# Proposed AD FAA-2011-0041: The Boeing Company Model 747-400 and - 400F Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2011-16-06
- Products: Boeing
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: February 10, 2011, 76 FR 7513
- Comments due: March 28, 2011
- Became: [AD 2011-16-06](https://openairdocs.org/ad/2011-16-06)
- Docket: FAA-2011-0041 (https://www.regulations.gov/docket/FAA-2011-0041, where comments are filed)
- Project: 2010-NM-227-AD
- FR document: 2011-2952
- Official PDF: https://openairdocs.org/files/sha256/5a/5e/5a5e2151a38cfb3a0f8487dc36951d6a07b6e7a2a19413b84cb1703468128478 (from https://www.govinfo.gov/content/pkg/FR-2011-02-10/pdf/2011-2952.pdf)
- Federal Register: https://www.federalregister.gov/documents/2011/02/10/2011-2952/airworthiness-directives-the-boeing-company-model-747-400-and--400f-series-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/90D90A8801E232D28625783300545DBC.0001
- Page: https://openairdocs.org/proposed/FAA-2011-0041

## Summary

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD would require a general visual inspection for cracks and holes of the main equipment center (MEC) drip shields, and repairs if necessary; installation of a fiberglass reinforcing overcoat; and, for certain airplanes, installation of stiffening panels to the MEC drip shields. This proposed AD was prompted by a report of a loss of bus control unit number 1 and generator control units numbers 1 and 2 while the airplane was on the ground, and multiple operator reports of cracked MEC drip shields. We are proposing this AD to prevent water penetration into the MEC, which could result in the loss of flight critical systems.

## Notices in this docket

- Feb 10, 2011: Notice of proposed rulemaking (NPRM). (first notice), FR document 2011-2952, comments due Mar 28, 2011 (https://www.federalregister.gov/documents/2011/02/10/2011-2952/airworthiness-directives-the-boeing-company-model-747-400-and--400f-series-airplanes)

---
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.