# Proposed AD FAA-2009-0995: Bombardier Model CL-600-2C10 (Regional Jet Series 700 & 701) Airplanes, Model CL-600-2D15 (Regional Jet Series 705) Airplanes, and Model CL-600-2D24 (Regional Jet Series 900) Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2010-13-05
- Products: Bombardier
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: October 28, 2009, 74 FR 55493
- Comments due: December 14, 2009
- Became: [AD 2010-13-05](https://openairdocs.org/ad/2010-13-05)
- Docket: FAA-2009-0995 (https://www.regulations.gov/docket/FAA-2009-0995, where comments are filed)
- Project: 2009-NM-123-AD
- FR document: E9-25866
- Official PDF: https://openairdocs.org/files/sha256/93/2e/932e7476e848702ba8a23166c5280a46236c6ab16f495fa3b7ec1913acf1dda9 (from https://www.govinfo.gov/content/pkg/FR-2009-10-28/pdf/E9-25866.pdf)
- Federal Register: https://www.federalregister.gov/documents/2009/10/28/E9-25866/airworthiness-directives-bombardier-model-cl-600-2c10-regional-jet-series-700-and-701-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/2DF74002669152F78625765D0047BB78.0001
- Page: https://openairdocs.org/proposed/FAA-2009-0995

## 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:

Investigation into a landing gear retraction problem on a production test flight revealed that, during aircraft pressurization and depressurization cycles, the pressure floor in the main landing gear bay deflects to a small extent. This causes relative misalignment between the [alternate-extension system] AES bypass valve, the downlock assist valve and the summing lever which, in turn, can result in damage to and potential failure of the respective clevis attached to one or both of the valves. Such a clevis failure could remain dormant and, in the subsequent event that use of the AES was required, full landing gear extension may not be achievable.

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

## Notices in this docket

- Oct 28, 2009: Notice of proposed rulemaking (NPRM). (first notice), FR document E9-25866, comments due Dec 14, 2009 (https://www.federalregister.gov/documents/2009/10/28/E9-25866/airworthiness-directives-bombardier-model-cl-600-2c10-regional-jet-series-700-and-701-airplanes)

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