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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. 2000-NM-371-AD]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration, DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain BAE Systems (Operations) Limited Model Avro 146-RJ series airplanes. This proposal would require inspection to detect incorrect wiring of the fire extinguisher bottles located on the engines and on the auxiliary power unit (APU), and corrective action, as necessary. It would also require modification of the wiring of the fire extinguisher bottles located on the engines and on the APU. This action is prompted by reports of incorrect wiring of the fire extinguisher bottles on the engines and the APU discovered during routine maintenance. This action is necessary to prevent the failure of the fire extinguisher bottles to discharge, which could result in the inability to extinguish a fire in the engines or in the APU.

# DATES:

Comments must be received by May 25, 2001.

# ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-371-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2000-NM-371-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from British Aerospace Regional Aircraft American Support, 13850 Mclearen Road, Herndon, Virginia 20171. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

# FOR FURTHER INFORMATION CONTACT:

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

# SUPPLEMENTARY INFORMATION:

## Comments Invited

                    Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.                          ( print page 20767)    

Submit comments using the following format:
    - Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
    - For each issue, state what specific change to the proposed AD is being requested.
    - Include justification ( e.g.,                      reasons or data) for each request.                

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-371-AD.” The postcard will be date stamped and returned to the commenter.

## Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket Number 2000-NM-371-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

## Discussion

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified the FAA that an unsafe condition may exist on certain BAE Systems (Operations) Limited Model Avro 146-RJ series airplanes. The CAA advises that two incidents of incorrect wiring of the fire extinguisher bottles located on the engines and on the auxiliary power unit (APU) were found during routine maintenance. This condition, if not corrected, could result in the failure of the fire extinguisher bottles to discharge, which could result in the inability to extinguish a fire in the engines or in the APU.

## Explanation of Relevant Service Information

BAE Systems (Operations) Limited has issued Inspection Service Bulletin ISB.26-60, Revision 2, dated January 18, 2001, which describes procedures for a one-time inspection consisting of a “continuity check” to detect incorrect wiring of the fire extinguisher bottles located on the engines and on the APU. The service bulletin also describes procedures for disconnection of incorrect wiring which is detected and reconnection to the correct terminals. The CAA classified this service bulletin as mandatory and issued British airworthiness directive 002-09-2000, in order to assure the continued airworthiness of these airplanes in the United Kingdom.

In addition, BAE Systems (Operations) Limited has issued Modification Service Bulletins SB.26-060-01688A, dated January 18, 2001, which describes procedures for modification of the wiring of the fire extinguisher bottles located on the engines, and SB.26-061-36220A, dated January 18, 2001, which describes procedures for modification of the wiring of the fire extinguisher bottle located on the APU. The modification described in each service bulletin involves installation of new identification sleeves and earth connection adapters on the fire extinguisher bottles. Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition.

## FAA's Conclusions

This airplane model is manufactured in the United Kingdom and is 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 CAA has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

## Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletins described previously.

## Cost Impact

The FAA estimates that 44 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to accomplish the proposed inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed inspection on U.S. operators is estimated to be $2,640, or $60 per airplane.

It is estimated that it would take approximately 4 work hours per airplane to accomplish the proposed modification of the wiring of the fire extinguisher bottles on the engines, and that the average labor rate is $60 per work hour. According to the applicable service bulletin, the cost of required parts is to be arranged between BAE Systems and the operator. Based on these figures, the cost impact of the proposed modification on U.S. operators is estimated to be $10,560, or $240 per airplane, not including any costs to the operator for required parts.

It is estimated that it would take approximately 1 work hour per airplane to accomplish the proposed modification of the wiring of the fire extinguisher bottles on the APU, and that the average labor rate is $60 per work hour. According to the applicable service bulletin, the cost of required parts is to be arranged between BAE Systems and the operator. Based on these figures, the cost impact of the proposed modification on U.S. operators is estimated to be $2,640, or $60 per airplane, not including any costs to the operator for required parts.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

## Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

                    For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT                           ( print page 20768)                        Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption                     **ADDRESSES.**

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Safety

## The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive:

**BAE Systems (Operations) Limited (Formerly British Aerospace Regional Aircraft):**                                 Docket 2000-NM-371-AD.                            

*Applicability*: Model Avro 146-RJ series airplanes, certificated in any category, with modifications HCM01582A, HCM01582B, HCM36192A, or HCM36192B embodied.                            

# Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

*Compliance:*                                 Required as indicated, unless accomplished previously.                            

To prevent the failure of the fire extinguisher bottles on the engines or on the auxiliary power unit (APU) to discharge, which could result in the inability to extinguish a fire in the engines or in the APU, accomplish the following:

## Inspection

(a) Within 90 days after the effective date of this AD: Perform a one-time inspection consisting of a “continuity check” to detect incorrect wiring on the fire extinguisher bottles located on the engines and on the APU, in accordance with the Accomplishment Instructions of BAE Systems (Operations) Limited Inspection Service Bulletin ISB.26-60, dated September 4, 2000, or Revision 1, dated October 10, 2000. If incorrect wiring is detected, prior to further flight, correct the wiring in accordance with the service bulletin.

## Repeat Inspection

(b) Following any maintenance work, including a complete engine change, that affects the wiring of the fire extinguisher bottles located on the engines or on the APU and prior to further flight thereafter: Perform the inspection required by paragraph (a) of this AD. If incorrect wiring is detected, prior to further flight, correct the wiring in accordance with BAE Systems (Operations) Limited Modification Service Bulletin SB.26-061-36220A or SB.26-060-01688A, both dated January 18, 2001, as applicable.

## Modification

(c) Within one year after the effective date of this AD: Modify the wiring of the fire extinguisher bottles located on the engines, in accordance with the Accomplishment Instructions of BAE Systems (Operations) Limited Modification Service Bulletin SB.26-060-01688A, dated January 18, 2001, and modify the wiring of the fire extinguisher bottle located on the APU, in accordance with the Accomplishment Instructions of BAE Systems (Operations) Limited Modification Service Bulletin SB.26-061-36220A, dated January 18, 2001. Accomplishment of these actions constitutes terminating action for the requirements of this AD.

## Alternative Methods of Compliance

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

# Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

## Special Flight Permits

(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

# Note 3:

The subject of this AD is addressed in British airworthiness directive 002-09-2000.

Issued in Renton, Washington, on April 18, 2001.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 01-10179 Filed 4-24-01; 8:45 am]

BILLING CODE 4910-13-P