# Proposed AD FAA-2007-28352: Boeing Model 747-200B, 747-300, 747- 400, 747-400D, and 747-400F Series Airplanes Equipped With General Electric CF6-80C2 Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2007-26-07
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 5, 2007, 72 FR 31001
- Comments due: July 20, 2007
- Became: [AD 2007-26-07](https://openairdocs.org/ad/2007-26-07)
- Docket: FAA-2007-28352 (https://www.regulations.gov/docket/FAA-2007-28352, where comments are filed)
- Project: 2007-NM-037-AD
- FR document: E7-10757
- Official PDF: https://openairdocs.org/files/sha256/30/09/300994d9940d627b42fc2a617a005963ac95038ef8472f2f7137049acd4236bd (from https://www.govinfo.gov/content/pkg/FR-2007-06-05/pdf/E7-10757.pdf)
- Federal Register: https://www.federalregister.gov/documents/2007/06/05/E7-10757/airworthiness-directives-boeing-model-747-200b-747-300-747-400-747-400d-and-747-400f-series
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DD9EC6BC9458D965862572F1005A9FB1.0001
- Page: https://openairdocs.org/proposed/FAA-2007-28352

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-200B, 747-300, 747-400, 747-400D, and 747- 400F series airplanes. This proposed AD would require repetitive inspections of the left- and right-hand flipper door assemblies of the engine core cowls for migrated pins and damaged flipper doors, and corrective actions if necessary. Modification of the hinge assemblies terminates the repetitive inspections. This proposed AD results from two reports of missing flipper doors for the engine core cowls. We are proposing this AD to detect and correct migrated hinge pins and damaged flipper doors, which could allow the flipper door to fall off, resulting in the potential for an engine fire to propagate into the flammable leakage zone of the strut and for the amount of fire extinguishing agent reaching the fire to be diluted, and subsequent uncontained fire in the engine strut.

## Notices in this docket

- Jun 5, 2007: Notice of proposed rulemaking (NPRM). (first notice), FR document E7-10757, comments due Jul 20, 2007 (https://www.federalregister.gov/documents/2007/06/05/E7-10757/airworthiness-directives-boeing-model-747-200b-747-300-747-400-747-400d-and-747-400f-series)

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