# Proposed AD 99-NE-50-AD: Rolls-Royce Ltd. Dart 511, 511-7E, 514- 7, 528, 528-7E, 529-7E, 532-7, 532-7L, 532-7N, 532-7P, 532-7R, 535-7R, 551-7R, and 552-7R Turboprop Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2000-12-18
- Action: Notice of proposed rulemaking (NPRM).
- Published: January 12, 2000, 65 FR 1840
- Comments due: March 13, 2000
- Became: [AD 2000-12-18](https://openairdocs.org/ad/2000-12-18)
- Docket: 99-NE-50-AD
- FR document: 00-722
- Official PDF: https://openairdocs.org/files/sha256/c9/78/c9786d677ea8fb24a0fe2bcb4443766a696633af27490392cbec17f93b16e03d (from https://www.govinfo.gov/content/pkg/FR-2000-01-12/pdf/00-722.pdf)
- Federal Register: https://www.federalregister.gov/documents/2000/01/12/00-722/airworthiness-directives-rolls-royce-ltd-dart-511-511-7e-514--7-528-528-7e-529-7e-532-7-532-7l
- Page: https://openairdocs.org/proposed/99-NE-50-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Rolls-Royce Ltd. (R-R) Dart 511, 511-7E, 514-7, 528, 528-7E, 529-7E, 532-7, 532-7L, 532-7N, 532-7P, 532- 7R, 535-7R, 551-7R, and 552-7R turboprop engines. This proposal would require the installation of a feathering probe and a steel retaining ring in the reduction gear housing (RGH), and replacement of a transfer bobbin installed in the torquemeter. This proposal is prompted by two reports of the failure of a propeller to feather following the failure of the RGH annulus gear, which resulted in the propeller overspeeding and the release of a propeller blade, causing damage to the airplane. The actions specified by the proposed AD are intended to prevent a propeller from overspeeding and the release of a propeller blade after a failure of the RGH annulus gear, which could result in damage to an adjacent engine or to the airplane.

## Notices in this docket

- Jan 12, 2000: Notice of proposed rulemaking (NPRM). (first notice), FR document 00-722, comments due Mar 13, 2000 (https://www.federalregister.gov/documents/2000/01/12/00-722/airworthiness-directives-rolls-royce-ltd-dart-511-511-7e-514--7-528-528-7e-529-7e-532-7-532-7l)

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