# AD 2012-21-03: Aircraft Fuel System

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 747-100 Series, 747-100B Series, 747-100B SUD Series, 747-200B Series, 747-200C Series, 747-200F Series, 747-300 Series, 747SP Series and 747SR Series
- Effective: November 27, 2012
- Published: October 23, 2012, 77 FR 64704–64706
- Issued: October 5, 2012
- Issued as: Final rule
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-17219
- Docket: FAA-2008-0619 (https://www.regulations.gov/docket/FAA-2008-0619)
- Project: 2007-NM-356-AD
- Registered aircraft: 10 may be affected, by airframe or engine model (OpenAirDocs)
- Official PDF: https://openairdocs.org/files/sha256/01/23/012356411e0d769f0505d640db5f94aaf4e2cec92da94913286fc86923d5afb2 (from https://www.govinfo.gov/content/pkg/FR-2012-10-23/pdf/2012-25674.pdf)
- Federal Register: https://www.federalregister.gov/documents/2012/10/23/2012-25674/airworthiness-directives-the-boeing-company-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/71D865F13D6271EB86257AA0004BCDB5.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/2012-21-03

## Summary

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes. This AD was prompted by reports of two in-service occurrences on Model 737-400 airplanes of total loss of boost pump pressure of the fuel feed system, followed by loss of fuel system suction feed capability on one engine, and in-flight shutdown of the engine. This AD requires repetitive operational tests, and corrective actions if necessary. We are issuing this AD to detect and correct loss of the engine fuel suction feed capability of the fuel system, which, in the event of total loss of the fuel boost pumps, could result in dual engine flameout, inability to restart the engines, and consequent forced landing of the airplane.

## The airworthiness directive

1. The authority citation for part 39 continues to read as follows:

## Rule preamble

### Dates

This AD is effective November 27, 2012.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of November 27, 2012.

### Addresses

For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

### For further information contact

Sue Lucier, Aerospace Engineer, Propulsion Branch, ANM-140S, 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: 425-917-6438; fax: 425-917-6590; email: suzanne.lucier@faa.gov.

### Discussion

We issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to the specified products. That SNPRM was published in the Federal Register on July 17, 2012 (77 FR 41934). The original NPRM (73 FR 32245, June 6, 2008) proposed to require performing repetitive operational tests of the engine fuel suction feed of the fuel system, and other related testing if necessary. The SNPRM proposed to require repetitive operational tests, and corrective actions if necessary.

### Comments

We gave the public the opportunity to participate in developing this AD. We have considered the comment received from a single commenter: Boeing concurs with the content of the SNPRM (77 FR 41934, July 17, 2012).

### Conclusion

We reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting the AD as proposed.

### Costs of Compliance

We estimate that this AD will affect 1,080 airplanes of U.S. registry. We estimate the following costs to comply with this AD:

*Estimated Costs*

| Action | Labor cost | Cost per product | Cost on U.S. operators |
| --- | --- | --- | --- |
| Operational Test | 3 work hours × $85 per hour = $255 per engine, per test | $255 | $275,400 per engine, per test. |

We have received no definitive data that would enable us to provide a cost estimate for the on-condition actions or the optional terminating action specified in this AD.

### Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

### Regulatory Findings

This AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

  (1) Is not a “significant regulatory action” under Executive Order 12866,

  (2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),

  (3) Will not affect intrastate aviation in Alaska, and

  (4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

### Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A20WE](https://openairdocs.org/tcds/A20WE): The Boeing Company; names 9 of 14 models: 747-100B Series, 747SP Series, 747-200B Series, 747-200F Series, 747-300 Series, 747-200C Series, 747-100B SUD Series, 747SR Series…

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 10 (10 by airframe model, 0 by engine model)
- Makers: Boeing 10

Models with the most aircraft:

- [Boeing 747-123](https://openairdocs.org/model/boeing-747-123): 2 aircraft (airframe model)
- [Boeing 747-251F](https://openairdocs.org/model/boeing-747-251f): 2 aircraft (airframe model)
- [Boeing 747-257B](https://openairdocs.org/model/boeing-747-257b): 1 aircraft (airframe model)
- [Boeing 747-283B](https://openairdocs.org/model/boeing-747-283b): 1 aircraft (airframe model)
- [Boeing 747-121](https://openairdocs.org/model/boeing-747-121): 1 aircraft (airframe model)
- [Boeing 747-131](https://openairdocs.org/model/boeing-747-131): 1 aircraft (airframe model)
- [Boeing 747-128](https://openairdocs.org/model/boeing-747-128): 1 aircraft (airframe model)
- [Boeing 747-273C](https://openairdocs.org/model/boeing-747-273c): 1 aircraft (airframe model)

All 8 models: https://openairdocs.org/ad/2012-21-03/models.md
Every aircraft: https://openairdocs.org/ad/2012-21-03/aircraft.md

## Related documents

- [Proposed rule FAA-2008-0619](https://openairdocs.org/proposed/FAA-2008-0619): Notice of proposed rulemaking (NPRM), published Jun 6, 2008
- [Proposed rule FAA-2008-0619](https://openairdocs.org/proposed/FAA-2008-0619): Supplemental notice of proposed rulemaking (NPRM); reopening of comment period, published Jul 17, 2012

Its text cites no advisory circulars or STCs.

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