# Proposed AD FAA-2026-13809: Diamond Aircraft Industries GmbH Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Comments due Dec 28
- Products: Diamond Aircraft Industries DA 50 C
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: November 12, 2026, 91 FR 72819
- Comments due: December 28, 2026
- Docket: FAA-2026-13809 (https://www.regulations.gov/docket/FAA-2026-13809, where comments are filed)
- Project: MCAI-2026-00761-A
- FR document: 2026-23068
- Official PDF: https://openairdocs.org/files/sha256/65/4c/654cba4250a50496ab4b0059403c570c71461dcfe269d85f3336473c1da8c0e9 (from https://www.govinfo.gov/content/pkg/FR-2026-11-12/pdf/2026-23068.pdf)
- Federal Register: https://www.federalregister.gov/documents/2026/11/12/2026-23068/airworthiness-directives-diamond-aircraft-industries-gmbh-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FR-ADNPRM-2026-23068-00000000000.0001
- Page: https://openairdocs.org/proposed/FAA-2026-13809

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for all Diamond Aircraft Industries GmbH (DAI) Model DA 50 C airplanes. This proposed AD was prompted by reports of flap actuator failures. This proposed AD would require inspecting for displacement of the black slide grommet and inspecting the rod end bearing for a tight fit of the flap actuator. This proposed AD would also require modification of the flap actuator followed by repetitive inspections for a broken actuator torque seal on the jam nuts at the attachment of the rod end bearing of the flap actuator with applicable corrective action. This proposed AD would also prohibit the installation of unmodified flap actuators on any airplane. The FAA is proposing this AD to address the unsafe condition on these products.

## Service documents this proposal cites (1) (OpenAirDocs)

Manufacturers' service documents named in its text, read by OpenAirDocs, so check each against the text.

- [Diamond Aircraft MSB 50-016](https://openairdocs.org/service-documents/diamond/sb-50-016.md), dated Jul 9, 2026. Cited as "DAI MSB 50-016, dated July 9, 2026"

## Docket FAA-2026-13809 (0)

The documents in the docket on regulations.gov (https://www.regulations.gov/docket/FAA-2026-13809), oldest first. Comments are on regulations.gov.

OpenAirDocs hasn't listed its documents yet.

## Notices in this docket

- Nov 12, 2026: Notice of proposed rulemaking (NPRM). (first notice), FR document 2026-23068, comments due Dec 28, 2026 (https://www.federalregister.gov/documents/2026/11/12/2026-23068/airworthiness-directives-diamond-aircraft-industries-gmbh-airplanes)

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