# Proposed AD FAA-2015-2959: The Boeing Company Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2016-07-25
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: July 24, 2015, 80 FR 43972
- Comments due: September 8, 2015
- Became: [AD 2016-07-25](https://openairdocs.org/ad/2016-07-25)
- Docket: FAA-2015-2959 (https://www.regulations.gov/docket/FAA-2015-2959, where comments are filed)
- Project: 2015-NM-008-AD
- FR document: 2015-18151
- Official PDF: https://openairdocs.org/files/sha256/45/f8/45f8d679fa331676a9b81dee85d7c82ca9ea873b89e169a12f2c6c306b1aaa3a (from https://www.govinfo.gov/content/pkg/FR-2015-07-24/pdf/2015-18151.pdf)
- Federal Register: https://www.federalregister.gov/documents/2015/07/24/2015-18151/airworthiness-directives-the-boeing-company-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/1F903E2D5E13C44786257E8C0046C08E.0001
- Page: https://openairdocs.org/proposed/FAA-2015-2959

## Summary

We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-8 airplanes. This proposed AD was prompted by reports indicating that the ram air turbine (RAT) assembly may fail to operate if deployed at low airspeeds. This proposed AD would require replacing either the RAT pump and control module assembly or the entire RAT assembly. We are proposing this AD to prevent failure of the RAT assembly to operate at low air speeds. The volume fuse on the RAT assembly may be activated in-flight before the RAT is deployed. This may lead to improper pump hydraulic pressure offloading when the RAT is needed. Failure of the RAT to operate in an all engine out event would result in loss of control of the airplane.

## Notices in this docket

- Jul 24, 2015: Notice of proposed rulemaking (NPRM). (first notice), FR document 2015-18151, comments due Sep 8, 2015 (https://www.federalregister.gov/documents/2015/07/24/2015-18151/airworthiness-directives-the-boeing-company-airplanes)

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