# Proposed AD FAA-2013-0421: The Boeing Company

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2013-25-05
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: May 16, 2013, 78 FR 28764
- Comments due: July 1, 2013
- Became: [AD 2013-25-05](https://openairdocs.org/ad/2013-25-05)
- Docket: FAA-2013-0421 (https://www.regulations.gov/docket/FAA-2013-0421, where comments are filed)
- Project: 2013-NM-003-AD
- FR document: 2013-11694
- Official PDF: https://openairdocs.org/files/sha256/50/ea/50ea853440e34bf356fb6ab8895be7ee1f9c4579c662c839ff3676c6cdfc0f33 (from https://www.govinfo.gov/content/pkg/FR-2013-05-16/pdf/2013-11694.pdf)
- Federal Register: https://www.federalregister.gov/documents/2013/05/16/2013-11694/airworthiness-directives-the-boeing-company
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DFC06D9AAA77B25586257B6D005E100C.0001
- Page: https://openairdocs.org/proposed/FAA-2013-0421

## Summary

We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 737-300, -400, and -500 series airplanes. This proposed AD was prompted by fuel system reviews conducted by the manufacturer. This proposed AD would require, depending on airplane configuration, replacing fuel pump power control relays with new relays having a ground fault interrupter (GFI) feature, installing ground studs and a bonding jumper, doing certain bonding resistance measurements, and changing the GFI relay position. This proposed AD would also require revising the maintenance program to incorporate certain airworthiness limitations. We are proposing this AD to prevent damage to the fuel pumps caused by electrical arcing that could introduce an ignition source in the fuel tank, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

## Notices in this docket

- May 16, 2013: Notice of proposed rulemaking (NPRM). (first notice), FR document 2013-11694, comments due Jul 1, 2013 (https://www.federalregister.gov/documents/2013/05/16/2013-11694/airworthiness-directives-the-boeing-company)

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.