant of the ABI, LLC T3 Tailwheel Suspension System as a direct replacement for their current tail spring. Further, each aircraft model will also show a corresponding ABI, LLC part number for the appropriate T3 Tailwheel Suspension System that is approved for that application, and a reference to the ABI, LLC installation instruction document needed for that installation case. 2.0 Applicability he ABI, LLC T3 Tailwheel Suspension Systems listed in this document are applicable to the corresponding aircraft models shown in the table contained in Section 4.0. 3.0 Document Distribution Copies of this document will be distributed to all known purchasers of one of the T3 Tailwheel Suspension Systems listed within this document. Replacement copies and the latest revision of this document are available on the Airframes Alaska website or by using the following contact information below. Website: www.airframesalaska.com To request a paper or electronic copy to be sent to you please contact: Airframes Alaska 81 E. Commercial Drive Palmer, AK 99645 Phone: 907-331-4480 ABI-DST3-AML T3 Tailwheel Suspension System Approved Model List Rev A Page 5 of 5 4.0 Approved Model List Make: Model: Applicable ABI, LLC T3 Tailwheel Suspension Assembly and Installation Instructions: Piper PA-18, PA-18S, PA-18 105, PA-18S 105, PA-18A, PA-18 125, L-21A, PA-18S 125, PA-18AS 125, PA-18 135, L-21B, PA- 18A 135, PA-18S 135, PA-18AS 135, PA- 18 150, PA-18A 150, PA-18S 150, PA- 18AS 150, PA-19, L-18C, PA-19S Assembly: **ABI-51343** With accompanying installation instructions: ABI-51343-II Cessna (Textron Aviation, Inc.) Cessna (Regal Air, Inc.) 170, 170A, 170B 305A Assembly: **ABI-51525** With accompanying installation instructions: **ABI-51525-II** ## Every issue (1) - November 22, 2024: Issued, Current. [certificate](https://openairdocs.org/files/sha256/20/58/2058b118c573724d0ba25ad63c4a6e6fac0310058911216de5d8760d254b9d4d), [SA11841BO_AML.pdf](https://openairdocs.org/files/sha256/7e/50/7e5062a2237c471b9ff8680031c1a01fc81f322dde8545700e1246e7c10e9171) --- 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.