# Proposed AD 99-NM-72-AD: Boeing Model 767 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2000-07-05
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 23, 1999, 64 FR 33437
- Comments due: August 9, 1999
- Became: [AD 2000-07-05](https://openairdocs.org/ad/2000-07-05)
- Docket: 99-NM-72-AD
- FR document: 99-15931
- Official PDF: https://openairdocs.org/files/sha256/87/a2/87a286dd1022c76eefc7b2bb02ca6bdc97bd6521adc1ce9bd814512a47782404 (from https://www.govinfo.gov/content/pkg/FR-1999-06-23/pdf/99-15931.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/06/23/99-15931/airworthiness-directives-boeing-model-767-series-airplanes
- Page: https://openairdocs.org/proposed/99-NM-72-AD

## Summary

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, that currently requires repetitive inspections to detect cracking or damage of the forward and aft lugs of the diagonal brace of the nacelle strut, and follow-on actions, if necessary. That AD also provides optional terminating action for the repetitive inspections. This proposal would require accomplishment of the previously optional terminating action. This proposal is prompted by a report that a fractured diagonal brace lug was found during a routine maintenance inspection. The actions specified by the proposed AD are intended to prevent cracking of the diagonal brace of the nacelle strut, which could result in failure of the diagonal brace, and consequent fatigue failure of a strut secondary load path and separation of the engine and strut.

## Notices in this docket

- Jun 23, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-15931, comments due Aug 9, 1999 (https://www.federalregister.gov/documents/1999/06/23/99-15931/airworthiness-directives-boeing-model-767-series-airplanes)

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