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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. FAA-2005-22256; Directorate Identifier 2005-NM-113-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT). 

# ACTION:

Notice of proposed rulemaking (NPRM). 

# SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain EMBRAER Model EMB-135 airplanes, and Model EMB-145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP airplanes. This proposed AD would require modification of the upper frame of the firewall for the auxiliary power unit (APU). This proposed AD results from the discovery of a hole in the upper frame of the firewall for the APU. We are proposing this AD to prevent smoke from entering the passenger cabin in the event of a fire in the APU compartment. 

# DATES:

We must receive comments on this proposed AD by October 3, 2005. 

# ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD. 
      - DOT Docket web site: Go to http://dms.dot.gov                          and follow the instructions for sending your comments electronically.                     
      - Government-wide rulemaking web site: Go to http://www.regulations.gov                          and follow the instructions for sending your comments electronically.                     
      - Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., Nassif Building, Room PL-401, Washington, DC 20590.
      - Fax: (202) 493-2251.
      - 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.

Contact Empresa Brasileira de Aeronautica S.A. (EMBRAER), P.O. Box 343—CEP 12.225, Sao Jose dos Campos—SP, Brazil, for service information identified in this proposed AD. 

# FOR FURTHER INFORMATION CONTACT:

Todd Thompson, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1175; fax (425) 227-1149. 

# SUPPLEMENTARY INFORMATION:

## Comments Invited 

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Include the docket number “FAA-2005-22256; Directorate Identifier 2005-NM-113-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of 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 with FAA personnel concerning this proposed AD. Using the search function of that web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the                     **Federal Register**                     published on April 11, 2000 (65 FR 19477-78), or you may visit                     *http://dms.dot.gov*.                 

## Examining the Docket 

                    You may examine the AD docket on the Internet at                     *http://dms.dot.gov*, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the                     **ADDRESSES**                     section. Comments will be available in the AD docket shortly after the Docket Management System receives them.                 

## Discussion 

The Departmento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, notified us that an unsafe condition may exist on all EMBRAER Model EMB-135 airplanes and Model EMB-145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP airplanes. The DAC advises that, during the manufacturing process of the above airplanes, a hole in the auxiliary power unit (APU) firewall was left open. This condition, if not corrected, could result in smoke entering the passenger cabin in the event of a fire in the APU compartment. 

## Relevant Service Information 

EMBRAER has issued Service Bulletins 145LEG-53-0020 (for Model EMB-135BJ airplanes) and 145-53-0057 (for Model EMB-135ER, -135KE, -135KL, and -135LR airplanes, and Model EMB-145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP airplanes), both dated November 30, 2004. The service bulletins describe procedures for modifying the APU firewall upper frame to ensure that there are no holes. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. The DAC mandated the service information and issued Brazilian airworthiness directive 2005-04-03, dated April 30, 2005, to ensure the continued airworthiness of these airplanes in Brazil. 

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

These airplane models are manufactured in Brazil and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DAC has kept the FAA informed of the situation described above. We have examined the DAC's findings, evaluated all pertinent information, and determined that we need to issue an AD for airplanes of this type design that are certificated for operation in the United States. 

Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously. 

## Differences Between Proposed AD and Foreign AD 

Brazilian airworthiness directive 2005-04-03, dated April 30, 2005, is applicable to “all EMBRAER Model EMB-145( ) and EMB-135( ) aircraft models in operation.” However, this does not agree with EMBRAER Service Bulletins 145LEG-53-0020 and 145-53-0057, which state that only certain EMBRAER Model EMB-135 airplanes and Model EMB-145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP airplanes are affected and identify the affected airplanes by serial number. This proposed AD would be applicable only to the airplanes identified in the service bulletins. 

                    Brazilian airworthiness directive 2005-04-03 specifies modifying the                           ( print page 52041)                        APU firewall upper frame, part number (P/N) 145-51249-001. However, the service bulletins specify that the APU firewall upper frame may have P/N 145-51249-001 or 120-10731-001. APU firewall upper frames having either part number are subject to the identified unsafe condition. Therefore, this proposed AD would require modifying the APU firewall upper frame, P/N 145-51249-001 or 120-10731-001.                 

These differences have been coordinated with the DAC. 

## Costs of Compliance 

This proposed AD would affect about 620 airplanes of U.S. registry. The proposed actions would take about 1 work hour per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $40,300, or $65 per airplane. 

## 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 have 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 that the 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. See the                     **ADDRESSES**                     section for a location to examine the regulatory evaluation.                 

# 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD): 

**Empresa Brasileira de Aeronautica S.A. (EMBRAER):**                                 Docket No. FAA-2005-22256; Directorate Identifier 2005-NM-113-AD.                             

## Comments Due Date 

(a) The FAA must receive comments on this AD action by October 3, 2005. 

## Affected ADs 

(b) None. 

## Applicability 

(c) This AD applies to EMBRAER Model EMB-135BJ airplanes, as identified in EMBRAER Service Bulletin 145LEG-53-0020, dated November 30, 2004; and Model EMB-135ER, -135KE, -135KL, and -135LR airplanes, and Model EMB-145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP airplanes, as identified in EMBRAER Service Bulletin 145-53-0057, dated November 30, 2004; certificated in any category. 

## Unsafe Condition 

(d) This AD results from the discovery of a hole in the upper frame of the firewall for the auxiliary power unit (APU). We are issuing this AD to prevent smoke from entering the passenger cabin in the event of a fire in the APU compartment. 

## Compliance 

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. 

## Modification 

(f) Within 2,500 flight hours or 365 days after the effective date of this AD, whichever occurs later, modify the APU firewall upper frame, part number 145-51249-001 or 120-10731-001, in accordance with the Accomplishment Instructions of EMBRAER Service Bulletin 145LEG-53-0020 (for Model EMB-135BJ airplanes); or Service Bulletin 145-53-0057 (for Model EMB-135ER, -135KE, -135KL, and -135LR airplanes; and Model EMB-145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP airplanes); both dated November 30, 2004; as applicable. 

## Alternative Methods of Compliance (AMOCs) 

(g) The Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. 

## Related Information 

(h) Brazilian airworthiness directive 2005-04-03, dated April 30, 2005, also addresses the subject of this AD. 

Issued in Renton, Washington, on August 24, 2005. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, Aircraft Certification Service. 

[FR Doc. 05-17403 Filed 8-31-05; 8:45 am] 

BILLING CODE 4910-13-P