[Federal Register Volume 63, Number 198 (Wednesday, October 14, 1998)]
[Proposed Rules]
[Pages 55065-55067]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-27481]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-243-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777-200 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 777-200 
series airplanes. This proposal would require inspections to verify 
correct installation of certain fasteners located on the trailing edges 
of the horizontal and vertical stabilizer; replacement of the existing 
fasteners with new fasteners installed with wet sealant; and follow-on 
actions, if necessary. This proposal is prompted by reports indicating 
that, during manufacture of the horizontal and vertical stabilizers, 
certain fasteners attaching the aluminum ribs and brackets to the 
trailing edges on the empennage were not correctly installed with wet 
sealant. The actions specified by the proposed AD are intended to 
prevent corrosion and possible cracking of those aluminum parts, which 
could result in loss of the attachment of the elevator and rudder to 
the empennage and consequent reduced controllability of the airplane.

DATES: Comments must be received by November 30, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-243-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.
    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: Stan Wood, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2772; 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 filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice

[[Page 55066]]

must submit a self-addressed, stamped postcard on which the following 
statement is made: ``Comments to Docket Number 98-NM-243-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. 98-NM-243-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that, during manufacture of 
the horizontal and vertical stabilizers, which are made primarily of 
graphite composite, certain fasteners attaching the aluminum ribs and 
brackets to the trailing edges on the empennage were not correctly 
installed with wet sealant. If moisture is present this lack of sealant 
results in an electrolytic path between the aluminum components and 
composite structure that could cause corrosion of the aluminum 
components. Such corrosion could lead to the initiation of fatigue 
cracks. This condition, if not corrected, could result in loss of the 
attachment of the elevator and rudder to the empennage and consequent 
reduced controllability of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
777-55A0005, Revision 1, dated June 4, 1998, which describes procedures 
for visual inspections to verify correct installation of certain 
fasteners located on the trailing edges of the horizontal and vertical 
stabilizer, and replacement of the existing fasteners with new 
fasteners installed with wet sealant, if necessary. The alert service 
bulletin also describes follow-on procedures for oversizing the 
fastener holes and applying primer prior to installation of fasteners. 
Accomplishment of the actions specified in the alert 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 alert service bulletin described previously.

Cost Impact

    There are approximately 18 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 2 airplanes of U.S. registry 
would be affected by this proposed AD.
    It would take approximately 331 work hours per airplane to 
accomplish the proposed inspection of the horizontal stabilizer, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$39,720, or $19,860 per airplane.
    It would take approximately 206 work hours per airplane to 
accomplish the proposed inspection of the vertical stabilizer, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$24,720, or $12,360 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 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 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

    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:

Boeing: Docket 98-NM-243-AD.

    Applicability: Model 777-200 series airplanes, line numbers 15 
through 33, excluding line number 18; 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 (b) 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 corrosion and possible cracking of the aluminum ribs 
and brackets of the trailing edges on the empennage, which could 
result in loss of the attachment of the elevator and rudder to the 
empennage and consequent reduced controllability of the airplane, 
accomplish the following:
    (a) Within five years since the date of manufacture of the 
airplane, perform visual inspections of the specified number of 
fasteners installed in each zone on the aluminum ribs and brackets 
located on the trailing edges of the horizontal and vertical 
stabilizer to verify correct installation of fasteners with wet 
sealant, in accordance with Boeing Alert Service Bulletin 777-
55A0005, Revision 1, dated June 4, 1998. Following the inspection, 
oversize the holes for all removed fasteners, apply primer, and 
install new, oversize fasteners with wet sealant, in accordance with 
the alert service bulletin.
    (1) If the fasteners are correctly installed with wet sealant, 
no further action is required for that zone.
    (2) If the fasteners are not correctly installed with wet 
sealant in any zone, remove the remaining fasteners in that zone, 
oversize the holes, apply primer, and install new, oversize 
fasteners with wet sealant, in accordance with the alert service 
bulletin.

[[Page 55067]]

    (3) If it cannot be determined that the fasteners are correctly 
installed with wet sealant, remove and inspect the specified number 
of additional fasteners in that zone, oversize the holes, apply 
primer, and install new, oversize fasteners with wet sealant, in 
accordance with the alert service bulletin.
    (i) If, after removal, all additional fasteners inspected in 
that zone are found to be correctly installed with wet sealant, no 
further action is required for that zone.
    (ii) If, after removal, the fasteners in that zone are found to 
be incorrectly installed, remove all other fasteners in the zone, 
oversize the holes, apply primer, and install new, oversize 
fasteners with wet sealant, in accordance with the alert service 
bulletin.
    (b) 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.

    (c) Special flight permits may be issued in accordance with 
Secs. 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 October 7, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-27481 Filed 10-13-98; 8:45 am]
BILLING CODE 4910-13-U