# Federal Register #2026-22310

FAA Airworthiness Directive for Diamond DA 40, DA 40 F, and DA 40 NG Aircraft

**Buyer:** U.S. Department of Transportation, Federal Aviation Administration (FAA)
**Posted:** November 02, 2026
**Identifier:** 2026-22310

The Federal Aviation Administration issued an airworthiness directive addressing passenger-door safety on Diamond aircraft; this is a regulatory safety action, not a procurement solicitation.
- **Government buyer:** U.S. Department of Transportation, Federal Aviation Administration (FAA).
- **OEM:** **Diamond Aircraft Industries Inc.**, manufacturer of the covered DA 40, DA 40 F, and DA 40 NG airplanes and publisher of the referenced service information.
- **Affected fleet:** An estimated 987 U.S.-registered airplanes.
- **Required compliance actions:** Revise the applicable airplane flight manual; inspect passenger-door latching, safety-hook mechanisms, and specified components; measure door-handle actuation force; and install placards.
- **Corrective actions:** Replace gas springs and, when inspections or measurements require, replace the hook assembly, retaining block, door guide blocks, or door sealant. The directive references Diamond Aircraft service bulletin MSB 40-103/MSB F4-042/MSB D4-114/MSB 40NG-084 and model-specific flight-manual revisions.
- **Timing:** Initial actions are due within 100 hours time-in-service or 100 days after the directive takes effect, whichever comes first. Certain gas spring replacements are due within 12 months; applicable repeat inspections are required every 100 hours time-in-service until replacement.
- **Procurement scope:** No products, purchase quantities, or contract value are specified.

### Description

The FAA is adopting a new airworthiness directive for all Diamond Aircraft Industries Inc. Model DA 40, DA 40 F, and DA 40 NG airplanes following reports of passenger door separation during flight. The directive requires revising airplane flight manuals, inspecting door latching and safety-hook mechanisms and specified components, measuring passenger door handle actuation force, and installing placards. It also requires replacing the gas spring and, when necessary, replacing the hook assembly, retaining block, door guide blocks, and door sealant. The rule is effective December 7, 2026.

[View original listing](https://www.federalregister.gov/documents/2026/11/02/2026-22310/airworthiness-directives-diamond-aircraft-industries-inc-airplanes)