# Federal Register #FAA-2026-13809

Proposed FAA airworthiness directive for Diamond DA 50 C flap actuators

**Buyer:** Federal Aviation Administration, U.S. Department of Transportation
**Posted:** November 12, 2026
**Respond By:** December 28, 2026
**Identifier:** FAA-2026-13809

The FAA proposes an airworthiness directive addressing flap actuator safety on Diamond Aircraft Industries GmbH Model DA 50 C airplanes.
- **Government buyer / issuing agency:** U.S. Department of Transportation, Federal Aviation Administration (FAA); no specific office is identified.
- **OEM:** **Diamond Aircraft Industries GmbH (DAI)**, manufacturer of the affected aircraft and actuator.
- **Scope:** Applies to all Model DA 50 C airplanes; the FAA estimates 30 U.S.-registered airplanes would be affected.
- **Proposed safety actions:** Inspect the flap actuator’s black slide grommet and rod-end-bearing fit, modify the actuator, and conduct repetitive inspections for broken actuator torque seals, with corrective action as needed. Installing an unmodified actuator would be prohibited.
  - Referenced compliance documents: DAI Work Instruction WI-MSB 50-016, Revision 0, and DAI Mandatory Service Bulletin DAI MSB 50-016.
- **Other proposed change in the notice:** Adjust Jet Route J-21 near Laredo, Texas, to remove an unnecessary turn.
- **Procurement status:** This is a proposed safety rule, not a purchase opportunity; no products or services, purchase quantities, or part numbers are specified.

### Description

The FAA proposes a new airworthiness directive for all Diamond Aircraft Industries GmbH Model DA 50 C airplanes, prompted by reports of flap actuator failures. The proposed requirements include inspecting the flap actuator for displacement of the black slide grommet and a tight rod-end-bearing fit, modifying the actuator, and conducting repetitive inspections with applicable corrective action. Installation of unmodified flap actuators would be prohibited. Comments are due December 28, 2026.

[View original listing](https://www.federalregister.gov/documents/2026/11/12/2026-23068/airworthiness-directives-diamond-aircraft-industries-gmbh-airplanes)