[Federal Register Volume 68, Number 184 (Tuesday, September 23, 2003)]
[Rules and Regulations]
[Pages 55193-55196]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-23932]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-137-AD; Amendment 39-13304; AD 2003-19-02]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 777 series airplanes. This action 
requires inspections of the outboard leading edge slats on the wings 
for installation of seal assemblies with undersized seal inserts and 
missing or gapped inserts, and follow-on and corrective actions if 
necessary. This action also provides for an optional replacement of the 
seal assembly in lieu of the inspections. This action is necessary to 
find and fix such discrepancies, which could result in cracking of the 
slats, subsequent separation of the cove skin, structural damage or 
loss of the trailing edge wedge, and consequent reduced controllability 
of the airplane. This action is intended to address the identified 
unsafe condition.

DATES: Effective October 8, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 8, 2003.
    Comments for inclusion in the Rules Docket must be received on or 
before November 24, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-137-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 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: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2003-NM-137-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 or 2000 or 
ASCII text.
    The service information referenced in this AD 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; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Gary Oltman, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6443; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Related AD

    This AD is related to AD 2002-11-06, amendment 39-12767 (67 FR 
38587, June 5, 2002), applicable to certain Boeing Model 777 series 
airplanes. Boeing Alert Service Bulletin 777-57A0034, Revision 2, dated 
November 19, 1998; Revision 3, dated May 4, 2000; Revision 4, dated 
July 20, 2000; and Revision 5, dated January 25, 2001; were referenced 
as the appropriate sources of service information for accomplishment of 
the required actions. That AD supersedes AD 2000-19-08, amendment 39-
11909 (65 FR 57282, September 22, 2000), to continue to require 
repetitive detailed visual inspections to detect cracking of the 
coveskin on the outboard leading edge slats, and corrective actions, if 
necessary. AD 2002-11-06 also continues to provide for an optional 
modification that significantly increases the repetitive inspection 
interval, and expands the applicability of AD 2000-19-08 by mandating 
the currently required inspections, and corrective actions, if 
necessary, for additional airplanes. Also, for airplanes on which the 
optional modification has been accomplished, AD 2002-11-06 requires a 
new one-time inspection for undersized (incorrect diameter) seal 
inserts installed in the spanwise bulb seals on certain slats, and 
replacement of seal assemblies with new assemblies if necessary.

Since the Issuance of That AD

    Since the issuance of AD 2002-11-06, the FAA has received 
information from the manufacturer indicating that Group 4 airplanes may 
have seal assemblies on the outboard leading edge slats on the wings 
that were installed during production with undersized (incorrect 
diameter) inserts. In addition, those inserts may have receded into the 
ends of the seal assemblies.
    We also have received reports of the installation of seal 
assemblies with missing and gapped inserts. These seal assemblies are 
installed on Model 777 series airplanes on which the seal insert 
installation was done per Revision 3, 4, 5, or 6 of the referenced 
service bulletin, and on which the seal inserts were installed during 
production. Investigation revealed that, during installation, the 
inserts were stretched and did not return to the original shape before 
being trimmed and bonded into place. Subsequently, the insert recedes 
into the ends of the seal assembly, and can become unbonded and detach 
from the seal assembly. Additionally, when the seal is stretched during 
installation, the insert can separate at a location along its length 
which allows the seal to recede from the center of the seal assembly. 
Such conditions, if not found and fixed, could result in cracking of 
the slats, subsequent separation of the cove skin, structural damage or 
loss of the trailing edge wedge, and consequent reduced controllability 
of the airplane.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Alert Service Bulletin 777-
57A0034, Revision 7, dated May 22, 2003, which describes procedures for 
inspections of the outboard leading edge slats on the wings for 
installation of seal assemblies with undersized (incorrect diameter) 
seal inserts and missing or gapped inserts, and follow-on and 
corrective actions if necessary. The applicable inspections and follow-
on and corrective actions are specified in Part 5 and Part 6 of the 
Work Instructions of the service bulletin, described below:
    Part 5--Seal Insert Diameter Inspection and Seal Replacement: 
Describes procedures for airplanes on which the seal insert 
installation has been done per Part 4 of the service bulletin. (Part 5 
was added to Revision 6 of the referenced service bulletin for Groups 1 
and 2 airplanes that had done Part 4 of the service bulletin referenced

[[Page 55194]]

in the existing AD.) The procedures specify a one-time inspection of 
the seal assemblies for correct diameter seal inserts on slat numbers 
4, 5, 10, and 11; if the correct diameter insert was installed and the 
insert has receded into the ends of the seal assembly, install an 
insert segment into the ends of the seal assembly; if incorrect 
diameter seal inserts are installed or the inspection was inconclusive, 
replace the seal assembly with a new seal assembly. If the correct 
diameter insert is installed and the insert has not receded into the 
ends of the seal assembly, no further action is specified for Part 5.
    Part 6--Seal Insert Gap Inspection and Seal Assembly Replacement: 
Describes procedures for all airplanes on which the seal insert 
installation has been done. The procedures specify a one-time 
inspection of the seal assemblies for missing or gapped inserts.
    If the assembly insert is not missing and no gaps are found, the 
procedures in the service bulletin recommend eventual replacement of 
the seal assembly with a new seal assembly as specified in Figure 8 of 
the service bulletin at the time specified in Figure 1 of the service 
bulletin, regardless of apparent condition.
    If the seal assembly insert is missing or gaps are found, the 
procedures specify doing the following:
    For airplanes on which the installation specified in Part 4 has 
been done: Do a cove skin inspection for cracking as specified in Part 
1 of the service bulletin. If no cracking is found, repeat the 
inspection at the intervals specified. If any cracking is found, the 
procedures in the service bulletin specify the applicable actions as 
specified below:
    [sbull] For any crack that is 1.5 inches in length or less, the 
follow-on actions include stop-drilling the cracking, doing an internal 
inspection for cracking as specified in Part 2 of the service bulletin, 
repairing any cracking found, doing a slat adjustment check, and 
repeating the cove skin and internal inspections at the intervals 
specified.
    [sbull] For any crack that is more than 1.5 inches in length, the 
follow-on actions include doing an internal inspection for cracking as 
specified in Part 2 of the service bulletin, repairing any cracking 
found, doing a slat adjustment check, and repeating the cove skin and 
internal inspections at the intervals specified.
    [sbull] As an alternative for all cracks: Replace the slat and do a 
slat adjustment check, then repeat the cove skin and internal 
inspections at the intervals specified.
    If any cracking exceeds certain limits specified in the 777 
Structural Repair Manual, or if internal cracking is found, the service 
bulletin specifies contacting the manufacturer for repair instructions.
    For airplanes on which the seal insert installation was done during 
production, the procedures also include eventual replacement of the 
seal assembly with a new seal assembly as specified in Figure 8 of the 
service bulletin, at the time specified in Figure 1 of the service 
bulletin, regardless of apparent condition.
    Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to find and fix discrepancies of the seal assemblies of 
the outboard leading edge slats on the wings, which could result in 
cracking of the slats, subsequent separation of the cove skin, 
structural damage or loss of the trailing edge wedge, and consequent 
reduced controllability of the airplane. This AD requires inspections 
of the outboard leading edge slats on the wings for installation of 
seal assemblies with undersized (incorrect diameter) seal inserts and 
missing or gapped inserts, and follow-on and corrective actions if 
necessary. This AD also provides for an optional replacement of the 
seal assembly in lieu of the inspections. The actions are required to 
be accomplished in accordance with the service bulletin described 
previously, except as discussed below.

Interim Action

    At this time we are considering a separate rulemaking action to 
supersede this AD to address the procedures for long-term follow-on 
inspections to find additional cracking, and repair of any cracking 
found, as described in the service bulletin. Due to the urgency of the 
need to inspect the fleet and repair any cracking found, this AD will 
address only the sections in the service bulletin that pertain to the 
inspections and follow-on and corrective actions specified in Part 5 
and Part 6 of the service bulletin.
    In addition to superseding this AD, that rulemaking action would 
also supersede AD 2002-11-06 to mandate replacement of the seal 
assemblies with new seal assemblies for all 777 series airplanes. 
However, the planned compliance time for these actions is sufficiently 
long so that prior notice and time for public comment will be 
practicable.

Differences Between This AD and the Service Bulletin

    The service bulletin specifies that the manufacturer may be 
contacted for disposition of certain repair conditions; however, this 
AD requires the repair of those conditions to be accomplished per a 
method approved by the FAA, or per data meeting the type certification 
basis of the airplane approved by a Boeing Company Designated 
Engineering Representative who has been authorized by the Manager, 
Seattle Aircraft Certification Office, to make such findings.

Clarification of Part Numbers for Installation

    Boeing Alert Service Bulletin 777-57A0034, Revision 7, dated May 
22, 2003, contains certain incorrectly identified part numbers (P/N) in 
the ``Existing Part Number'' and ``New Part Number'' columns of the 
table under Appendix A, rows 20 and 27 of page 79, and rows 8 and 10 of 
page 80; respectively. We have been advised that the manufacturer will 
issue a revision to this alert service bulletin to correct the error. 
The part numbers are corrected in the tables below:

                           Table: Part Numbers
------------------------------------------------------------------------
      Existing P/N                 Name                Correct P/N
------------------------------------------------------------------------
114W4140-21.............  Slat Assy--No. 11....  114W4140-22
114W4705-42.............  Seal.................  114W4705-41
------------------------------------------------------------------------


                           Table: Part Numbers
------------------------------------------------------------------------
         New P/N                   Name                Correct P/N
------------------------------------------------------------------------
114W4150-23.............  Slat Assy--No. 5.....  114W4150-29
114W4150-24.............  Slat Assy--No. 10....  114W4150-30
------------------------------------------------------------------------

Changes to 14 CFR Part 39/Effect on the AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance. Because we have now included this material in part 39, we 
no longer need to include it in each individual AD; however, this AD 
identifies the office authorized to approve alternative methods of 
compliance.

[[Page 55195]]

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Submit comments using the following format:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the AD is 
being requested.
    [sbull] 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 rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2003-NM-137-AD.'' The postcard will be date stamped 
and returned to the commenter.

Regulatory Impact

    The regulations adopted herein will 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 final rule does not have federalism 
implications under Executive Order 13132.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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

0
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

0
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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2003-19-02 Boeing: Amendment 39-13304. Docket 2003-NM-137-AD.

    Applicability: Model 777 series airplanes, line numbers 1 
through 412 inclusive, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent cracking of the leading edge outboard slats, which 
could result in separation of the cove skin, structural damage or 
loss of the trailing edge wedge, and consequent reduced 
controllability of the airplane, accomplish the following:

Inspections and Follow-On Actions

    (a) For all airplanes: Within 90 days after the effective date 
of this AD; do a detailed inspection of the seal assemblies of the 
outboard leading edge slats on the wings for missing or gapped 
inserts; then do the applicable follow-on actions by doing all the 
actions per paragraphs 1. through 7. of Part 6, ``Seal Insert Gap 
Inspection and Seal Assembly Replacement,'' of the Work Instructions 
of Boeing Alert Service Bulletin 777-57A0034, Revision 7, dated May 
22, 2003 (including replacing the seal assembly, doing a cove skin 
inspection for cracking, doing an internal inspection for cracking, 
doing a slat adjustment check, repeating the cove skin and internal 
inspections, replacing the slat and doing a slat adjustment check). 
Any applicable follow-on actions must be done at the applicable time 
specified in Figure 1, Sheets 12 through 15 inclusive, of the 
service bulletin.

    Note 1: For the purposes of this AD, a detailed 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) For airplanes identified as ``Group 4'' in Boeing Alert 
Service Bulletin 777-57A0034, Revision 7, dated May 22, 2003: Within 
500 flight cycles after the effective date of this AD; do a detailed 
inspection of the seal inserts of the seal assemblies of the 
outboard leading edge slats on the wings for undersized (incorrect 
diameter) seal inserts; do the applicable follow-on and corrective 
actions by doing all the actions per paragraphs 1. through 8. of 
Part 5, ``Seal Insert Inspection and Seal Replacement,'' of the Work 
Instructions of the service bulletin. Any applicable follow-on 
actions must be done at the applicable time specified in Figure 1, 
Sheet 11, of the service bulletin.

    Note 2: For airplanes identified as ``Group 4'' in Boeing Alert 
Service Bulletin 777-57A0034, Revision 7, dated May 22, 2003 
(outboard slat numbers 4, 5, 10, and 11): If a seal insert has 
receded, when accomplishing paragraph (a) of this AD, operators 
should be careful not to install a repair segment prior to 
inspecting for an undersized diameter insert, as required by 
paragraph (b) of this AD.

Corrective Actions

    (c) If any discrepancy is found during any inspection required 
by this AD: Before further flight, do all applicable corrective 
actions specified in Part 1, Part 2, Part 3, Part 5, and Part 6 of 
the Work Instructions of Boeing Alert Service Bulletin 777-57A0034, 
Revision 7, dated May 22, 2003. Do the applicable corrective actions 
per the service bulletin. If the service bulletin specifies to 
contact the manufacturer for appropriate action: Before further 
flight, repair per a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA, or

[[Page 55196]]

per data meeting the type certification basis of the airplane 
approved by a Boeing Company Designated Engineering Representative 
who has been authorized by the Manager, Seattle ACO, to make such 
findings.

Part Installation

    (d) As of the effective date of this AD, no one may install a 
seal assembly with a part number listed in the ``Existing Part 
Number'' column of the table under Appendix A of Boeing Alert 
Service Bulletin 777-57A0034, Revision 7, dated May 22, 2003; on any 
airplane.

Clarification of Part Numbers for Installation

    (e) Boeing Alert Service Bulletin 777-57A0034, Revision 7, dated 
May 22, 2003, contains certain incorrectly identified part numbers 
(P/N) in the ``Existing Part Number'' and ``New Part Number'' 
columns of the table under Appendix A, rows 20 and 27 of page 79, 
and rows 8 and 10 of page 80; respectively. This AD requires 
operators to remove/install parts having the correct part numbers, 
as specified in Tables 1 and 2 of this AD:

                         Table 1.--Part Numbers
------------------------------------------------------------------------
      Existing P/N                 Name                Correct P/N
------------------------------------------------------------------------
114W4140-21.............  Slat Assy--No. 11....  114W4140-22
114W4705-42.............  Seal.................  114W4705-41
------------------------------------------------------------------------


                         Table 2.--Part Numbers
------------------------------------------------------------------------
         New P/N                   Name                Correct P/N
------------------------------------------------------------------------
114W4150-23.............  Slat Assy--No. 5.....  114W4150-29
114W4150-24.............  Slat Assy--No. 10....  114W4150-30
------------------------------------------------------------------------

Alternative Methods of Compliance

    (f)(1) In accordance with 14 CFR 39.19, the Manager, Seattle 
ACO, is authorized to approve alternative methods of compliance for 
this AD.
    (2) An AMOC that provides an acceptable level of safety may be 
used for a repair required by this AD, if it is approved by a Boeing 
Company Designated Engineering Representative who has been 
authorized by the Manager, Seattle ACO, to make such findings.

Incorporation by Reference

    (g) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Boeing Alert Service Bulletin 777-57A0034, 
Revision 7, dated May 22, 2003. 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 
Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 
98124-2207. 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.

Effective Date

    (h) This amendment becomes effective on October 8, 2003.

    Issued in Renton, Washington, on September 10, 2003.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-23932 Filed 9-22-03; 8:45 am]
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