# Proposed AD FAA-2009-1223: Bombardier, Inc. Model DHC-8-400 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2010-12-06
- Products: Bombardier
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: December 30, 2009, 74 FR 69038
- Comments due: February 16, 2010
- Became: [AD 2010-12-06](https://openairdocs.org/ad/2010-12-06)
- Docket: FAA-2009-1223 (https://www.regulations.gov/docket/FAA-2009-1223, where comments are filed)
- Project: 2009-NM-114-AD
- FR document: E9-30905
- Official PDF: https://openairdocs.org/files/sha256/80/93/8093ccfc124cd1f27511d34aebafcc406a065d201b17d69a24d1828a17df1b10 (from https://www.govinfo.gov/content/pkg/FR-2009-12-30/pdf/E9-30905.pdf)
- Federal Register: https://www.federalregister.gov/documents/2009/12/30/E9-30905/airworthiness-directives-bombardier-inc-model-dhc-8-400-series-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/BA664789ED1F31898625769C004FD45B.0001
- Page: https://openairdocs.org/proposed/FAA-2009-1223

## Summary

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

During final Acceptance Test Procedure (ATP), a small oil leak was discovered on the Spoiler Unload Valve and Rudder Shutoff Valve bodies. Investigation revealed that a number of valves were manufactured with an incorrect wall thickness. This thin wall condition caused cracking, subsequent external weeping and pressure loss from the subject valves.

This condition, if not corrected, will cause a loss of hydraulic fluid and subsequent loss of spoiler and/or rudder control. * * * * *

The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

## Notices in this docket

- Dec 30, 2009: Notice of proposed rulemaking (NPRM). (first notice), FR document E9-30905, comments due Feb 16, 2010 (https://www.federalregister.gov/documents/2009/12/30/E9-30905/airworthiness-directives-bombardier-inc-model-dhc-8-400-series-airplanes)

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.