Airworthiness directives: British Aerospace,

[Federal Register: December 28, 1999 (Volume 64, Number 248)]

[Rules and Regulations]

[Page 72522-72524]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr28de99-10]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-331-AD; Amendment 39-11454; AD 99-25-11]

RIN 2120-AA64

Airworthiness Directives; British Aerospace Model BAe 146 and Avro 146-RJ Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a new airworthiness directive (AD), applicable to all British Aerospace Model BAe 146 series airplanes and certain British Aerospace Model Avro 146-RJ series airplanes, that requires repetitive eddy current inspections to detect fatigue cracking along the face of the retraction attachment boss in the nose landing gear sidewall; and corrective action, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil aviation authority. The actions specified by this AD are intended to detect and correct fatigue cracking along the face of the retraction attachment boss in the nose landing gear sidewall, which could result in premature extension of the nose landing gear or depressurization of the airplane.

DATES: Effective February 1, 2000.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of February 1, 2000.

ADDRESSES: The service information referenced in this AD may be obtained from British Aerospace Regional Aircraft American Support, 13850 Mclearen Road, Herndon, Virginia 20171. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: 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 all British Aerospace Model BAe 146 series airplanes and certain British Aerospace Model Avro 146-RJ series airplanes was published in the Federal Register on June 28, 1999 (64 FR 34586). That action proposed to require repetitive eddy current inspections to detect fatigue cracking along the face of the retraction attachment boss in the nose landing gear sidewall; and corrective action, if necessary.

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 Statement of Unsafe Condition

One commenter states that the description of the unsafe condition, as stated in the notice of proposed rulemaking (NPRM), is incorrect. The commenter requests that, instead of stating ``such fatigue cracking, if not corrected, could result in failure of the nose landing gear during take-off and landing,'' the consequence of such fatigue cracking should be stated as ``premature extension of the nose landing gear and/or * * * a depressurization of the aircraft.''

The FAA concurs with the commenter's request. Therefore, the statement of unsafe condition has been revised in the summary and the body of the final rule to correctly state the unsafe condition.

Request To Allow Contact of Manufacturer if Cracks Are Found

One commenter requests that the final rule be revised to state, ``If cracks are found, before further flight[,] either[;]

[[Page 72523]]

contact BAe Customer Support for further advice or repair in accordance with a method approved by the FAA.'' The commenter states that the proposed requirement for repair prior to further flight in accordance with a method approved by the FAA or Civil Aviation Authority (CAA), is too restrictive and could force operators to ground airplanes with cracks along the face of the retraction attachment boss in the nose landing gear sidewall, regardless of crack length. The commenter states that it has demonstrated by test that ultimate loads can be sustained if a crack has extended to the edge of the retraction attachment boss.

The FAA does not concur with the commenter's request. To require operators to contact the manufacturer for repair instructions, as suggested by the commenter, would be delegating the FAA's rulemaking authority to the manufacturer. In addition, because specific repair instructions were not included in the referenced service bulletin and have not been provided to the FAA by the manufacturer, the FAA cannot include specific repair instructions in the final rule. Also, although the manufacturer has advised that it plans to revise the service bulletin to include repair instructions, the FAA does not consider it appropriate to delay issuance of the final rule while awaiting the revised service bulletin.

However, the FAA recognizes that the requirement to repair any crack prior to further flight, regardless of the length of the crack, could be, in this case, unnecessarily restrictive. As stated by the commenter, tests have shown that cracked structure within defined limits can sustain limit loads without failure. Thus, the FAA finds that a stringent repetitive inspection program, acceptable to the FAA or CAA, may provide an acceptable level of safety that would allow for deferment of a permanent repair for a certain period of time. Because the manufacturer has not provided the FAA with such a repetitive inspection program nor criteria to allow a temporary deferral of permanent repair, such instructions cannot be included in the final rule. However, to allow for the possibility of a temporary deferral of repair, paragraph (b) of this final rule has been revised to require, if any crack is detected, repair or reinspection prior to further flight in accordance with a method approved by the FAA or CAA.

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 previously described. 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 44 airplanes of U.S. registry will be affected by this required AD, that it will take approximately 1 work hour per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the required AD on U.S. operators is estimated to be $2,640, 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 delegated to 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.

   Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive: 99-25-11 British Aerospace Regional Aircraft (Formerly British Aerospace Regional Aircraft Limited, Avro International Aerospace Division; British Aerospace, PLC; British Aerospace Commercial Aircraft Limited): Amendment 39-11454. Docket 98-NM-331-AD.

   Applicability: Model BAe 146 and Avro 146-RJ series airplanes, as listed in British Aerospace Service Bulletin SB.53-152, dated October 8, 1998, 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 (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 detect and correct fatigue cracking along the face of the retraction attachment boss in the nose landing gear sidewall, which could result in premature extension of the nose landing gear or result in depressurization of the airplane, accomplish the following:

   Repetitive Inspections

   (a) Prior to the accumulation of 8,000 total flight cycles, or within 200 flight cycles after the effective date of this AD, whichever occurs later, perform an eddy current inspection to detect cracking along the face of the retraction attachment boss in the nose landing gear sidewall, in accordance with British Aerospace Service Bulletin SB.53-152, dated October 8, 1998. Thereafter, repeat the eddy current inspection at intervals not to exceed 2,600 flight cycles.

   Repair

   (b) If any crack is detected, prior to further flight, repair or reinspect in accordance with a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Civil Aviation Authority (or its delegated agent). For a repair method to be approved by the Manager, International Branch, ANM-116, as

   [[Page 72524]]

   required by this paragraph, the Manager's approval letter must specifically reference 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. 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

   (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 inspections shall be done in accordance with British Aerospace Service Bulletin SB.53-152, dated October 8, 1998. 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 3: The subject of this AD is addressed in British airworthiness directive 015-10-98.

   (f) This amendment becomes effective on February 1, 2000.

   Issued in Renton, Washington, on December 1, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-31676Filed12-27-99; 8:45 am]

   BILLING CODE 4910-13-U