# Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes
> **Rule** · Final rule. · Published 2026-03-04 · Effective 2026-04-08 · 91 FR 10510
## Document
- **Document number:** 2026-04278
- **Category:** airworthiness
- **Manufacturer:** Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 91 FR 10510
- **Publication date:** 2026-03-04
- **Effective date:** 2026-04-08
- **FAA docket:** Docket No. FAA-2025-2545
## Abstract

The FAA is adopting a new airworthiness directive (AD) for certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500- 1A11 airplanes. This AD was prompted by reports of certain fuel transfer float valves failing in the closed position, preventing normal fuel transfer between the center and wing fuel tanks. This AD requires replacing the existing fuel transfer float valves on airplanes approved for extended-range twin-engine operation performance standards (ETOPS). The FAA is issuing this AD to address the unsafe condition on these products.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2026/03/04/2026-04278/airworthiness-directives-airbus-canada-limited-partnership-type-certificate-previously-held-by-c)
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