# Proposed AD FAA-2009-0134: Saab AB, Saab Aerosystems Model SAAB 340A (SAAB/SF340A) and SAAB 340B Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2009-23-07
- Products: SAAB
- Product type: Aircraft
- Action: Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.
- Published: August 12, 2009, 74 FR 40527
- Comments due: September 8, 2009
- Became: [AD 2009-23-07](https://openairdocs.org/ad/2009-23-07)
- Docket: FAA-2009-0134 (https://www.regulations.gov/docket/FAA-2009-0134, where comments are filed)
- Project: 2008-NM-162-AD
- FR document: E9-19261
- Official PDF: https://openairdocs.org/files/sha256/82/2e/822e8916064b0dffcd81503248adae111e6cfd02ab2bf448d5a93c699ea49187 (from https://www.govinfo.gov/content/pkg/FR-2009-08-12/pdf/E9-19261.pdf)
- Federal Register: https://www.federalregister.gov/documents/2009/08/12/E9-19261/airworthiness-directives-saab-ab-saab-aerosystems-model-saab-340a-saabsf340a-and-saab-340b-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A5BA2F4A5253CE9A86257610005137BD.0001
- Page: https://openairdocs.org/proposed/FAA-2009-0134

## Summary

We are revising an earlier NPRM for the products listed above. This action revises the earlier NPRM by expanding the scope. 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 2008, two cases of main hydraulic accumulator failure were reported, one of which was caused by corrosion. Investigation has shown that a severe failure can occur to any of the four hydraulic accumulators which are installed in the hydraulic compartment. Either one of the two end parts on the accumulator may depart from the pressure vessel due to corrosion. This condition, if not corrected, is likely to degrade the functionality of the hydraulic system, possibly resulting in degradation or total loss of control of the landing gear, flap actuation and brakes. A severe failure during flight may evenresult in debris penetrating and exiting the fuselage outer skin. When such a failure occurs while the aeroplane is on the ground, as in the two reported cases, this may cause severe damage to the fuselage and result in injuries to persons nearby.

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

## Notices in this docket

- Feb 18, 2009: Notice of proposed rulemaking (NPRM). (first notice), FR document E9-3398, comments due Mar 20, 2009 (https://www.federalregister.gov/documents/2009/02/18/E9-3398/airworthiness-directives-saab-ab-saab-aerosystems-model-saab-340a-saabsf340a-and-saab-340b-airplanes)
- Aug 12, 2009: Supplemental notice of proposed rulemaking (NPRM); reopening of comment period., FR document E9-19261, comments due Sep 8, 2009 (https://www.federalregister.gov/documents/2009/08/12/E9-19261/airworthiness-directives-saab-ab-saab-aerosystems-model-saab-340a-saabsf340a-and-saab-340b-airplanes)

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