# Proposed AD FAA-2014-0450: The Boeing Company Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2014-24-04
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: July 18, 2014, 79 FR 41943
- Comments due: September 2, 2014
- Became: [AD 2014-24-04](https://openairdocs.org/ad/2014-24-04)
- Docket: FAA-2014-0450 (https://www.regulations.gov/docket/FAA-2014-0450, where comments are filed)
- Project: 2013-NM-250-AD
- FR document: 2014-16942
- Official PDF: https://openairdocs.org/files/sha256/c3/d8/c3d8570f1274d29cc6835fe3ce3a969c1d3a6a15b3d5c303902c13954814d475 (from https://www.govinfo.gov/content/pkg/FR-2014-07-18/pdf/2014-16942.pdf)
- Federal Register: https://www.federalregister.gov/documents/2014/07/18/2014-16942/airworthiness-directives-the-boeing-company-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/BA0A492CF73F296A86257D190045865F.0001
- Page: https://openairdocs.org/proposed/FAA-2014-0450

## Summary

We propose to adopt a new airworthiness directive (AD) for all The Boeing Company Model MD-90-30 airplanes. This proposed AD was prompted by reports of cracks emanating from the aft-most barrel nut holes of the left and right upper rear spar caps of the horizontal stabilizer. This proposed AD would require repetitive high frequency eddy current (ETHF) inspections for cracks in the areas around the two aft-most barrel nut holes of the upper rear spar caps, and corrective action if necessary; and repetitive ETHF inspections for cracks in the areas around the two aft-most barrel nut holes of any repaired or replaced upper rear spar cap, and corrective actions if necessary. We are proposing this AD to detect and correct such cracks, which could propagate until the upper rear spar cap severs, and result in failure of the horizontal stabilizer upper center or aft skin panel and adversely affect the structural integrity of the airplane.

## Notices in this docket

- Jul 18, 2014: Notice of proposed rulemaking (NPRM). (first notice), FR document 2014-16942, comments due Sep 2, 2014 (https://www.federalregister.gov/documents/2014/07/18/2014-16942/airworthiness-directives-the-boeing-company-airplanes)

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