# Proposed AD FAA-2010-0803: Airbus Model A310 Series Airplanes; and Model A300 B4-600, A300 B4-600R, A300 F4-600R Series Airplanes, and Model A300 C4-605R Variant F Airplanes (Collectively Called A300-600 Series Airplanes)

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2011-08-05
- Products: Airbus
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: August 23, 2010, 75 FR 51698
- Comments due: October 7, 2010
- Became: [AD 2011-08-05](https://openairdocs.org/ad/2011-08-05)
- Docket: FAA-2010-0803 (https://www.regulations.gov/docket/FAA-2010-0803, where comments are filed)
- Project: 2010-NM-124-AD
- FR document: 2010-20854
- Official PDF: https://openairdocs.org/files/sha256/23/cf/23cf6b1e9683f035bac1a62c94dc66c377bca780417124076aa6f4c70e44ccdc (from https://www.govinfo.gov/content/pkg/FR-2010-08-23/pdf/2010-20854.pdf)
- Federal Register: https://www.federalregister.gov/documents/2010/08/23/2010-20854/airworthiness-directives-airbus-model-a310-series-airplanes-and-model-a300-b4-600-a300-b4-600r-a300
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/BFAE9C891414490C86257788006B02DD.0001
- Page: https://openairdocs.org/proposed/FAA-2010-0803

## 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: The ball screw nut assemblies of the first 70 Trimmable Horizontal Stabilizer Actuators (THSA) manufactured by Goodrich were fitted with an upper attachment gimbal having a thickness of 58 mm (2.28 in), which is different from the design of the final production standard. The gimbal installed on the subsequent THSAs (final production standard) is more robust, having a thickness of 70mm (2.76 in). During the fatigue life demonstration of the THSA upper attachment primary load path elements, only a gimbal having a thickness of 70mm (2.76 in) was used. Thereafter, no additional justification work to demonstrate the robustness of the upper attachmentfitted with a gimbal of 58 mm was accomplished. In case of failure of this gimbal, the THSA upper attachment primary load path would be lost and the THSA upper attachment secondary load path would engage. Because the upper attachment secondary load path will only withstand the loads for a limited period of time, the condition where it would be engaged and not detected could lead to failure of the secondary load path, which would likely result in loss of control of the aeroplane. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

## Notices in this docket

- Aug 23, 2010: Notice of proposed rulemaking (NPRM). (first notice), FR document 2010-20854, comments due Oct 7, 2010 (https://www.federalregister.gov/documents/2010/08/23/2010-20854/airworthiness-directives-airbus-model-a310-series-airplanes-and-model-a300-b4-600-a300-b4-600r-a300)

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