# Proposed AD FAA-2008-1275: Boeing Model 737-100, -200, -200C, - 300, -400, and -500 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2009-09-06
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: December 5, 2008, 73 FR 74080
- Comments due: January 20, 2009
- Became: [AD 2009-09-06](https://openairdocs.org/ad/2009-09-06)
- Docket: FAA-2008-1275 (https://www.regulations.gov/docket/FAA-2008-1275, where comments are filed)
- Project: 2007-NM-167-AD
- FR document: E8-28819
- Official PDF: https://openairdocs.org/files/sha256/65/26/6526d5bf097da520eaf900b38d0bdc893d227e1d58fc52074e5380d3351b6c19 (from https://www.govinfo.gov/content/pkg/FR-2008-12-05/pdf/E8-28819.pdf)
- Federal Register: https://www.federalregister.gov/documents/2008/12/05/E8-28819/airworthiness-directives-boeing-model-737-100--200--200c--300--400-and--500-series-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/0238BBE74C97964E86257516004C64F7.0001
- Page: https://openairdocs.org/proposed/FAA-2008-1275

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This proposed AD would require repetitive detailed and high frequency eddy current inspections to detect cracks of the backup intercostals and the upper sill of the forward airstair doorway, and applicable corrective actions. This proposed AD would also provide for an optional terminating action, which would eliminate the need for repetitive inspections. This proposed AD results from a report indicating that cracks were found in the backup intercostals and upper sill web of the forward airstair doorway. We are proposing this AD to detect and correct fatigue cracking of the backup intercostals and upper sill web of the forward airstair doorway, which could result in a rapid loss of cabin pressure.

## Notices in this docket

- Dec 5, 2008: Notice of proposed rulemaking (NPRM). (first notice), FR document E8-28819, comments due Jan 20, 2009 (https://www.federalregister.gov/documents/2008/12/05/E8-28819/airworthiness-directives-boeing-model-737-100--200--200c--300--400-and--500-series-airplanes)

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