# STC SR11321DS

- Type: Supplemental type certificate
- Status: Current, Amended
- Holder: Airbus Helicopters Inc., United States
- Description: Installation of a Technisonic TDFM-9300 Multi-band FM Transceiver
- Applied: February 19, 2019
- Status date: May 19, 2026
- Product: Aircraft, Rotorcraft
- Certification basis: Part 27
- Data sheets: [TCDS H9EU](https://openairdocs.org/tcds/H9EU)
- Certificate PDF: https://openairdocs.org/files/sha256/9b/79/9b795bd9761d2bf35b12a873900058a579b912ed87087072ccf1b075df29d5d5
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID148758215220260520154011.0001
- DRS record last changed: May 20, 2026
- Page: https://openairdocs.org/stc/SR11321DS

## ADs that name it (0)

None.

## Approved models (1)

- Airbus Helicopters AS350B3 ([TCDS H9EU](https://openairdocs.org/tcds/H9EU))

## 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.

SR11321DS Airbus Helicopters, Inc.

2701 N. Forum Drive Grand Prairie, TX 75052 27 Code of Federal Regulations H9EU Airbus Helicopters AS350B3

1. This STC is applicable to all serial numbers for this Make/Model.

2. Additional limitations may be detailed in the Rotorcraft Flight Manual Supplement.

---See continuation sheet 3 2/19/19 7/31/20 5/19/26 Michael J. Gardiner, ODA-700097-SW Alternate ODA Lead administrator 3 Installation of a Technisonic TDFM-9300 Multi-band FM Transceiver in accordance with Airbus Helicopters, Inc. Master Drawing List 350A82-1909 Rev. B dated 06/23/2020 or later ODA approved revision.

SR11321DS 05/19/26 3

SR11321DS 05/19/26 Description of Type Design Change (continued from sheet 1):

For Configuration 350A82-1670-01, Rotorcraft Flight Manual Supplement 350FMS-552 Rev.

IR dated 07/27/2020 or later ODA approved revision and Instructions for Continued Airworthiness 350MMS-053 Rev. IR dated 07/02/2020 or later ODA or AED accepted revision are required.

For Configuration 350A82-1670-02, Rotorcraft Flight Manual Supplement 350FMS-552 Rev. A dated 5/19/2026 or later ODA approved revision and Instructions for Continued Airworthiness 350MMS-053 Rev. B dated 5/19/2026 or later ODA or AED accepted revision are required.

Certification Basis Based on 14 CFR §§ 21.115 and 21.101 and the FAA policy for significant changes in FAA Order 8110.48A, the certification basis is the same as TCDS H9EU, Rev 23, 11/18/2014, with the following exception:

14 CFR § 27.173 at Amendment 27-44 14 CFR § 27.175 at Amendment 27-44 14 CFR § 27.177 at Amendment 27-44 14 CFR § 27.773 at Amendment 27-50

Limitations and Conditions (continued from sheet 1):

3. The installer must determine whether this design change is compatible with previously approved modifications.

4. If the holder agrees to permit another person to use this certificate to alter the product, the holder must give the other person written evidence of that permission.

5. Installation of this STC reduces VNE power-off by 10 knots, with a minimum of 65 knots.

6. If an EO/IR sensor turret is installed forward of the TDFM antennas, then the following also applies: reduce VNE power-on by 10 knots, with a minimum of 65 knots.

## Every issue (2)

- May 19, 2026: Amended, Current. [certificate](https://openairdocs.org/files/sha256/9b/79/9b795bd9761d2bf35b12a873900058a579b912ed87087072ccf1b075df29d5d5)
- July 31, 2020: Issued, Historical. [certificate](https://openairdocs.org/files/sha256/87/ad/87ad32788bb9d9ae707843cf0ee7bee345d2532d5d78376eca326da00ccb61cc)

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