# Proposed AD FAA-2009-0684: Boeing Model 747-200C and -200F Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2010-07-03
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: August 12, 2009, 74 FR 40529
- Comments due: September 28, 2009
- Became: [AD 2010-07-03](https://openairdocs.org/ad/2010-07-03)
- Docket: FAA-2009-0684 (https://www.regulations.gov/docket/FAA-2009-0684, where comments are filed)
- Project: 2008-NM-149-AD
- FR document: E9-19262
- Official PDF: https://openairdocs.org/files/sha256/ed/5a/ed5af10f420f0d3aacaa8f785144706c26834b593d24359e2f74ca7cfecc22e3 (from https://www.govinfo.gov/content/pkg/FR-2009-08-12/pdf/E9-19262.pdf)
- Federal Register: https://www.federalregister.gov/documents/2009/08/12/E9-19262/airworthiness-directives-boeing-model-747-200c-and--200f-series-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4B0F169E6BFF907F86257610005FB730.0001
- Page: https://openairdocs.org/proposed/FAA-2009-0684

## Summary

The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Boeing Model 747-200C and -200F series airplanes. The existing AD currently requires repetitive inspections to find fatigue cracking in the floor panel attachment fastener holes of the upper chord of certain upper deck floor beams in Section 41 (i.e., body station 520 and forward), and repair if necessary. The existing AD also provides optional modifications, which extend the threshold for the initiation of certain repetitive inspections. This proposed AD would add repetitive inspections to find fatigue cracking in the floor panel attachment fastener holes of the upper chord of certain other upper deck floor beams in Section 41 and Section 42 (i.e., aft of body station 520); repetitive inspections to find fatigue cracking in the permanent fastener holes of the upper chord of certain upper deck floor beams in Section 41; and related investigative and corrective actions. This proposedAD would also provide a new optional modification, which would terminate certain repetitive inspections. This proposed AD results from new reports of cracking in the upper chord of the upper deck floor beams in Sections 41 and 42, and new analysis that shows the permanent fastener holes of the upper chord of certain upper deck floor beams in Section 41 are also susceptible to fatigue cracking. We are proposing this AD to detect and correct cracking in the upper chord of the upper deck floor beams. Such cracking could extend and sever the floor beams, which could result in rapid decompression and loss of controllability of the airplane.

## Notices in this docket

- Aug 12, 2009: Notice of proposed rulemaking (NPRM). (first notice), FR document E9-19262, comments due Sep 28, 2009 (https://www.federalregister.gov/documents/2009/08/12/E9-19262/airworthiness-directives-boeing-model-747-200c-and--200f-series-airplanes)

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