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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2005-22525; Directorate Identifier 2005-NM-149-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 airplanes listed above. This proposed AD would require modifying the drain system of the auxiliary power unit (APU) by installing a scavenge pump and, for certain airplanes, replacing the APU exhaust assembly. This proposed AD results from a report of fuel leaking from the APU feeding line and accumulating inside the APU compartment because the drain system is inadequate when the APU is running. We are proposing this AD to prevent fuel accumulation and subsequent flammable fuel vapors in the APU cowling, which, combined with an ignition source, could result in a fire or explosion.

# DATES:

We must receive comments on this proposed AD by October 31, 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.

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

# 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-2005-22525; Directorate Identifier 2005-NM-149-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 certain EMBRAER Model EMB-135BJ, -135ER, -135KE, -135KL, and -135LR airplanes; and certain Model EMB-145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP airplanes. Affected airplanes are equipped with Airborne Model C-14 auxiliary power units (APUs). The DAC advises that it has received a report of fuel leaking from the APU feeding line and accumulating inside the APU compartment because the drain system is inadequate when the APU is running. Fuel accumulation and subsequent flammable fuel vapors in the APU cowling, combined with an ignition source, if not corrected, could result in ignition of fuel vapors and fire or explosion

## Relevant Service Information

                    EMBRAER has issued Service Bulletins 145LEG-49-0006 (for Model EMB-135BJ airplanes) and 145-49-0029 (for all remaining affected airplanes), both dated April 20, 2005. The service bulletins describe procedures for modifying the APU compartment drain system by installing a scavenge pump, supports, tubes, and hoses; and reworking the APU installation by removing a combustor drain hose and installing an aluminum round bar to the drain collector. For APUs having certain cowlings, Service Bulletin 145-49-0029 recommends the concurrent accomplishment of the actions specified in EMBRAER Service Bulletin 145-49-0023. Service Bulletin 145-49-0023, Revision 01, dated April 25, 2005, describes procedures for replacing the APU exhaust assembly with a new APU exhaust assembly. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. The DAC                           ( print page 56859)                        mandated the service information and issued Brazilian airworthiness directive 2005-08-05, effective September 6, 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, except as discussed below.

## Difference Between Proposed AD and Brazilian Airworthiness Directive

The Brazilian airworthiness directive applies to “all EMB-145( ) and EMB-135( ) aircraft models in operation, equipped with Model T-62T-40C14 APU.” This proposed AD would further limit the applicability to airplanes having serial numbers below 14500927. We have been informed that airplanes at and above that serial number will be modified in production. This difference has been coordinated with the DAC.

## Costs of Compliance

This proposed AD would affect about 800 airplanes of U.S. registry. The proposed pump installation would take about 15 work hours per airplane, at an average labor rate of $65 per work hour. Required parts would cost about $1,768 or $1,967 per airplane. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $2,194,400-$2,353,600, or $2,743 or $2,942 per airplane.

The number of airplanes subject to the proposed APU exhaust assembly replacement is unknown. If accomplished, this action would take about 6-7 work hours per airplane, at an average labor rate of $65 per work hour. Required parts would cost about $9,828 or $12,844 per airplane. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $10,218-$13,299 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-2005-22525; Directorate Identifier 2005-NM-159-AD.                            

## Comments Due Date

(a) The FAA must receive comments on this AD action by October 31, 2005.

## Affected ADs

(b) None.

## Applicability

(c) This AD applies to EMBRAER Model EMB-135BJ, -135ER, -135KE, -135KL, and -135LR airplanes; and Model EMB-145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP airplanes; certificated in any category; equipped with Model C-14 auxiliary power units (APUs); except those airplanes with serial numbers 14500927 and subsequent.

## Unsafe Condition

(d) This AD results from a report of fuel leaking from the APU feeding line and accumulating inside the APU compartment because the drain system is inadequate when the APU is running. We are issuing this AD to prevent fuel accumulation and subsequent flammable fuel vapors in the APU cowling, which, combined with an ignition source, could result in a fire or explosion.

## 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.

## Installation of Scavenge Pump Drain

(f) Within 5,000 flight hours after the effective date of this AD, modify the APU compartment drain system by installing a scavenge pump on it by doing all actions specified in the Accomplishment Instructions of EMBRAER Service Bulletin 145LEG-49-0006 (for Model EMB-135BJ airplanes) or 145-49-0029 (for all remaining airplanes), both dated April 20, 2005.

## Concurrent Requirements

                                (g) For airplanes with an APU cowling part number (P/N) 145-52979-401 or 145-52979-403: Before or concurrently with the pump drain installation required by paragraph (f) of this AD, replace the APU exhaust assembly by doing all actions specified in the Accomplishment Instructions of EMBRAER Service Bulletin 145-49-0023, Revision 01, dated April 25, 2005. Replacement before the effective date of this AD in accordance with EMBRAER Service Bulletin 145-49-0023, dated November 23, 2004, is also acceptable for compliance with the requirements of this paragraph.                                      ( print page 56860)    

## Alternative Methods of Compliance (AMOCs)

(h)(1) 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.

(2) 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.

## Related Information

(i) Brazilian airworthiness directive 2005-08-05, effective September 6, 2005, also addresses the subject of this AD.

Issued in Renton, Washington, on September 16, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 05-19238 Filed 9-28-05; 8:45 am]

BILLING CODE 4910-13-P