# Airworthiness Directives; Rolls-Royce Spey 555-15, -15H, -15N, and -15P Turbofan Engines
> **Rule** · Final rule. · Published 2000-11-15 · Effective 2000-12-20 · 65 FR 68875
## Document
- **Document number:** 00-28960
- **Category:** airworthiness
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 65 FR 68875
- **Publication date:** 2000-11-15
- **Effective date:** 2000-12-20
- **FAA docket:** Docket No. 2000-NE-03-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to Rolls-Royce (RR) plc. Spey 555-15, -15H, -15N, and -15P turbofan engines, that requires modification of the low pressure (LP) turbine stage 2 nozzle guide vane (NGV) support ring seal assembly. This amendment is prompted by two instances of disk drive arm damage. In both cases, heavy damage to the stage 1 LP turbine-to-stage 2 LP turbine disk drive arm occurred as a result of an out-of-balance condition following the failure of a stage 2 LP turbine blade. The actions specified by this AD are intended to prevent damage to the disk drive arm which could result in loss of stage 1 LP turbine-to-stage 2 LP turbine disk drive, a turbine overspeed condition, and possible uncontained disk failure and damage to the airplane.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2000/11/15/00-28960/airworthiness-directives-rolls-royce-spey-555-15--15h--15n-and--15p-turbofan-engines)
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