# STC ST12466CH - Type: Supplemental type certificate - Status: Current, Issued - Holder: STS Engineering Solutions, LLC, United States - Description: Installation of Seat Blocker Interior Reconfiguration - Applied: May 18, 2026 - Status date: August 28, 2026 - Product: Aircraft, Large Airplane - Certification basis: Part 25 - Data sheets: [TCDS A53EU](https://openairdocs.org/tcds/A53EU) - Certificate PDF: https://openairdocs.org/files/sha256/2d/05/2d05dd760207817e1d56e80cd6183c11aa28bed8468699caca00901eba17fb4a - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID171061619720260918152731.0001 - DRS record last changed: September 18, 2026 - Page: https://openairdocs.org/stc/ST12466CH ## ADs that name it (0) None. ## Approved models (2) - ATR – GIE Avions de Transport Régional ATR42-500 ([TCDS A53EU](https://openairdocs.org/tcds/A53EU)) - ATR – GIE Avions de Transport Régional ATR72-212A ([TCDS A53EU](https://openairdocs.org/tcds/A53EU)) ## 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: ST12466CH Part 25 of the Federal Aviation Regulations. Original Product Type Certificate Number: A53EU Make: ATR – GIE Avions de Transport Régional Model: ATR42-500, ATR72-212A Date of Application: May 18, 2026 Date Reissued: Date of Issuance: August 28, 2026 Date Amended: Brenda L. Litchfield ODA Administrator Title: Envoy Aerospace, LLC ODA-831240-CE STS Engineering Solutions, LLC 2000 NE Jensen Beach BLVD Jensen Beach, FL 34957 Installation of Seat Blocker Interior Reconfiguration in accordance with STS Engineering Solutions Master Data List, Doc. No. DL25117-01, Revision IR, dated August 26, 2026, or later FAA-approved revision. 1) This STC is applicable to all serial numbers for this Make-Model. 2) The installer must determine whether this design change is compatible with previously approved modifications. 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. Number: ST12466CH (Continuation Sheet) Number: ST12466CH Date of Issuance: August 28, 2026 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 8110.48A, the certification basis for the ATR – GIE Avions de Transport Régional ATR42-500 and ATR72-212A aircraft is as follows: a. The type certification basis for the ATR – GIE Avions de Transport Régional ATR42-500 and ATR72-212A aircraft is shown on TCDS A53EU for parts not changed or affected by the change. b. This certification basis for parts changed or affected by the change since the reference date of application is based upon 14 CFR Part 25 as amended by Amendment 25-54 as follows: Applicable regulations at the latest amendment 25-0 through 25-54 § 25.29(a)(b) § 25.601 § 25.603(a)(b)(c) § 25.605(a) § 25.789(a) § 25.791 § 25.803(a) § 25.812(a)(1)(b) § 25.813(a)(b)(c)(d) § 25.815 § 25.1301(a)(b)(c)(d) § 25.1411(a)(b)(d)(f)(g) § 25.1529 § 25.1541(a)(b) Applicable 14 CFR Part 25 regulations at other amendment levels § 25.853(a) [Amdt 25-116]. Applicable 14 CFR Part 26 regulations at the latest amendment 26-0 through 26-7 Based on 14 CFR § 21.101(g), applicable provisions of 14 CFR Part 26 are included in the certification basis. For any future 14 CFR Part 26 amendments, the holder of this STC must demonstrate compliance with the applicable sections. As of the latest amendment date of this STC, compliance has been found for the following regulations: 14 CFR § 26.11(c) [Amdt. No. 26-7]. This modification does not affect or create fatigue critical baseline structure. -----END----- ## Every issue (1) - August 28, 2026: Issued, Current. [certificate](https://openairdocs.org/files/sha256/2d/05/2d05dd760207817e1d56e80cd6183c11aa28bed8468699caca00901eba17fb4a) --- 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.