# Proposed AD FAA-2011-1093: The Boeing Company Model 757 Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2012-16-16
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: October 25, 2011, 76 FR 65991
- Comments due: December 9, 2011
- Became: [AD 2012-16-16](https://openairdocs.org/ad/2012-16-16)
- Docket: FAA-2011-1093 (https://www.regulations.gov/docket/FAA-2011-1093, where comments are filed)
- Project: 2010-NM-149-AD
- FR document: 2011-27484
- Official PDF: https://openairdocs.org/files/sha256/74/0e/740ef589e8af1e968b46c6cad4243ae9bd0d4d539c240dd624a8a3c59a0f8624 (from https://www.govinfo.gov/content/pkg/FR-2011-10-25/pdf/2011-27484.pdf)
- Federal Register: https://www.federalregister.gov/documents/2011/10/25/2011-27484/airworthiness-directives-the-boeing-company-model-757-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/AB5EC6E32190CB97862579350062AEE8.0001
- Page: https://openairdocs.org/proposed/FAA-2011-1093

## Summary

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD would require repetitive detailed inspections for discrepancies of the horizontal stabilizer ballscrew assembly; repetitive lubrication of the horizontal stabilizer trim control system; repetitive measurements for discrepancies of the ballscrew to ballnut freeplay; and corrective actions if necessary. This proposed AD was prompted by a report of extensive corrosion of the ballscrew of the drive mechanism of the horizontal stabilizer trim actuator. We are proposing this AD to prevent undetected failure of the primary and secondary load paths for the ballscrew in the horizontal stabilizer, which could lead to loss of control of the horizontal stabilizer and consequent loss of control of the airplane.

## Notices in this docket

- Oct 25, 2011: Notice of proposed rulemaking (NPRM). (first notice), FR document 2011-27484, comments due Dec 9, 2011 (https://www.federalregister.gov/documents/2011/10/25/2011-27484/airworthiness-directives-the-boeing-company-model-757-airplanes)

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