Airworthiness directives: Boeing,
[Federal Register: January 5, 2000 (Volume 65, Number 3)]
[Proposed Rules]
[Page 401-402]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05ja00-19]
[[Page 401]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-335-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
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 Boeing Model 747 series airplanes. This proposal would require replacement of any brake system accumulator that has aluminum end caps with an accumulator that has stainless steel end caps. This proposal is prompted by reports of fractures of aluminum end caps on brake system accumulators. The actions specified by the proposed AD are intended to prevent high- velocity separation of a brake system accumulator barrel, piston, or end cap, which could result in injury to personnel in the wheel well area, loss of cabin pressurization, loss of certain hydraulic systems, or damage to the fuel line of the auxiliary power unit.
DATES: Comments must be received by February 22, 2000.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-335-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00a.m. and 3:00p.m., Monday through Friday, except Federal holidays.
The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: Barbara Mudrovich, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2983; fax (425) 227-1181.
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.
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 filedin 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 99-NM-335-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. 99-NM-335-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
The FAA has received reports indicating that fracture of aluminum end caps has occurred on brake system accumulators installed on Boeing Model 747 series airplanes. One event resulted in an injury to a maintenance worker. Fracture of the aluminum end caps has been attributed to fatigue cracking caused by stress corrosion or tooling marks. Fracture of an end cap could lead to a rupture of a brake system accumulator, which could result in high velocity separation of the accumulator barrel, piston, or end cap. Such separation could result in injury to personnel in the wheel well area, loss of cabin pressurization, loss of certain hydraulic systems, or damage to the fuel line of the auxiliary power unit.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Service Bulletin 747-32- 2461, dated August 19, 1999, which describes procedures for replacement of any brake system accumulator that has aluminum end caps with an accumulator that has stainless steel end caps. Stainless steel end caps provide added strength and corrosion resistance over aluminum end caps, thereby reducing the potential for separation of the end caps. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously.
Cost Impact
There are approximately 1,217 airplanes of the affected design in the worldwide fleet. The FAA estimates that 324 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per accumulator (airplanes may have three, four, or five accumulators of various types) to accomplish the proposed replacement, and that the average labor rate is $60 per work hour. Required parts would cost approximately between $7,650 and $13,418 per airplane (depending on the number and type of affected accumulators). Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be between $7,830 and $13,718 per airplane.
The cost impact figure discussed above is 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 AD were not adopted.
Regulatory Impact
The regulations proposed herein would 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 proposal would not have sufficient
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federalism implications to warrant the preparation of a Federalism Assessment.
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
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
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Section 39.13 is amended by adding the following new airworthiness directive:
Boeing: Docket 99-NM-335-AD.
Applicability: Model 747 series airplanes; as listed in Boeing Service Bulletin 747-32-2461, dated August 19, 1999; 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 prevent high velocity separation of a brake system accumulator barrel, piston, or end cap; which could result in injury to personnel in the wheel well area, loss of cabin pressurization, loss of certain hydraulic systems, or damage to the fuel line of the auxiliary power unit; accomplish the following:
Replacement
(a) Within 3,000 flight hours after the effective date of this AD, replace any brake system accumulator that has aluminum end caps with an accumulator that has stainless steel end caps in accordance with Boeing Service Bulletin 747-32-2461, dated August 19, 1999.
Spares
(b) As of the effective date of this AD, no person shall install a brake system accumulator having part number BACA11E1 or BACA11E5 on any airplane.
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, Seattle Aircraft Certification Office (ACO), 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, Seattle ACO.
Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.
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.
Issued in Renton, Washington, on December 29, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 00-135Filed1-4-00; 8:45 am]
BILLING CODE 4910-13-U
