AD 2001-09-13

[Federal Register Volume 66, Number 90 (Wednesday, May 9, 2001)]
[Rules and Regulations]
[Pages 23538-23541]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-11196]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-51-AD; Amendment 39-12220; AD 2001-09-13]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767-200, -300, and -300F 
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 767-200, -300, and -300F series 
airplanes. This action requires inspections for fatigue cracking of the 
horizontal stabilizer pivot bulkhead, and repetitive inspections or 
other follow-on actions. This action also provides a permanent repair, 
which is optional for airplanes with no cracks, and, if accomplished, 
ends the repetitive inspections. This action is necessary to find and 
fix fatigue cracking of the horizontal stabilizer pivot bulkhead and 
adjacent structure, which could result in loss of the horizontal 
stabilizer. This action is intended to address the identified unsafe 
condition.

DATES: Effective May 24, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 24, 2001.
    Comments for inclusion in the Rules Docket must be received on or 
before July 9, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-51-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: 
<a href="/cdn-cgi/l/email-protection#5960743837347430382b3a3634343c372d193f3838773e362f"><span class="__cf_email__" data-cfemail="4e77632f202363272f3c2d2123232b203a0e282f2f60292138">[email&#160;protected]</span></a>. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-51-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 for Windows 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: John Craycraft, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2782; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received reports that fatigue 
cracking of the horizontal stabilizer pivot bulkhead has been found on 
several Boeing Model 767-200, -300, and -300F series airplanes. The 
cracks occurred in the forward and aft outer chords and the outer chord 
splice fitting of the Station 1809.5 bulkhead, just above the 
horizontal stabilizer fitting. Cracking also occurred in the 
intercostals that support the Station 1809.5 bulkhead. Analysis 
indicates that these fatigue cracks occur because the

[[Page 23539]]

flight loads on the horizontal stabilizer in the upper corner of the 
Station 1809.5 bulkhead are higher than expected. Fatigue cracking in 
this area, if not found and fixed, could result in loss of the 
horizontal stabilizer.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 767-53-
0078, Revision 2, dated April 19, 2001, which describes procedures for 
repetitive inspections for fatigue cracking of the horizontal 
stabilizer pivot bulkhead, and follow-on actions, if necessary. The 
inspections include detailed visual, surface high frequency eddy 
current (HFEC), and low frequency eddy current (LFEC) inspections, as 
applicable, of the forward and aft outer chord, aft mid chord, and 
upper and lower intercostals of the Station 1809.5 bulkhead above the 
horizontal stabilizer fitting. If cracking is found in the forward 
outer chord, the service bulletin describes procedures for both a 
permanent repair and a time-limited repair, which allows accomplishment 
of the permanent repair to be deferred, provided that a one-time 
detailed visual inspection for cracks of the chord repair straps is 
done. The permanent repair includes open-hole HFEC inspections for 
cracking of certain fastener holes of the chord and longeron fitting, 
detailed visual inspections for cracking of adjacent structure, and 
installation of new chords, splices, fairings, and brackets. Doing the 
permanent repair eliminates the need for the repetitive inspections 
described in the service bulletin. The permanent repair is provided as 
an optional preventative modification for airplanes on which no 
cracking is found. Throughout the procedures in the service bulletin, 
the service bulletin specifies to contact Boeing for repair 
instructions if cracking is found in areas other than the forward outer 
chord.

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 fatigue cracking of the horizontal 
stabilizer pivot bulkhead and adjacent structure, which could result in 
loss of the horizontal stabilizer. This AD requires accomplishment of 
the actions specified in the service bulletin described previously, 
except as discussed below.

Interim Action

    This is considered to be interim action. The FAA is currently 
considering requiring installation of the permanent repair described in 
the service bulletin, which would constitute terminating action for the 
repetitive inspections required by this AD action. However, the planned 
compliance time for the installation of the modification is 
sufficiently long so that notice and opportunity for prior public 
comment will be practicable.

Differences Between This AD and the Service Bulletin

    The compliance time for the initial inspection required by this AD 
differs from the compliance time for that action in the service 
bulletin. The service bulletin recommends that the initial inspection 
be done before the accumulation of 10,000 total flight cycles, or, if 
the total number of total flight cycles is close to or more than 
10,000, at the earlier of 3,000 flight cycles or 18 months after 
receipt of the service bulletin. In developing an appropriate 
compliance time for this AD, the FAA considered not only the 
manufacturer's recommendation, but the degree of urgency associated 
with addressing the subject unsafe condition and the average 
utilization of the affected fleet. In light of all of these factors, 
the FAA finds a compliance time of 8,000 total flight cycles, or 90 
days after the effective date of this AD, whichever comes later, for 
completing the required actions to be warranted, in that it represents 
an appropriate interval of time allowable for affected airplanes to 
continue to operate without compromising safety.
    This AD also differs from the service bulletin with regard to 
disposition of certain repair conditions of the forward outer chord. 
While the service bulletin specifies that the manufacturer may be 
contacted for disposition of certain repair conditions, this AD 
requires repair of those conditions 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 ACO, to make such findings.
    This AD also differs from the service bulletin in cases where 
cracking is found in the aft outer chord, aft mid chord, or 
intercostals. The logic diagram in Figure 1 of the service bulletin 
specifies to repair cracking in these areas per data from the airplane 
manufacturer, and repeat the detailed visual inspection at the earlier 
of 3,000 flight cycles or 18 months and the HFEC/LFEC inspections at 
the earlier of 6,000 flight cycles or 36 months. For airplanes on which 
cracking is found in the aft outer chord, aft mid chord, or 
intercostals, this AD does not require these repetitive inspections at 
these intervals. The FAA finds that, because the service bulletin does 
not include instructions for repair of cracking in areas other than the 
forward outer chord, repairs of the aft outer chord, aft mid chord, or 
intercostals must be accomplished per a method approved by the FAA, as 
required by paragraph (c)(1) of this AD. The FAA will approve any 
repetitive inspection requirements along with the repair method.

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:
    <bullet> 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.
    <bullet> For each issue, state what specific change to the AD is 
being requested.
    <bullet> 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

[[Page 23540]]

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 2001-NM-51-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

    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:

2001-09-13  Boeing: Amendment 39-12220. Docket 2001-NM-51-AD.
    Applicability: Model 767-200, -300, and -300F series airplanes; 
as listed in Boeing Service Bulletin 767-53-0078, Revision 2, dated 
April 19, 2001; 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 (f) 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 find and fix fatigue cracking of the horizontal stabilizer 
pivot bulkhead and adjacent structure, which could result in loss of 
the horizontal stabilizer, accomplish the following:

Initial Inspections

    (a) Prior to the accumulation of 8,000 total flight cycles, or 
within 90 days after the effective date of this AD, whichever occurs 
later, perform detailed visual, surface high frequency eddy current 
(HFEC), and low frequency eddy current (LFEC) inspections, as 
applicable, for cracking of the forward and aft outer chord, aft mid 
chord, and upper and lower intercostals of the Station 1809.5 
bulkhead. Do the inspections per Boeing Service Bulletin 767-53-
0078, Revision 2, dated April 19, 2001.

    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.''

Repetitive Inspections

    (b) For areas where no cracking is found during the inspection 
per paragraph (a) of this AD: Repeat the inspections in paragraph 
(a) thereafter at the intervals specified in paragraphs (b)(1) and 
(b)(2) of this AD, per Boeing Service Bulletin 767-53-0078, Revision 
2, dated April 19, 2001, until paragraph (d) of this AD has been 
done.
    (1) Repeat the detailed visual inspection every 3,000 flight 
cycles or 18 months, whichever comes first.
    (2) Repeat the surface HFEC and LFEC inspections every 6,000 
flight cycles or 36 months, whichever comes first.

Repair and Follow-On Actions

    (c) If any cracking is found during any inspection required by 
paragraph (a) or (b) of this AD, before further flight, repair per 
paragraph (c)(1) or (c)(2) of this AD, as applicable.
    (1) For cracking of the aft outer chord, aft mid chord, or any 
intercostal: Repair per a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA. For a repair method to be 
approved by the Manager, Seattle ACO, as required by this paragraph, 
the Manager's approval letter must specifically reference this AD.
    (2) For cracking of the forward outer chord: Repair per Boeing 
Service Bulletin 767-53-0078, Revision 2, dated April 19, 2001, 
except as provided by paragraph (e) of this AD. Procedures for 
repair include open-hole HFEC inspections for cracking of certain 
fastener holes of the chord and longeron fitting, detailed visual 
inspections for cracking of adjacent structure, and installation of 
new chords, splices, fairings, and brackets. If the time-limited 
repair is done per the service bulletin, do a detailed visual 
inspection of the repaired area within 1,500 flight cycles or 9 
months after installation of the temporary repair, whichever comes 
first, and do paragraph (c)(2)(i) or (c)(2)(ii) of this AD, per the 
service bulletin.
    (i) If no cracking is found during the inspection of the 
repaired area: Within 3,000 flight cycles or 18 months after 
installation of the time-limited repair, whichever comes first, do 
paragraph (d) of this AD.
    (ii) If any cracking is found during the inspection of the 
repaired area: Before further flight, do paragraph (d) of this AD.

Permanent Repair

    (d) Except as provided by paragraph (e) of this AD, installation 
of the permanent repair of the forward outer chord, including 
accomplishment of all actions specified in Part 4 of the 
Accomplishment Instructions of Boeing Service Bulletin 767-53-0078, 
Revision 2, dated April 19, 2001, terminates the repetitive 
inspections required by this AD.

    Note 3: Installation of the permanent repair per Boeing Service 
Bulletin 767-53-0078, dated October 15, 1998, or Revision 1, dated 
September 9, 1999, is acceptable for compliance with paragraph (d) 
of this AD.

Exception to Repair Instructions

    (e) For repairs of the forward outer chord: Where the service 
bulletin specifies to ask Boeing for repair data, repair per a 
method approved by the Manager, Seattle ACO, 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 ACO, to make such findings. For a 
repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the Manager's approval letter must 
specifically reference this AD.

Alternative Methods of Compliance

    (f) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be

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used if approved by the Manager, Seattle ACO. 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 4: 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

    (g) 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

    (h) Except as provided by paragraphs (c)(1) and (e) of this AD, 
the actions shall be done in accordance with Boeing Service Bulletin 
767-53-0078, Revision 2, dated April 19, 2001. 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

    (i) This amendment becomes effective on May 24, 2001.


    Issued in Renton, Washington, on April 27, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-11196 Filed 5-8-01; 8:45 am]
BILLING CODE 4910-13-P