# Proposed AD FAA-2007-27525: Boeing Model 747-100, 747-100B, 747- 100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, 747SR, and 747SP Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2007-12-11
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: March 15, 2007, 72 FR 12136
- Comments due: April 30, 2007
- Became: [AD 2007-12-11](https://openairdocs.org/ad/2007-12-11)
- Docket: FAA-2007-27525 (https://www.regulations.gov/docket/FAA-2007-27525, where comments are filed)
- Project: 2006-NM-159-AD
- FR document: E7-4738
- Official PDF: https://openairdocs.org/files/sha256/23/54/2354b41b6f510da9de9292ae4a5585a6c3da6d0581d3fcca645cc73ded6fabdd (from https://www.govinfo.gov/content/pkg/FR-2007-03-15/pdf/E7-4738.pdf)
- Federal Register: https://www.federalregister.gov/documents/2007/03/15/E7-4738/airworthiness-directives-boeing-model-747-100-747-100b-747-100b-sud-747-200b-747-200c-747-300
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/ED61A7F747EB3FD78625729F005F869F.0001
- Page: https://openairdocs.org/proposed/FAA-2007-27525

## Summary

The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Boeing Model 747 airplanes. The existing AD currently requires repetitive inspections to detect cracks and/or corrosion of the girt bar support fitting at certain main entry doors (MED), and repair or replacement of the support fitting. The existing AD also provides for various terminating actions for the repetitive inspections. This proposed AD would require the following additional actions: An inspection, for certain airplanes, for correct installation of square and conical washers in the girt bar support fitting; an inspection, for certain other airplanes, to determine if the washers are installed; and related investigative and corrective action if necessary. This proposed AD results from a report that the square and conical washers may be installed incorrectly in the girt bar support fitting on airplanes on which the support fitting was repaired or replaced in accordance with therequirements of the existing AD. We are proposing this AD to detect and correct corrosion of the girt bar support fitting, which could result in separation of the escape slide from the lower door sill during deployment, and subsequently prevent proper operation of the escape slides at the main entry doors during an emergency. We are also proposing this AD to detect and correct incorrect installation of the square and conical washers in the girt bar support fitting, which could result in failure of the escape slide when deployed.

## Notices in this docket

- Mar 15, 2007: Notice of proposed rulemaking (NPRM). (first notice), FR document E7-4738, comments due Apr 30, 2007 (https://www.federalregister.gov/documents/2007/03/15/E7-4738/airworthiness-directives-boeing-model-747-100-747-100b-747-100b-sud-747-200b-747-200c-747-300)

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