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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. FAA-2007-27494; Directorate Identifier 2006-NM-269-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration (FAA), DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM). 

# SUMMARY:

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: 

It has been found that both fuel level control units (LCU) and their associated harnesses throughout the aircraft does not comply with the requirements of proper segregation, in order to preclude a possible ignition source in the vicinity of the fuel tanks, as required by SFAR (Special Federal Aviation Regulation) 88 regulations.

The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI. 

# DATES:

We must receive comments on this proposed AD by April 9, 2007. 

# ADDRESSES:

You may send comments by any of the following methods: 
      -  DOT Docket Web site:                          Go to                          http://dms.dot.gov                          and follow the instructions for sending your comments electronically.                     
      -  Fax:                          (202) 493-2251.                     
      -  Mail:                          Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001.                     
      -  Hand Delivery:                          Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.                     
      -  Federal eRulemaking Portal :                          http://www.regulations.gov . Follow the instructions for submitting comments.                     

## Examining the AD Docket 

                    You may examine the AD docket on the Internet at                     *http://dms.dot.gov;*                     or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone (800) 647-5227) is in the                     **ADDRESSES**                     section. Comments will be available in the AD docket shortly after receipt.                 

# FOR FURTHER INFORMATION CONTACT:

Dan Rodina, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-2125; fax (425) 227-1149. 

# SUPPLEMENTARY INFORMATION:

 

## Streamlined Issuance of AD 

                    The FAA is implementing a new process for streamlining the issuance of ADs related to MCAI. This streamlined process will allow us to adopt MCAI safety requirements in a more efficient manner and will reduce safety risks to the public. This process continues to follow all FAA AD issuance processes to meet legal, economic, Administrative Procedure Act, and                     **Federal Register**                     requirements. We also continue to meet our technical decision-making responsibilities to identify and correct unsafe conditions on U.S.-certificated products.                 

This proposed AD references the MCAI and related service information that we considered in forming the engineering basis to correct the unsafe condition. The proposed AD contains text copied from the MCAI and for this reason might not follow our plain language principles. 

## Comments Invited 

                    We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the                     **ADDRESSES**                     section. Include “Docket No. FAA-2007-27494; Directorate Identifier 2006-NM-269-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on those comments.                 

                    We will post all comments we receive, without change, to                     *http://dms.dot.gov,*                     including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.                 

## Discussion 

The Agência Nacional de Aviação Civil (ANAC), which is the aviation authority for Brazil, has issued Brazilian Airworthiness Directive 2006-09-05, dated October 18, 2006 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states: 

It has been found that both fuel level control units (LCU) and their associated harnesses throughout the aircraft does not comply with the requirements of proper segregation, in order to preclude a possible ignition source in the vicinity of the fuel tanks, as required by SFAR (Special Federal Aviation Regulation) 88 regulations.

The MCAI requires replacing the fuel LCU 1 and LCU 2; reworking the LCU 1 and LCU 2 supports; and segregating, replacing, and reworking some harnesses. You may obtain further information by examining the MCAI in the AD docket. 

                    The FAA has examined the underlying safety issues involved in fuel tank explosions on several large transport airplanes, including the adequacy of existing regulations, the service history of airplanes subject to those regulations, and existing maintenance practices for fuel tank systems. As a result of those findings, we issued a regulation titled “Transport Airplane Fuel Tank System Design Review, Flammability Reduction and Maintenance and Inspection Requirements” (66 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and new maintenance requirements, this rule included Special Federal Aviation Regulation No. 88 (“SFAR 88,” Amendment 21-78, and subsequent Amendments 21-82 and 21-83).                           ( print page 10430)    

Among other actions, SFAR 88 requires certain type design (i.e., type certificate (TC) and supplemental type certificate (STC)) holders to substantiate that their fuel tank systems can prevent ignition sources in the fuel tanks. This requirement applies to type design holders for large turbine-powered transport airplanes and for subsequent modifications to those airplanes. It requires them to perform design reviews and to develop design changes and maintenance procedures if their designs do not meet the new fuel tank safety standards. As explained in the preamble to the rule, we intended to adopt airworthiness directives to mandate any changes found necessary to address unsafe conditions identified as a result of these reviews. 

In evaluating these design reviews, we have established four criteria intended to define the unsafe conditions associated with fuel tank systems that require corrective actions. The percentage of operating time during which fuel tanks are exposed to flammable conditions is one of these criteria. The other three criteria address the failure types under evaluation: single failures, single failures in combination with a latent condition(s), and in-service failure experience. For all four criteria, the evaluations included consideration of previous actions taken that may mitigate the need for further action. 

We have determined that the actions identified in this AD are necessary to reduce the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane. 

## Relevant Service Information 

EMBRAER has issued Service Bulletin 145LEG-28-0020, dated February 18, 2005. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI. 

## FAA's Determination and Requirements of This Proposed AD 

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with this State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design. 

## Differences Between This AD and the MCAI or Service Information 

We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information. 

We might also have proposed different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are highlighted in a NOTE within the proposed AD. 

## Costs of Compliance 

Based on the service information, we estimate that this proposed AD would affect about 2 products of U.S. registry. We also estimate that it would take about 60 work-hours per product to comply with this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $6,931 per product. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these costs. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $23,462, or $11,731 per product. 

## 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 

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:*

1. Is not a “significant regulatory action” under Executive Order 12866; 

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

3. 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. 

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. 

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Safety

## The Proposed Amendment 

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

# PART 39—AIRWORTHINESS DIRECTIVES 

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

Authority:49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 

2. The FAA amends § 39.13 by adding the following new AD: 

**EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER):**                                 Docket No. FAA-2007-27494; Directorate Identifier 2006-NM-269-AD.                             

## Comments Due Date 

(a) We must receive comments by April 9, 2007. 

## Affected ADs 

(b) None. 

## Applicability 

(c) This AD applies to EMBRAER Model EMB-135BJ airplanes, certificated in any category, serial numbers 145484, 145540, 145555, 145706, and 145711. 

## Subject 

(d) Fuel. 

## Reason 

(e) The mandatory continuing airworthiness information (MCAI) states: 

                                ``It has been found that both fuel level control units (LCU) and their associated harnesses throughout the aircraft does not comply with                                       ( print page 10431)                                    the requirements of proper segregation, in order to preclude a possible ignition source in the vicinity of the fuel tanks, as required by SFAR (Special Federal Aviation Regulation) 88 regulations.''                            

The MCAI requires replacing the fuel LCU 1 and LCU 2; reworking the LCU 1 and LCU 2 supports; and segregating, replacing, and reworking some harnesses. 

## Actions and Compliance 

(f) Within 48 months or 5,000 flight hours after the effective date of this AD, whichever occurs first, unless already done, do the following actions: Replace LCU 1 and LCU 2 by new ones bearing P/N (part number) 367-340-001, rework the LCU 1 and LCU 2 supports, rework and segregate electrical harnesses W102S and W102P, replace harnesses W164 and W221, and route electrical harnesses W1614 and W1620 segregating W1614, according to the detailed instructions and procedures described in EMBRAER Service Bulletin 145LEG-28-0020, dated February 18, 2005. 

## FAA AD Differences 

# Note:

This AD differs from the MCAI and/ or service information as follows: No differences.

## Other FAA AD Provisions 

(g) The following provisions also apply to this AD: 

                                (1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA,                                 *ATTN:*                                 Dan Rodina, Aerospace Engineer, 1601 Lind Avenue, SW., Renton, Washington 98057-3356, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.                             

(2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service. 

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act, the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120-0056. 

## Related Information 

(h) Refer to MCAI Brazilian Airworthiness Directive 2006-09-05, effective October 18, 2006; and EMBRAER Service Bulletin 145LEG-28-0020, dated February 18, 2005, for related information. 

Issued in Renton, Washington, on March 1, 2007. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. E7-4128 Filed 3-7-07; 8:45 am] 

BILLING CODE 4910-13-P