# Proposed AD 2000-NM-98-AD: Boeing Model 747 Series Airplanes Equipped With Pratt & Whitney (PW) JT9D-7Q and JT9D-7Q3 Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2000-21-06
- Action: Notice of proposed rulemaking (NPRM).
- Published: May 3, 2000, 65 FR 25696
- Comments due: June 19, 2000
- Became: [AD 2000-21-06](https://openairdocs.org/ad/2000-21-06)
- Docket: 2000-NM-98-AD
- FR document: 00-11064
- Official PDF: https://openairdocs.org/files/sha256/37/27/372709637e8246bc4e1e05c71992ecb650b6d0884b3cac22dab97f9560d52adf (from https://www.govinfo.gov/content/pkg/FR-2000-05-03/pdf/00-11064.pdf)
- Federal Register: https://www.federalregister.gov/documents/2000/05/03/00-11064/airworthiness-directives-boeing-model-747-series-airplanes-equipped-with-pratt-and-whitney-pw
- Page: https://openairdocs.org/proposed/2000-NM-98-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This proposal would require a detailed visual inspection to detect evidence of wear or contact between the precooler support fitting and link assembly; and rework and reidentification of the fitting. This proposal is prompted by a report of rupturing of a diffuser case on a PW JT9D-7Q engine due to cracking in the outer pressure wall in the rear skirt area. The actions specified by the proposed AD are intended to prevent contact between the precooler support link and the precooler support fitting, which could contribute to an uncontained failure of the diffuser case and damage to the airplane.

## Notices in this docket

- May 3, 2000: Notice of proposed rulemaking (NPRM). (first notice), FR document 00-11064, comments due Jun 19, 2000 (https://www.federalregister.gov/documents/2000/05/03/00-11064/airworthiness-directives-boeing-model-747-series-airplanes-equipped-with-pratt-and-whitney-pw)

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