# STC SR09947AC - Type: Supplemental type certificate - Status: Current, Issued - Holder: Ahlers Aerospace Inc., United States - Description: Replacement of the original N2 tachometer with a corresponding Ahlers tachometer - Applied: December 6, 2018 - Status date: September 5, 2024 - Product: Aircraft, Rotorcraft - Certification basis: Part 27 - Data sheets: [TCDS H88EU](https://openairdocs.org/tcds/H88EU) - Certificate PDF: https://openairdocs.org/files/sha256/f4/09/f409f7fb24f7c822a2806cce7a52e4ef61f25edfd24bf8ebc60de7bc7317853e - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID157986188520240911183559.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SR09947AC ## ADs that name it (0) None. ## Approved models (3) - Airbus Helicopters Deutschland GmbH (AHD) EC135P1 ([TCDS H88EU](https://openairdocs.org/tcds/H88EU)) - Airbus Helicopters Deutschland GmbH (AHD) EC135P2 ([TCDS H88EU](https://openairdocs.org/tcds/H88EU)) - Airbus Helicopters Deutschland GmbH (AHD) EC135P2+ ([TCDS H88EU](https://openairdocs.org/tcds/H88EU)) ## 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 (03/21) SUPERSEDES PREVIOUS EDITION United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number: Part of . SR09947AC Ahlers Aerospace, Inc. 3621 Raider Drive Hurst, TX 76053 27 the Federal Aviation Regulations. H88EU Compliance & Airworthiness Division Aircraft Certification Service December 6, 2018 September 5 , 2024 for Paul Nguyen Manager, Central Certification Branch Page 1 of 3 Airbus Helicopter Model: EC135P1, EC135P2, EC135P2+ Description of Type Design Change: Replacement of the original N2 tachometer with a corresponding Ahlers tachometer in accordance with Ahlers Aerospace Inc. Master Drawing List E99-346, Revision F, dated May 17, 2024, or later FAA approved revision. The installer must determine whether this design change is compatible with previously approved modifications. 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. Deutschland GmbH (AHD) FAA Form 8110-2 (03/21) SUPERSEDES PREVIOUS EDITION United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number: SR09947AC Page 2 of _3 FAA Form 8110-2 (3/21) United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: Page 3 of 3 SR09947AC Limitations and Conditions (continued) Instructions for Continued Airworthiness (ICA), Document E99-348, Revision C, dated January 5, 2024, or later FAA approved revision, must be made available to the operator at the time of installation. Certification Basis: Based on 14 CFR ยงยง 21.115 and 21.101, and FAA Order 8110.48, the certification basis for the Airbus EC135P1/P2/P2+ models is as follows: a. The type certification basis for Airbus EC135 model helicopters is shown on TCDS H88EU for parts not changed or not affected by the change. b. The certification basis for parts changed or affected by the change since the reference date of application, December 6, 2018, is based upon part 27 as amended by Amendment 31. The certification basis for this modification was determined to be: Regulations at the amendment level in TCDS H88EU 27.301; 27.303; 27.305; 27.307; 27.561 (b)(3)(i)(ii)(iii)(iv); 27.601; 7.603; 605(a); 27.613 (a), (b)(1) (2), (c); 27.771; 27.1301; 27.1305 (k)(1)(2)(3); 27.1309 (a); 27.1317; 27.1321 (a), (b), (c); 27.1357 (a), 27.1381 (a), (b)(1)(2); 27.1501; 27.1529; 27.1543 (a), (b); 27.1549 Regulations at amendment 27-46: 27.610 (b), (d) Regulations at amendment 27-50: 27.773 (a)(1), (b) (1' ## Every issue (1) - September 5, 2024: Issued, Current. [certificate](https://openairdocs.org/files/sha256/f4/09/f409f7fb24f7c822a2806cce7a52e4ef61f25edfd24bf8ebc60de7bc7317853e) --- 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.