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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 2000-NM-102-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 Bombardier Model DHC-8-100, -200, and -300 series airplanes. This proposal would require inspection to determine the orientation of the Wiggins fuel couplers of the fuel tank vent line and scavenge line in the right wing at station 249, and follow-on corrective actions. This action is necessary to prevent contact between the nuts of the Wiggins fuel couplers and the stiffener on the access panel of the upper surface of the right wing, which could compromise the lightning protection of the fuel tank of the right wing in the event of a lightning strike, and could result in possible fuel tank explosion. This action is intended to address the identified unsafe condition. 

# DATES:

Comments must be received by December 7, 2000. 

# ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-102-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-102-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 Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York. 

# FOR FURTHER INFORMATION CONTACT:

Serge Napoleon, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York 11581; telephone (516) 256-7512; fax (516) 568-2716. 

# 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 notice may be changed in light of the comments received. 

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 notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-102-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 No. 2000-NM-102-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. 

## Discussion 

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on certain Bombardier Model DHC-8-100, -200, and -300 series airplanes. TCAA advises that it received a report indicating that a Wiggins fuel coupler had come in contact with the stiffener of the wing access panel at wing station 249. 

Investigation revealed that the Wiggins fuel couplers in the right wing of both the fuel tank vent line and scavenge line had been installed incorrectly, with the nut of each coupler facing the outboard side of the wing, rather than the inboard side. This incorrect installation allowed contact between one nut of the coupler and the stiffener on the access panel of the upper surface of the right wing. Such contact could compromise the lightning protection of the fuel tank of the right wing in the event of a lightning strike, and could result in possible fuel tank explosion. 

## Explanation of Relevant Service Information 

                    The manufacturer has issued Bombardier Alert Service Bulletin A8-28-32, dated January 14, 2000, which describes procedures for a one-time general visual or x-ray inspection to determine the orientation of the Wiggins fuel couplers of the fuel tank vent line                           ( print page 66658)                        and scavenge line in the right wing at station 249. For airplanes on which the couplers are oriented correctly, the alert service bulletin describes procedures for rework of the stiffener on the access panel of the upper surface of the right wing. For airplanes on which any incorrectly oriented coupler is found, the alert service bulletin describes procedures for removal of the coupler and a one-time detailed visual inspection to detect damage of that coupler.                 

For airplanes on which no damaged coupler is found, the alert service bulletin describes procedures for reinstallation of the coupler in the correct orientation and rework of the stiffener on the access panel of the upper surface of the right wing. However, for airplanes on which any damaged coupler is found, the alert service bulletin describes procedures for blending out the damage and performing a detailed visual inspection of the fuel coupler for cracks; and reinstallation of the coupler in the correct orientation and rework of the stiffener on the access panel of the upper surface of the right wing, or replacement of the coupler with a new or serviceable coupler in the correct orientation and rework the stiffener on the access panel of the upper surface of the right wing, if necessary. 

Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. TCAA classified this alert service bulletin as mandatory and issued Canadian airworthiness directive CF-2000-05, dated February 28, 2000, in order to assure the continued airworthiness of these airplanes in Canada. 

## FAA's Conclusions 

This airplane model is manufactured in Canada 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, TCAA has kept the FAA informed of the situation described above. The FAA has examined the findings of TCAA, 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 alert service bulletin described previously, except as discussed below. 

## Differences Between This Proposed AD and Relevant Service Information 

Operators should note that certain compliance times specified in this proposed AD differ from those specified in the alert service bulletin: 
    - For airplanes having correctly oriented fuel couplers, the alert service bulletin recommends reworking the stiffener within 5,000 flight hours after the initial inspection. The Canadian airworthiness directive requires the rework “at the next convenient maintenance opportunity but not later than the next ‘C’ check or 5,000 hours flight time after the effective date of this directive, whichever occurs first.” However, this proposed AD would require the rework for these airplanes within 5,000 flight hours after the effective date of the AD.
    - For airplanes having incorrectly oriented fuel couplers, the alert service bulletin also recommends reworking the stiffener within 5,000 flight hours of the initial inspection. However, this proposed AD requires the rework for these airplanes prior to further flight after detecting the incorrect orientation.

In developing the compliance times for this proposed AD, the FAA considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, and the compliance times specified in the Canadian airworthiness directive. In light of these factors, the FAA finds that its proposed compliance times for the rework represent the appropriate intervals of time allowable for affected airplanes to continue to operate without compromising safety. 

## Cost Impact 

The FAA estimates that 195 airplanes of U.S. registry would be affected by this proposed AD. 

It would take approximately 1 work hour per airplane to accomplish the actions (inspection) specified in Part A of the alert service bulletin, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these proposed actions on U.S. operators is estimated to be $11,700, or $60 per airplane. 

It would take approximately 2 work hours per airplane to accomplish the actions (rework) specified in Part B of the alert service bulletin, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these proposed actions on U.S. operators is estimated to be $23,400, or $120 per airplane. 

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 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. 

      ( print page 66659)    
§ 39.13 

2. Section 39.13 is amended by adding the following new airworthiness directive: 

**Bombardier, Inc.**                                 (Formerly de Havilland, Inc.): Docket 2000-NM-102-AD.                            

*Applicability:*                                Model DHC-8-100, -200, and -300 series airplanes having serial numbers 003 through 540 inclusive, certificated in any category.                             

# Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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 contact between the nuts of the Wiggins fuel couplers and the stiffener on the access panel of the upper surface of the right wing, which could compromise the lightning protection of the fuel tank of the right wing in the event of a lightning strike, and could result in possible fuel tank explosion, accomplish the following: 

## General Visual or X-ray Inspection 

(a) Within 90 days after the effective date of this AD: Perform a one-time general visual or x-ray inspection to determine the orientation of the Wiggins fuel couplers of the fuel tank vent line and scavenge line in the right wing at station 249, in accordance with Part A of the Accomplishment Instructions of Bombardier Alert Service Bulletin A8-28-32, dated January 14, 2000. 

## Action for Airplanes Having Correctly Oriented Fuel Couplers 

(b) For airplanes on which the orientation of all Wiggins fuel couplers is found to be correct, as specified in Bombardier Alert Service Bulletin A8-28-32, dated January 14, 2000: Within 5,000 flight hours after the effective date of this AD, rework the stiffener on the access panel of the upper surface of the right wing in accordance with Part B of the Accomplishment Instructions of the alert service bulletin. 

# Note 2:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

## Actions for Airplanes Having an Incorrectly Oriented Fuel Coupler 

(c) For airplanes on which the orientation of any Wiggins fuel coupler is incorrect, as specified in Bombardier Alert Service Bulletin A8-28-32, dated January 14, 2000: Prior to further flight, remove the incorrectly oriented Wiggins fuel coupler, and perform a one-time detailed visual inspection to detect damage of the fuel coupler, in accordance with Part A of the Accomplishment Instructions of the alert service bulletin. 

# Note 3:

For the purposes of this AD, a detailed visual inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(1) If no damage is found: Prior to further flight, reinstall the Wiggins fuel coupler in the correct orientation, as specified in the alert service bulletin, and rework the stiffener on the access panel of the upper surface of the right wing, in accordance with Part B of the Accomplishment Instructions of the alert service bulletin. No further action is required by this AD. 

(2) If any damage is found, prior to further flight, blend out the damage and perform a detailed visual inspection of the fuel coupler for cracks, in accordance with the alert service bulletin. 

(i) If no crack is found, and blending CAN be accomplished to meet the limits specified in the Accomplishment Instructions of the alert service bulletin: Prior to further flight, reinstall the Wiggins fuel coupler in the correct orientation, as specified in the alert service bulletin, and rework the stiffener on the access panel of the upper surface of the right wing, in accordance with Part B of the Accomplishment Instructions of the alert service bulletin. No further action is required by this AD. 

(ii) If any crack is found, or if blending CANNOT be accomplished to meet the limits specified in the Accomplishment Instructions of the alert service bulletin: Prior to further flight, replace the Wiggins fuel coupler with a new or serviceable coupler in the correct orientation, as specified in the alert service bulletin, and rework the stiffener on the access panel of the upper surface of the right wing, in accordance with Part B of the Accomplishment Instructions of the alert service bulletin. No further action is required by 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, New York Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO. 

# Note 4:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

## 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 5:

The subject of this AD is addressed in Canadian airworthiness directive CF-2000-05, dated February 28, 2000.

Issued in Renton, Washington, on November 1, 2000. 

Donald L. Riggin, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. 

[FR Doc. 00-28481 Filed 11-06-00; 8:45 am] 

BILLING CODE 4910-13-P