AD 99-23-11

This amendment adopts a new airworthiness directive (AD), applicable to certain British Aerospace Model BAe 146 and Avro 146-RJ series airplanes, that requires repetitive inspections to detect signs of chafing to the fuel feed pipe, and repair or replacement of the fuel feed pipe with a serviceable part, if necessary; and ensuring that responder units, electrical connector backshells, and associated wiring are undamaged and are positioned correctly to provide maximum clearance with the fuel pipe. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent damage to the fuel feed pipe, which could result in fuel leaks and an increased potential for fire on the airplane.

Final rule

99-23-11 BRITISH AEROSPACE REGIONAL AIRCRAFT (Formerly British Aerospace Regional Aircraft Limited, Avro International Aerospace Division; British Aerospace, PLC; British Aerospace Commercial Aircraft Limited): Amendment 39-11407. Docket 99-NM-70-AD. Issued November 1, 1999.
Applicability: Model BAe 146 and Avro 146-RJ series airplanes, except those on which Modification HCMO1638A (British Aerospace Service Bulletin SB.26-44-01638A, dated February 25, 1999) has been accomplished; certificated in any category.

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 (c) 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 damage to the fuel feed pipe, which could result in fuel leaks and an increased potential for fire on the airplane, accomplish the following:

(a) Within 30 days after the effective date of this AD, perform a detailed visual inspection of the fuel feed pipe for signs of chafing, and ensure that responder units are undamaged and positioned correctly in relation to clamps and that electrical connector backshells and associated wiring are undamaged and are oriented to provide maximum clearance with the fuel pipe; in accordance with British Aerospace Service Bulletin SB.26-44, dated February 25, 1999.(1) If no chafing is detected, repeat the inspection thereafter at intervals not to exceed 4,000 flight cycles or 2 years, whichever occurs first, until accomplishment of paragraph (b) of this AD.

(2) If any sign of chafing is detected, prior to further flight, accomplish paragraph (a)(2)(i) or (a)(2)(ii) of this AD, as applicable, in accordance with British Aerospace Service Bulletin SB.26-44, dated February 25, 1999. Repeat the inspection thereafter at intervals not to exceed 4,000 flight cycles or 2 years, whichever occurs first, until accomplishment of paragraph (b) of this AD.

(i) If the damage does not exceed one-half the thickness of the fuel feed pipe wall, prior to further flight, repair the pipe.

(ii) If the damage exceeds one-half the thickness of the fuel feed pipe wall, prior to further flight, replace the pipe with a serviceable part.

NOTE 2: 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."

(b) Modification of the clamping arrangement for the firewall responder units in accordance with British Aerospace Service Bulletin SB.26-44-01638A, dated February 25, 1999, constitutes terminating action for the requirements of this AD.

Alternative Methods of Compliance
(c) 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, FAA, Transport Airplane Directorate. 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, FAA, Transport Airplane Directorate.

NOTE 3: 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
(d) 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.

Incorporation by Reference
(e) The actions shall be done in accordance with British Aerospace Service Bulletin SB.26-44, dated February 25, 1999. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from British Aerospace Regional Aircraft American Support, 13850 Mclearen Road, Herndon, Virginia 20171. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 4: The subject of this AD is addressed in British airworthiness directive 009-02-99.

(f) This amendment becomes effective on December 20, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain British Aerospace Model BAe 146 and Avro 146-RJ series airplanes was published in the Federal Register on August 12, 1999 (64 FR 43955). That action proposed to require repetitive inspections to detect signs of chafing to the fuel feed pipe, and repair or replacement of the fuel feed pipe with a serviceable part, if necessary; and ensuring that responder units, electrical connector backshells, and associated wiring are undamaged and are positioned correctly to provide maximum clearance with the fuel pipe.

Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Request to Change the Repetitive Inspection Interval
One commenter, the manufacturer, states that the repetitive inspection interval required by paragraph (a) of the proposed AD is not consistent with the interval described in the service bulletin. The service bulletin indicates that the interval should be at each "C" check, which the manufacturer has confirmed to be at 4,000 flight cycles, or within 2 years, whichever occurs first.

The FAA infers that the commenter is requesting that the inspection interval be revised to correspond to "C" check intervals. The FAA concurs. It was the FAA s intention to require repetitive inspections at an interval corresponding to the majority of operators scheduled "C" checks. The interval in the proposed AD was erroneously stated as 3,000 flight hours. Based on the information provided by the manufacturer, the FAA has revised the repetitive inspection interval in paragraph (a) of the final rule to specify an inspection interval of 4,000 flight cycles, or within 2 years, whichever occurs first.

Request to Change the Cost Impact
The commenter estimates thatthere are 45 U.S.-registered airplanes affected by this AD. In the notice of proposed rulemaking, the FAA had estimated that 20 airplanes were affected.

The FAA concurs and has changed the cost impact paragraph in the final rule to indicate that 45 airplanes are affected by this AD.

Request to Change Service Information Address
The commenter states that the address used to obtain service information has been changed from AI(R) American Support to British Aerospace Regional Aircraft American Support. The remainder of the address is unchanged: 13850 Mclearen Road, Herndon, Virginia 20171.

The FAA concurs and has changed the final rule to indicate the new address.

Conclusion
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
The FAA estimates that 45 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $2,700, or $60 per airplane, per inspection cycle.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact
The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegatedto me by the Administrator, the Federal Aviation Administration amends 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 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: