[Federal Register Volume 70, Number 201 (Wednesday, October 19, 2005)]
[Proposed Rules]
[Pages 60744-60747]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-20882]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-22715; Directorate Identifier 2005-NM-108-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede three existing airworthiness 
directives (ADs) that apply to certain Boeing Model 747 airplanes. The 
existing ADs currently require repetitive inspections of the body 
station (BS) 2598 bulkhead, and corrective action if necessary. This 
proposed AD would add a requirement to modify the bulkhead, including a 
one-time inspection and corrective action if necessary, which would 
terminate certain repetitive inspections. This proposed AD would also 
require a post-modification inspection of the modified area. This 
proposed AD results from new reports of cracking in all three areas 
that require inspection in accordance with the existing ADs. We are 
proposing this AD to prevent fatigue cracking of the BS 2598 bulkhead 
structure, which could result in inability of the structure to carry 
horizontal stabilizer flight loads, and reduced controllability of the 
airplane.

DATES: We must receive comments on this proposed AD by December 5, 
2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
    <bullet> Fax: (202) 493-2251.
    <bullet> Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Nicholas Kusz, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6432; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Include the docket number 
``Docket No. FAA-2005-22715; Directorate Identifier 2005-NM-108-AD'' at 
the beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of the 
proposed AD. We will consider all comments received by the closing date 
and may amend the proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or may 
visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone

[[Page 60745]]

(800) 647-5227) is located on the plaza level of the Nassif Building at 
the DOT street address stated in the ADDRESSES section. Comments will 
be available in the AD docket shortly after the Docket Management 
System receives them.

Discussion

    We have issued the ADs listed in the following table.

                                                  Existing ADs
----------------------------------------------------------------------------------------------------------------
                 AD                      Amendment     Federal Register reference           Requirements
----------------------------------------------------------------------------------------------------------------
2001-14-07..........................        39-12318  66 FR 36443 (July 12, 2001).  Repetitive high-frequency
                                                                                     eddy current (HFEC)
                                                                                     inspections to detect
                                                                                     cracking of the bulkhead
                                                                                     frame support at body
                                                                                     station 2598 under the
                                                                                     hinge support fittings of
                                                                                     the horizontal stabilizer,
                                                                                     and repair if necessary.
2001-15-03..........................        39-12337  66 FR 38365 (July 24, 2001).  Repetitive HFEC inspections
                                                                                     to detect cracking of the
                                                                                     forward and aft inner
                                                                                     chords and the splice
                                                                                     fitting of the forward
                                                                                     inner chord of the body
                                                                                     station 2598 bulkhead, and
                                                                                     repair if necessary.
2003-19-08..........................        39-13311  68 FR 54990 (September 22,    Repetitive detailed
                                                       2003).                        inspections to detect
                                                                                     discrepancies of certain
                                                                                     areas of the forward and
                                                                                     aft sides of the body
                                                                                     station 2598 bulkhead, and
                                                                                     repair if necessary.
----------------------------------------------------------------------------------------------------------------

    The existing ADs apply to airplanes having line numbers 1 through 
1307 inclusive. The existing ADs were prompted by reports of fatigue 
cracking on the body station 2598 bulkhead.
    We issued those ADs to detect and correct discrepancies of the 
bulkhead structure, which could result in the inability of the 
structure to carry horizontal stabilizer flight loads, and reduced 
controllability of the airplane.

Actions Since Existing AD Was Issued

    Since we issued those ADs, we have received additional reports of 
cracking in all three of the areas addressed in the existing ADs. The 
cracking was found on Model 747-200B, 747-200F, and 747-400 series 
airplanes. Also, we received a report of cracking found in all three 
areas on one airplane.
    ADs 2001-15-03 and 2003-19-08 considered the requirements ``interim 
action'' and indicated that the manufacturer was developing a 
modification to address the unsafe condition. Those ADs explained that 
we may consider further rulemaking if a modification is developed, 
approved, and available. The manufacturer now has developed such a 
modification, and we have determined that further rulemaking is indeed 
necessary; this proposed AD follows from that determination.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 747-53-2473, dated March 
24, 2005. The service bulletin describes procedures for modifying the 
bulkhead. The modification involves:
    <bullet> Inspecting specified areas using surface high-frequency 
eddy current (HFEC) and open-hole HFEC methods to detect cracks;
    <bullet> Repairing cracks;
    <bullet> Removing the bulkhead upper and lower diagonal braces by 
using a special tool between their attachment fittings to lift and hold 
the horizontal stabilizer;
    <bullet> Installing the following on the aft side of the bulkhead 
on both sides of the airplane: Two web doublers, new upper and lower 
hinge backup fittings, and either a new inner chord or the original 
inner chord that has been inspected for cracks and repaired if 
necessary; and
    <bullet> Installing oversize fasteners at specified locations where 
insurance cuts have been made to remove material that could contain an 
undetected crack.
    AD 2003-19-08 refers to Boeing Alert Service Bulletin 747-53A2467, 
dated July 26, 2001, as the appropriate source of service information 
for the required actions. Boeing has since issued Revision 1, dated 
April 28, 2005. Revision 1 clarifies certain instructions, but the 
procedures are essentially the same as those in the original service 
bulletin.
    AD 2001-14-07 refers to Boeing Service Bulletin 747-53A2449, 
Revision 1, dated May 24, 2001, as the appropriate source of service 
information for the required actions. Boeing has since issued Revision 
2, dated March 14, 2002. Revision 2 clarifies certain instructions, but 
the procedures are essentially the same as those in Revision 1.
    AD 2001-15-03 refers to Boeing Alert Service Bulletin 747-53A2427, 
dated December 17, 1998, and Revision 1, dated October 28, 1999, as the 
appropriate source of service information for the required actions. 
Boeing has since issued Revision 2, dated October 5, 2000, and Revision 
3, dated September 27, 2001. Revisions 2 and 3 clarify certain 
instructions, but the procedures are essentially the same as those in 
the applicable versions cited in AD 2001-15-03.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of the same type design that may be registered in the U.S. at some time 
in the future. For this reason, we are proposing this AD, which would 
supersede ADs 2001-14-07, 2001-15-03, and 2003-19-08. This proposed AD 
would retain the requirements of the existing ADs and add the actions 
specified in the service bulletin described previously, except as 
discussed below.

Difference Between the Proposed AD and the Service Bulletin

    The service bulletin specifies contacting the manufacturer for 
instructions on how to repair certain conditions, but this proposed AD 
would require repairing those conditions by either using a method that 
we approve or using data that meet the certification basis of the 
airplane and that have been approved by an Authorized Representative 
for the Boeing Commercial Airplanes Delegation Option Authorization 
Organization whom we have authorized to make those findings.

[[Page 60746]]

Additional Changes to Existing ADs

    Boeing Commercial Airplanes has received a Delegation Option 
Authorization (DOA). We have revised the existing AD to delegate the 
authority to approve an alternative method of compliance for any repair 
specified in this proposed AD to an Authorized Representative for the 
Boeing Commercial Airplanes DOA rather than the Designated Engineering 
Representative (DER).
    We have changed all references to a ``detailed visual inspection'' 
in the existing ADs to ``detailed inspection'' in this action. Note 1 
in this proposed AD defines a detailed inspection.
    In the existing ADs, credit for accomplishment of a prior revision 
of a service bulletin was provided in a note; in this proposed AD, that 
language has been added to paragraph (f).

Costs of Compliance

    There are about 1,147 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                           Number of
                                                                         Average                                             U.S.-
                         Actions                           Work hours     hourly          Parts        Cost per airplane   registered      Fleet cost
                                                                        labor rate                                         airplanes
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Inspection required by AD 2001-14-07 (per inspection               18          $65                 $0             $1,170          280           $327,600
 cycle).................................................
HFEC inspection required by AD 2001-15-03 (per                      2           65                  0                130          280             36,400
 inspection cycle)......................................
Detailed inspection required by AD 2001-15-03 (per                  2           65                  0                130          280             36,400
 inspection cycle)......................................
Inspection required by AD 2003-19-08 (per inspection                4           65                  0                260          280             72,800
 cycle).................................................
Proposed modification...................................          126           65             33,716             41,906          280         11,733,680
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Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-12318 (66 FR 36443, July 12, 2001), amendment 39-
12337 (66 FR 38365, July 24, 2001), and amendment 39-13311 (68 FR 
54990, September 22, 2003), and adding the following new airworthiness 
directive (AD):

Boeing: Docket No. FAA-2005-22715; Directorate Identifier 2005-NM-
108-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by December 
5, 2005.

Affected ADs

    (b) This AD supersedes the ADs listed in Table 1 of this AD.

                        Table 1.--Superseded ADs
------------------------------------------------------------------------
                    AD                                Amendment
------------------------------------------------------------------------
AD Amendment 2001-14-07...................  Amendment 39-12318.
AD Amendment 2001-15-03...................  Amendment 39-12337.
AD Amendment 2003-19-08...................  Amendment 39-13311.
------------------------------------------------------------------------

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-
400F, 747SR, and 747SP series airplanes; certificated in any 
category; line numbers 1 through 1307 inclusive.

Unsafe Condition

    (d) This AD results from reports of cracking in areas required 
to be inspected by the superseded ADs identified in Table 1 of this 
AD. We are issuing this AD to prevent fatigue cracking of the body 
station (BS) 2598 bulkhead structure, which could result in 
inability of the structure to carry horizontal stabilizer flight 
loads, and reduced controllability of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within

[[Page 60747]]

the compliance times specified, unless the actions have already been 
done.

Restatement of AD 2001-14-07

Repetitive High Frequency Eddy Current (HFEC) Inspections

    (f) Before the accumulation of 10,000 total flight cycles, or 
within 1,000 flight cycles after August 16, 2001 (the effective date 
of AD 2001-14-07), whichever occurs later: Do an open-hole HFEC 
inspection to find cracking of the bulkhead frame support under the 
hinge support fittings of the horizontal stabilizer on the left and 
right sides at BS 2598, in accordance with Figure 2 of the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2449, 
Revision 1, dated May 24, 2001; or Revision 2, dated March 14, 2002. 
Repeat the inspection after that at intervals not to exceed 3,000 
flight cycles. Inspections accomplished before August 16, 2001, per 
Boeing Alert Service Bulletin 747-53A2449, dated June 8, 2000, are 
considered acceptable for compliance with the applicable inspection 
specified in this paragraph.

Repair

    (g) If any cracking is found during any inspection required by 
paragraph (f) of this AD, before further flight, repair in 
accordance with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA, or using a method approved in 
accordance with paragraph (n)(5) of this AD.

Restatement of Certain Requirements of AD 2001-15-03

Repetitive Inspections

    (h) Do a surface HFEC inspection of the forward and aft inner 
chords, the frame support, and the splice fitting of the forward 
inner chord of the upper corner of the station 2598 bulkhead to find 
cracking, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2427, Revision 2, dated October 
5, 2000; or Revision 3, dated September 27, 2001; at the latest of 
the times specified in paragraphs (h)(1) and (h)(2) of this AD, as 
applicable. Repeat the inspection after that at intervals not to 
exceed 1,500 flight cycles.
    (1) For airplanes having line numbers 1 through 1241 inclusive:
    (i) Before the accumulation of 6,000 total flight cycles.
    (ii) Within 500 flight cycles after August 28, 2001 (the 
effective date of AD 2001-15-03).
    (iii) For airplanes inspected before August 28, 2001, in 
accordance with Boeing Alert Service Bulletin 747-53A2427, dated 
December 17, 1998 (including inspections of the splice fitting), or 
Revision 1, dated October 28, 1999: Within 1,500 flight cycles after 
accomplishment of the last inspection done in accordance with the 
original service bulletin or Revision 1, as applicable.
    (2) For airplanes having line numbers 1242 through 1307 
inclusive:
    (i) Before the accumulation of 16,000 total flight cycles.
    (ii) Within 500 flight cycles after August 28, 2001.
    (iii) For airplanes inspected before August 28, 2001, in 
accordance with Boeing Alert Service Bulletin 747-53A2427, dated 
December 17, 1998 (including inspections of the splice fitting), or 
Revision 1, dated October 28, 1999: Within 1,500 flight cycles after 
accomplishment of the last inspection done in accordance with the 
original service bulletin or Revision 1, as applicable.

Repair

    (i) If any cracking is found during the inspections required by 
paragraph (h) of this AD, before further flight, repair in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2427, Revision 2, dated October 5, 2000; or 
Revision 3, dated September 27, 2001; except where the alert service 
bulletin specifies that the manufacturer may be contacted for 
disposition of certain repair conditions, before further flight, 
repair in accordance with a method approved by the Manager, Seattle 
ACO, or using a method approved in accordance with paragraph (n)(5) 
of this AD.

Restatement of AD 2003-19-08

Repetitive Inspections

    (j) Before the accumulation of 10,000 total flight cycles, or 
within 1,000 flight cycles after October 27, 2003 (the effective 
date of AD 2003-19-08), whichever is later: Do a detailed inspection 
of the body station 2598 bulkhead for discrepancies (cracking, 
elongated fastener holes) of the areas specified in paragraphs 
(j)(1) and (j)(2) of this AD, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2467, dated 
July 26, 2001; or Revision 1, dated April 28, 2005. Repeat the 
inspections after that at intervals not to exceed 3,000 flight 
cycles.
    (1) The lower aft inner chords.
    (2) The upper aft outer chords, and the diagonal brace 
attachment fittings, flanges, and rods.

    Note 1: For the purposes of this AD, a detailed inspection is 
``an intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirrors magnifying lenses, etc. may be necessary. Surface cleaning 
and elaborate procedures may be required.''

Repair

    (k) If any discrepancy is found during any inspection required 
by paragraph (j) of this AD: Before further flight, repair in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2467, dated July 26, 2001; or Revision 1, 
dated April 28, 2005. If any discrepancy is found and the service 
bulletin specifies to contact Boeing for appropriate action: Before 
further flight, repair in accordance with a method approved by the 
Manager, Seattle ACO, or using a method approved in accordance with 
paragraph (n)(5) of this AD.

New Requirements of This AD

Modification

    (l) Before the accumulation of 20,000 total flight cycles, or 
within 48 months after the effective date of this AD, whichever 
occurs later: Modify the bulkhead by doing all applicable actions 
including surface and open-hole HFEC inspections for cracking of the 
upper forward inner chord, aft inner chord, upper splice fitting, 
and frame support fitting, as specified in the Accomplishment 
Instructions of Boeing Service Bulletin 747-53-2473, dated March 24, 
2005. Repair any cracks before further flight in accordance with the 
service bulletin. Where the service bulletin specifies that the 
manufacturer may be contacted for disposition of certain repair 
conditions: Before further flight, repair the cracks using a method 
approved in accordance with the procedures specified in paragraph 
(n) or (n)(5) of this AD. Accomplishment of the modification 
terminates the repetitive inspections required by paragraphs (f), 
(h), and (j)(1) of this AD.

Inspection

    (m) Within 20,000 flight cycles after the modification required 
by paragraph (l) of this AD, inspect the body station 2598 bulkhead 
for cracks, and repair any cracks before further flight, in 
accordance with a method approved by the Manager, Seattle ACO.

Alternative Methods of Compliance (AMOCs)

    (n)(1) The Manager, Seattle ACO, has the authority to approve 
AMOCs for this AD, if requested in accordance with the procedures 
found in 14 CFR 39.19.
    (2) AMOCs approved previously according to AD 2000-08-21, 
amendment 39-11707, and AD 2001-15-03 are approved as AMOCs for the 
corresponding requirements of paragraphs (h) and (i) of this AD. (AD 
2000-08-21 was superseded by AD 2001-15-03.)
    (3) AMOCs approved previously according to AD 2001-14-07 are 
approved as AMOCs for the corresponding requirements of paragraphs 
(f) and (g) of this AD.
    (4) AMOCs approved previously according to AD 2003-19-08 are 
approved as AMOCs for the corresponding requirements of paragraphs 
(j) and (k) of this AD.
    (5) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Seattle ACO, to make those findings. For a repair 
method to be approved, the repair must meet the certification basis 
of the airplane, and the approval must specifically refer to this 
AD.

    Issued in Renton, Washington, on September 28, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-20882 Filed 10-18-05; 8:45 am]
BILLING CODE 4910-13-P