[Federal Register Volume 70, Number 68 (Monday, April 11, 2005)]
[Proposed Rules]
[Pages 18327-18332]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-7154]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20879; Directorate Identifier 2004-NM-55-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, -100B, 100B SUD, 
-200B, and -300 Series Airplanes; and Model 747SP and 747SR Series 
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 adopt a new airworthiness directive (AD) 
for certain Boeing Model 747-100, -100B, 100B SUD, -200B, and -300 
series airplanes; and Model 747SP and 747SR series airplanes. This 
proposed AD would replace certain requirements of an existing AD. This 
proposed AD would require repetitive inspections to detect cracks in 
various areas of the upper deck floor beams, and repair if necessary. 
This proposed AD is prompted by the results of fatigue testing that 
revealed severed upper chords of the upper deck floor beams due to 
fatigue cracking. We are proposing this AD to detect and correct 
cracking in the upper chords of the upper deck floor beams. Undetected 
cracking could result in large deflection or deformation of the upper 
deck floor beams, resulting in damage to wire bundles and control 
cables for the flight control system, and reduced controllability of 
the airplane. Multiple adjacent severed floor beams could result in 
rapid decompression of the airplane.

DATES: We must receive comments on this proposed AD by May 26, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     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.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 
98124-2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street SW., Room PL-401, 
on the plaza level of the Nassif Building, Washington, DC. This docket 
number is FAA-2005-20879; the directorate identifier for this docket is 
2004-NM-55-AD.

FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6437; 
fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-20879; 
Directorate Identifier 2004-NM-55-AD'' in the subject line 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 submitted 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 website, 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 DOT's complete Privacy Act

[[Page 18328]]

Statement in the Federal Register published on April 11, 2000 (65 FR 
19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket 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 (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 DMS 
receives them.

Discussion

    On May 14, 2002, the FAA issued AD 2002-10-10, amendment 39-12756 
(67 FR 36081, May 23, 2002), applicable to certain Boeing Model 747 
series airplanes. That AD superseded AD 93-08-12, amendment 39-8559 (58 
FR 27927, May 12, 1993), to require repetitive inspections to detect 
cracks in various areas of the fuselage internal structure, and repair 
if necessary. AD 2002-10-10 was prompted by the results of fatigue 
testing that revealed severed upper chords of the upper deck floor 
beams due to fatigue cracking. The requirements of that AD are intended 
to prevent loss of the structural integrity of the fuselage, which 
could result in rapid depressurization of the airplane.
    Since the issuance of 2002-10-10 AD we have received a report 
indicating that cracking has been found in areas not included in the 
previous releases of Boeing Service Bulletin 747-53A2349. (Revision 1 
of that service bulletin, dated October 12, 2000, was cited as the 
appropriate source of service information for accomplishing certain 
actions required by AD 2002-10-10.) One of these areas is the upper 
chords of the upper deck floor beams. Cracking in these chords can 
cause large deflection or deformation of the floor, fuselage skin, 
frames, and stringers. Wire bundles and control cables are routed 
through cutouts in the upper deck floor beams. Deflection or 
deformation of the floor beams could result in damage to wire bundles 
and control cables for the flight control system, and reduced 
controllability of the airplane. Multiple adjacent severed floor beams 
could result in rapid decompression of the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2452, dated 
April 3, 2003. The inspections in this service bulletin were previously 
included in Boeing Alert Service Bulletin 747-53A2349, Revision 1. 
Boeing Alert Service Bulletin 747-53A2452 reduces the threshold for 
high frequency eddy current (HFEC) inspections of Area 1, the upper 
deck floor beams, from 28,000 to 22,000 total flight cycles. The 
threshold is being reduced because of the critical nature of the header 
floor beams that reinforce the upper deck floor stairway cutouts. 
Repetitive inspections have also been included for a new area, Area 3, 
which was not included in Boeing Alert Service Bulletin 747-53A2349, 
Revision 1. The Area 3 inspections are included to address a location 
where cracking was found on Boeing's 747SR fatigue test airplane.
    Boeing Alert Service Bulletin 747-53A2452 includes procedures for:
     Doing repetitive open-hole HFEC inspections for cracking 
of the floor panel attachment fastener holes in the upper chords.
     Modifying the clipnuts for the floor panel attachment 
fasteners.
     Doing repetitive surface HFEC inspections for cracking of 
the forward and aft horizontal flanges of the upper chords.
     Repairing cracking.
     Repetitively inspecting repaired areas.
    The alert service bulletin recommends that any repair be done 
before further flight in accordance with the alert service bulletin or 
instructions from Boeing. The alert service bulletin also indicates 
that Boeing should be contacted for a post-repair inspection plan if 
any repair is different from what is specified in the service bulletin.
    Figure 1 of the alert service bulletin recommends the following 
thresholds and repetitive intervals for accomplishing the actions 
specified in the alert service bulletin.

              Compliance Times for Area 1 in Figure 1 of Boeing Alert Service Bulletin 747-53A2452
----------------------------------------------------------------------------------------------------------------
                                         Initial threshold in                             Related investigative/
               Actions                   flight cycles (FCs)       Inspection results       corrective actions
----------------------------------------------------------------------------------------------------------------
Open-hole HFEC inspection of fastener  22,000 total FCs; 1,000  No cracks..............  Repetitive inspection
 holes at the upper chord of the        FCs after service       .......................   at 3,000 FCs.
 upper deck floor beams.                bulletin issuance; or   Cracks found...........  Repair crack before
                                        3,000 FCs after the                               further flight;
                                        most recent visual                                subsequent inspection
                                        inspection of Area 1;                             5,000-15,000 FCs;
                                        whichever is latest.                              repetitive inspection
                                                                                          at 3,000 FCs.
Oversize fastener holes for floor      10,000 FCs after         Not applicable.........  Repetitive inspection
 panel attachment.                      oversizing the holes.                             at 3,000 FCs.
Surface HFEC inspection of the         22,000 total FCs; 1,000  No cracks..............  Repetitive inspection
 horizontal flanges of the upper deck   FCs after service       Cracks found...........   at 750 FCs.
 floor beams.                           bulletin issuance; or                            Repair crack before
                                        3,000 FCs after the                               further flight;
                                        most recent visual                                subsequent inspection
                                        inspection of Area 1;                             5,000-15,000 FCs;
                                        whichever is latest.                              repetitive inspection
                                                                                          at 3,000 FCs.
----------------------------------------------------------------------------------------------------------------


              Compliance Times for Area 2 in Figure 1 of Boeing Alert Service Bulletin 747-53A2452
----------------------------------------------------------------------------------------------------------------
                                         Initial threshold in                             Related investigative/
               Actions                   flight cycles (FCs)       Inspection results       corrective actions
----------------------------------------------------------------------------------------------------------------
Open-hole HFEC inspection of fastener  28,000 total FCs; 3,000  No cracks..............  Repetitive inspection
 holes at the upper chord of the        FCs after the most      .......................   at 6,000 FCs.
 upper deck floor beams.                recent visual           Cracks found...........  Repair crack before
                                        inspection of Area 1;                             further flight;
                                        whichever is latest.                              subsequent inspection
                                                                                          5,000-15,000 FCs;
                                                                                          repetitive inspection
                                                                                          at 3,000 FCs.

[[Page 18329]]

 
Oversize fastener holes for floor      10,000 FCs after         Not applicable.........  Repetitive inspection
 panel attachment.                      oversizing the holes.                             at 6,000 FCs.
Surface HFEC inspection of the         22,000 total FCs; 3,000  No cracks..............  Repetitive inspection
 horizontal flanges of the upper deck   FCs after the most      Cracks found...........   at 2,000 FCs.
 floor beams.                           recent visual                                    Repair crack before
                                        inspection of Area 1;                             further flight;
                                        whichever is latest.                              subsequent inspection
                                                                                          5,000-15,000 FCs;
                                                                                          repetitive inspection
                                                                                          at 3,000 FCs.
----------------------------------------------------------------------------------------------------------------


              Compliance Times for Area 3 in Figure 1 of Boeing Alert Service Bulletin 747-53A2452
----------------------------------------------------------------------------------------------------------------
                                         Initial threshold in                             Related investigative/
               Actions                   flight cycles (FCs)       Inspection results       corrective actions
----------------------------------------------------------------------------------------------------------------
Open-hole HFEC inspection of station   22,000 total FCs; 1,000  No cracks..............  Repetitive inspection
 440 floor beam upper chord and         FCs after service       .......................   at 3,000 FCs.
 gusset.                                bulletin issuance; or   Cracks found...........  Repair crack before
                                        3,000 FCs after the                               further flight.
                                        most recent visual                                (Repetitive inspection
                                        inspection in Area 1;                             interval not defined.)
                                        whichever is latest.
----------------------------------------------------------------------------------------------------------------

    We have also reviewed Boeing Service Bulletin 747-53A2349, Revision 
2, dated April 3, 2003. This service bulletin describes procedures for 
repetitive internal detailed visual inspections for cracking of the 
upper deck floor beams, as well as certain other areas of the fuselage 
internal structure. For airplanes on which any cracking is found, the 
service bulletin references the Boeing 747 Structural Repair Manual 
(SRM) for repair instructions. For airplanes on which the damage is 
beyond the limits specified in the SRM, the service bulletin specifies 
contacting Boeing for repair data.

Compliance Times Specified in Previous Revision of Service Information

    Paragraph (i) of the proposed AD specifies to repeat the applicable 
inspection at the times specified in Sheet 7, Figure 2, of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2349, Revision 1, dated October 12, 2000. For the area at station 
380, between buttock lines (BL) 40 and 76, left and right sides, the 
service bulletin specifies that the open-hole and upper and lower 
surface HFEC inspections should be repeated every 3,000 flight cycles; 
and that the surface HFEC from below should be repeated every 750 
flight cycles. For the area at station 380, between left BL 40 and 
right BL 40, and all other affected floor beam locations, the service 
bulletin specifies that the open-hole and upper and lower surface HFEC 
inspections should be repeated every 6,000 flight cycles; and that the 
surface HFEC from below should be repeated every 2,000 flight cycles.

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 this same type design. Therefore, we are proposing this AD, which 
would require repetitive inspections to detect cracks in various areas 
of the upper deck floor beams, and repair if necessary. The proposed AD 
would require you to use the service information described previously 
to perform these actions, except as discussed under ``Differences 
Between the Proposed AD and the Service Information.''

Other Related Rulemaking

    Operators should note that we plan to issue a separate AD 
rulemaking action (reference Directorate Identifier 2003-NM-229-AD) to 
address the identified unsafe condition as it relates to various areas 
of the fuselage internal structure, excluding the upper deck floor 
beams. Therefore, we will propose to include all requirements from AD 
2002-10-10 that relate to various areas of the fuselage internal 
structure, excluding the upper deck floor beams, in that separate AD 
rulemaking action. Additionally, the new procedures described in Boeing 
Service Bulletin 747-53A2349, Revision 2, for various internal and 
external detailed visual inspections of fuselage internal structure, 
excluding those related to the upper deck floor beams, are included in 
that separate AD rulemaking action.

Differences Between the Proposed AD and the Service Information

    The compliance times for the HFEC inspections in the proposed AD 
are dependent upon what type of inspections, if any, have been 
accomplished previously. Boeing Alert Service Bulletin 747-53A2452 does 
not base the compliance times on what type of inspection was 
accomplished previously.
    Operators should note that, although Boeing Alert Service Bulletin 
747-53A2452, dated April 3, 2003, specifies that you may contact the 
manufacturer for instructions on how to repair certain conditions, this 
proposed AD would require you to repair those conditions in one of the 
following ways:
     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 Delegation Option Authorization Organization whom we 
have authorized to make those findings.
    Figure 2, sheet 7, of Boeing Alert Service Bulletin 747-53A2349, 
Revision 1, dated October 12, 2000, specifies that if a surface HFEC 
inspection of the upper deck floor beams was performed from below the 
floor beams, the repetitive inspection intervals would be 2,000 flight 
cycles. Figure 1 of Boeing Alert Service Bulletin 747-53A2452, dated 
April 3, 2003, specifies that the repetitive inspection intervals would 
be 750 flight cycles. This proposed AD would require the next surface 
HFEC inspection within 2,000 flight cycles from the most recent 
inspection, or within 750 flight cycles after the effective date of the 
AD, whichever is

[[Page 18330]]

first. We have concluded that, for operators that have scheduled 
repetitive inspections at intervals not to exceed 2,000 flight cycles, 
an immediate reduction to intervals not to exceed 750 flight cycles 
could unnecessarily ground airplanes. The compliance time for the next 
surface HFEC inspection in the proposed AD would allow operators to 
transition from repetitive inspection intervals not to exceed 2,000 
flight cycles to repetitive inspection intervals not to exceed 750 
flight cycles.
    Figure 2, sheet 7, of Boeing Alert Service Bulletin 747-53A2349, 
Revision 1, also specifies that, if a surface HFEC inspection of the 
upper deck floor beams was most recently performed from above and below 
the floor beams, or if an open-hole HFEC inspection of the floor beams 
was performed, the repetitive inspection intervals would be 6,000 
flight cycles. Figure 1 of Boeing Alert Service Bulletin 747-53A2452 
specifies that the repetitive inspection intervals would be 3,000 
flight cycles. This proposed AD would require that the next HFEC 
inspection be performed within 6,000 flight cycles from the most recent 
inspection, or within 3,000 flight cycles after the effective date of 
the AD, whichever is first. We have concluded that, for operators that 
have scheduled repetitive inspections at intervals of 6,000 flight 
cycles, a reduction to intervals of 3,000 flight cycles could 
unnecessarily ground airplanes. The compliance time in the proposed AD 
for the next HFEC inspection above and below the floor beams, or the 
next open-hole HFEC inspection, would allow operators to transition 
from repetitive inspection intervals of 6,000 flight cycles to 
repetitive inspection intervals of 3,000 flight cycles.
    Some of the compliance times in Figure 1 of Boeing Alert Service 
Bulletin 747-53A2452 are stated in terms of 1,000 flight cycles after 
the date on the service bulletin. This proposed AD would require 
accomplishment within 1,000 flight cycles after the effective date of 
the AD.

Costs of Compliance

    There are about 489 airplanes of the affected design worldwide. 
This proposed AD would affect about 155 airplanes of U.S. registry.
    The actions for the upper deck floor beams that are required by AD 
93-08-12, and retained in AD 2002-10-10 and this proposed AD, take 
about 150 work hours per airplane, at an average labor rate of $65 per 
work hour. Based on these figures, the estimated costs of these 
currently required actions are $9,750 per airplane, per inspection 
cycle.
    The inspections of the upper deck floor beams that are required by 
AD 2002-10-10 and retained in this proposed AD take about 255 work 
hours per airplane, at an average labor rate of $65 per work hour. 
Based on these figures, the estimated cost of these currently required 
inspections is $16,575 per airplane, per inspection cycle.
    The new proposed inspections would take about 155 work hours per 
airplane, at an average labor rate of $65 per work hour. Based on these 
figures, the estimated cost of the new actions specified in this 
proposed AD for U.S. operators is $1,561,625 or $10,075 per airplane, 
per inspection cycle.

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. 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 FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Boeing: Docket No. FAA-2005-20879; Directorate Identifier 2004-NM-
55-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by May 26, 2005.

Affected ADs

    (b) Related to AD 2002-10-10, amendment 39-12756 (67 FR 36081, 
May 23, 2002).

Applicability

    (c) This AD applies to Boeing Model 747-100, -100B, 100B SUD, -
200B, and -300 series airplanes; and Model 747SP and 747SR series 
airplanes; certificated in any category; identified in Boeing Alert 
Service Bulletin 747-53A2452, dated April 3, 2003.

Unsafe Condition

    (d) This AD was prompted by the results of fatigue testing by 
the manufacturer that revealed severed upper chords of the upper 
deck floor beams due to fatigue cracking. We are issuing this AD to 
detect and correct cracking in the upper chords of the upper deck 
floor beams. Undetected cracking could result in large deflection or 
deformation of the upper deck floor beams, resulting in damage to 
wire bundles and control cables for the flight control system, and 
reduced controllability of the airplane. Multiple adjacent severed 
floor beams could result in rapid decompression of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

    Note 1: Paragraphs (f) and (g) of this AD restate the 
requirements of paragraphs (a) and (b) of AD 2002-10-10. As allowed 
by the phrase, ``unless accomplished previously,'' if those 
requirements of AD 2002-10-10 have already been accomplished, this 
AD does not require that those actions be repeated.


[[Page 18331]]



Inspection

    (f) Before the accumulation of 22,000 total flight cycles, or 
within 1,000 flight cycles after June 11, 1993 (the effective date 
of AD 93-08-12, amendment 39-8559), whichever occurs later, unless 
accomplished previously within the last 2,000 flight cycles; and 
thereafter at intervals not to exceed 3,000 flight cycles: Do a 
detailed inspection to detect cracks in the upper deck floor beams 
in Sections 41 and 42, in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 747-53-2349, dated June 27, 
1991; Boeing Alert Service Bulletin 747-53A2349, Revision 1, dated 
October 12, 2000; or Boeing Service Bulletin 747-53A2349, Revision 
2, dated April 3, 2003. After the effective date of this AD, only 
Boeing Service Bulletin 747-53A2349, Revision 2, dated April 3, 
2003, may be used. Continue doing the inspections required by this 
paragraph until the inspections required by paragraph (h) or (l) of 
this AD are accomplished.

Repair

    (g) Before further flight, repair any cracking detected during 
the inspections done in accordance with paragraph (f) of this AD, 
according to a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA; or according to data meeting the 
certification basis of the airplane approved a Boeing Company 
Designated Engineering Representative (DER) who has been authorized 
by the Manager, Seattle ACO, to make such findings; or by an 
Authorized Representative (AR) for the Boeing Delegation Option 
Authorization (DOA) Organization who has been authorized by the 
Manager, Seattle ACO, to make those findings. For a repair method to 
be approved, the approval must specifically reference this AD.

    Note 2: Paragraphs (h), (i), (j), and (k), of this AD restate 
the requirements of paragraphs (d), (e), (f), and (g), of AD 2002-
10-10. As allowed by the phrase, ``unless accomplished previously,'' 
if those requirements of AD 2002-10-10 have already been 
accomplished, this AD does not require that those actions be 
repeated.

Inspections

    (h) Before the accumulation of 22,000 total flight cycles, or 
within 3,000 flight cycles after doing the most recent inspection 
required by paragraph (f) of this AD, whichever occurs later: Do a 
detailed inspection to find cracking in the areas specified in 
paragraph (h)(1) or (h)(2), as applicable, in accordance with Figure 
2 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 747-53A2349, Revision 1, dated October 12, 2000; or Boeing 
Service Bulletin 747-53-2349, Revision 2, dated April 3, 2003. After 
the effective date of this AD, only Boeing Alert Service Bulletin 
747-53A2349, Revision 2, may be used. Repeat the inspection 
thereafter at intervals not to exceed 3,000 flight cycles. Continue 
doing the inspection required by this paragraph until the initial 
inspection required by paragraph (l) of this AD is accomplished. 
Accomplishment of the inspection in this paragraph terminates the 
inspections required by paragraph (f) of this AD.
    (1) For Groups 1, 2, 4, and 5 airplanes: Do the inspections of 
Area 1 (sections 41 and 42 upper deck floor beams), including 
existing repairs and modifications.
    (2) For Group 3 airplanes: Do the inspections of Area 1 
(sections 41, 42, and 44 upper deck floor beams from body stations 
380 through 1100 inclusive), including existing repairs and 
modifications.

    Note 3: 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.''

    (i) Before the accumulation of 28,000 total flight cycles, or 
within 3,000 flight cycles after doing the most recent inspection 
required by paragraph (f) of this AD, whichever occurs later: Do a 
high frequency eddy current (HFEC) inspection to find cracking of 
the open holes in the horizontal flanges of the upper chord of the 
upper deck floor beams in the areas specified in paragraph (i)(1) or 
(i)(2) of this AD, as applicable, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2349, Revision 1, dated October 12, 2000. Do the inspection in 
accordance with the ``Inspection Alternatives'' as specified in 
Sheet 7 of Figure 2 of the Accomplishment Instructions of the 
service bulletin. Repeat the applicable inspection at the times 
specified in the ``Repeat Inspection Intervals'' in Sheet 7 of 
Figure 2 of the Accomplishment Instructions of the service bulletin. 
After the effective date of this AD, Boeing Alert Service Bulletin 
747-53A2452, dated April 3, 2003, must be used to perform the 
inspections required by this paragraph. Repeat the inspections until 
the requirements of paragraph (m) of this AD are accomplished.
    (1) For Group 1, 2, 4, and 5 airplanes: Do the inspections at 
the applicable locations (BS 380 through BS 780 inclusive for Groups 
1, 2, and 4, BS 380 through BS 860 inclusive for Group 5) as 
specified in Sheet 7 of Figure 2.
    (2) For Group 3 airplanes: Do the inspections as specified in 
Sheet 7 of Figure 2, at the upper deck floor beams from BS 380 
through BS 1100 inclusive.

    Note 4: HFEC inspections of the left and right sides of the 
upper deck floor beam at body station 380, between buttock lines 40 
and 76, done in accordance with AD 2000-04-17, are considered 
acceptable for compliance with the applicable inspections specified 
in paragraph (i) of this AD.

Adjustments to Compliance Time: Cabin Differential Pressure

    (j) For the purposes of calculating the compliance threshold and 
repetitive interval for the actions required by paragraphs (h) and 
(i) of this AD: For Area 1 only, the number of flight cycles in 
which cabin differential pressure is at 2.0 pounds per square inch 
(psi) or less need not be counted when determining the number of 
flight cycles that have occurred on the airplane, provided that 
flight cycles with momentary spikes in cabin differential pressure 
above 2.0 psi are included as full pressure cycles. For this 
provision to apply, all cabin pressure records must be maintained 
for each airplane: No fleet-averaging of cabin pressure is allowed.

Repair

    (k) Before further flight, repair any cracking found during the 
inspections done in accordance with paragraphs (h) and (i) of this 
AD, in accordance with Boeing Alert Service Bulletin 747-53A2349, 
Revision 1, dated October 12, 2000. Where the service bulletin 
specifies to contact Boeing for repair instructions, repair 
according to a method approved by the Manager, Seattle ACO; or 
according to data meeting the type certification basis of the 
airplane approved by a Boeing Company DER who has been authorized by 
the Manager, Seattle ACO, to make such findings; or by an AR for the 
Boeing DOA who has been authorized by the Manager, Seattle ACO, to 
make those findings. For a repair method to be approved, the 
approval must specifically reference this AD.

New Requirements of This AD

Detailed Inspection

    (l) Before the accumulation of 22,000 total flight cycles, or 
within 3,000 flight cycles after the most recent inspection required 
by paragraph (f) or (h) of this AD, whichever is later: Do a 
detailed inspection for cracking of the horizontal flanges of the 
upper chord of the upper deck floor beams. Do the inspection in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-53A2349, Revision 2, dated April 3, 2003. Repeat the 
inspection thereafter at intervals not to exceed 3,000 flight 
cycles. Doing the initial inspection required by this paragraph 
terminates the inspections required by paragraphs (f) and (h) of 
this AD.

High Frequency Eddy Current (HFEC) Inspection

    (m) Do a HFEC inspection for cracking of the horizontal flanges 
of the upper chord of the upper deck floor beams, in accordance with 
the Accomplishment Instructions of Boeing Service Bulletin 747-
53A2452, dated April 3, 2003, at the applicable time specified in 
paragraph (m)(1), (m)(2), (m)(3), or (m)(4) of this AD. Areas 1, 2, 
and 3, as specified in paragraphs (m) and (n) of this AD, are 
defined in the service bulletin. Accomplishment of this inspection 
terminates the inspections required by paragraph (i) of this AD.
    (1) For airplanes that have not been inspected in accordance 
with the requirements of paragraph (f), (h), or (i) of this AD:
    (i) For Area 1: Before the accumulation of 22,000 total flight 
cycles, or within 1,000 flight cycles after the effective date of 
this AD, whichever is later.
    (ii) For Area 2: Before the accumulation of 28,000 total flight 
cycles.

[[Page 18332]]

    (iii) For Area 3: Before the accumulation of 22,000 total flight 
cycles, or within 1,000 flight cycles after the effective date of 
this AD, whichever is later.
    (2) For airplanes that have been inspected in accordance with 
the requirements of paragraph (f) or (h) of this AD, but not the 
requirements of paragraph (i) of this AD:
    (i) For Area 1: Before the accumulation of 22,000 total flight 
cycles, or within 3,000 flight cycles after the most recent 
inspection required by paragraph (f) or (h) of this AD, whichever is 
later.
    (ii) For Area 2: Before the accumulation of 28,000 total flight 
cycles, or within 3,000 flight cycles after the most recent 
inspection required by paragraph (f) or (h) of this AD, whichever is 
later.
    (iii) For Area 3: Before the accumulation of 22,000 total flight 
cycles, or within 3,000 flight cycles after the most recent 
inspection required by paragraph (f) or (h) of this AD, whichever is 
later.
    (3) For airplanes on which a surface HFEC inspection of the 
horizontal flanges of the upper chord of the upper deck floor beams, 
as required by paragraph (i) of this AD, was accomplished, and the 
surface HFEC inspection was accomplished from below the upper deck 
floor beams as specified by Figure 2, circle note 2c., of Boeing 
Alert Service Bulletin 747-53A2349, Revision 1:
    (i) For Area 1: At the later of the times specified in 
paragraphs (m)(3)(i)(A) and (m)(3)(i)(B) of this AD.
    (A) Before the accumulation of 22,000 total flight cycles.
    (B) Within 2,000 flight cycles after the most recent inspection 
required by paragraph (i) of this AD, or 750 flight cycles after the 
effective date of this AD, whichever is first.
    (ii) For Area 2: Before the accumulation of 28,000 total flight 
cycles, or within 2,000 flight cycles after the most recent 
inspection required by paragraph (i) of this AD, whichever is later.
    (iii) For Area 3: Before the accumulation of 22,000 total flight 
cycles, or within 3,000 flight cycles after the most recent 
inspection required by paragraph (f) or (h) of this AD, whichever is 
later.
    (4) For airplanes on which either a surface or open-hole HFEC 
inspection of the horizontal flanges of the upper chord of the upper 
deck floor beams, as required by paragraph (i) of this AD has been 
accomplished, and the surface HFEC inspection was accomplished from 
above and below the upper deck floor beams, as specified by Figure 
2, circle note 2b., of Boeing Alert Service Bulletin 747-53A2349, 
Revision 1:
    (i) For Area 1: At the later of the times specified in 
paragraphs (m)(4)(i)(A) and (m)(4)(ii)(B) of this AD.
    (A) Before the accumulation of 22,000 total flight cycles.
    (B) Within 6,000 flight cycles after the most recent inspection 
required by paragraph (i) of this AD, or within 3,000 flight cycles 
after the effective date of this AD whichever is first.
    (ii) For Area 2: Before the accumulation of 28,000 total flight 
cycles, or within 6,000 flight cycles after the most recent 
inspection required by paragraph (i) of this AD, whichever is later.
    (iii) For Area 3: Before the accumulation of 22,000 total flight 
cycles, or within 3,000 flight cycles after the most recent 
inspection required by paragraph (f) or (h) of this AD, whichever is 
latest.

Repetitive Inspections

    (n) Except as required by paragraphs (o), (p), and (q) of this 
AD, repeat the inspections required by paragraph (m) of this AD at 
intervals not to exceed those specified in paragraphs (n)(1), 
(n)(2), and (n)(3) of this AD:
    (1) For Area 1: 3,000 flight cycles if an open-hole HFEC 
inspection was accomplished, or 750 flight cycles if a surface HFEC 
inspection was accomplished.
    (2) For Area 2: 6,000 flight cycles if an open-hole HFEC 
inspection was accomplished, or 2,000 flight cycles if a surface 
HFEC inspection was accomplished.
    (3) For Area 3: 3,000 flight cycles.

Repair

    (o) Before further flight, repair any cracking found during any 
inspection required by paragraph (l), (m), or (n) of this AD in 
accordance with Boeing Alert Service Bulletin 747-53A2452, dated 
April 3, 2003. Repairs done in accordance with the service bulletin 
terminates the requirements of paragraphs (l), (m), and (n) of this 
AD for the repaired area only. Where the service bulletin specifies 
to contact Boeing for repair instructions, repair according to a 
method approved by the Manager, Seattle ACO; or according to data 
meeting the certification basis of the airplane approved by an AR 
for the Boeing DOA who has been authorized by the Manager, Seattle 
ACO, to make those findings. For a repair method to be approved, the 
approval must specifically reference this AD.

After-Repair Inspections

    (p) At the applicable new inspection thresholds specified in 
Figure 1 of Boeing Alert Service Bulletin 747-53A2452, dated April 
3, 2003, perform the after-repair inspections for cracking in Areas 
1 and 2, as specified in the service bulletin. Where the service 
bulletin specifies a threshold after the date of the service 
bulletin, use that same threshold after the effective date of this 
AD. Perform the after-repair inspections by accomplishing all of the 
applicable actions specified in the alert service bulletin. Repair 
any cracking found during any inspection required by this paragraph, 
according to a method approved by the Manager, Seattle ACO; or 
according to data meeting the certification basis of the airplane 
approved by an AR for the Boeing DOA who has been authorized by the 
Manager, Seattle ACO, to make those findings. For a repair method to 
be approved by the Manager, Seattle ACO, as required by this 
paragraph, the approval letter must specifically reference this AD. 
Any cracking found during any inspection must be repaired before 
further flight. Repeat the inspections of Areas 1 and 2 thereafter 
at intervals not to exceed 3,000 flight cycles.

Optional Preventative Modification

    (q) If no cracking was found during the open-hole HFEC 
inspections required by paragraph (m) or (n) of this AD, repairing 
or modifying Areas 1 and 2, as defined in Figure 1 of Boeing Alert 
Service Bulletin 747-53A2452, dated April 3, 2003, in accordance 
with the service bulletin, defers the repetitive inspections 
required by paragraph (n) of this AD, and establishes new inspection 
methods, thresholds, and repetitive inspection intervals for the 
repaired or modified area. The new inspection thresholds and 
intervals are specified in Figure 1 of the service bulletin. Where 
the service bulletin specifies a threshold after the date of the 
service bulletin, use that same threshold after the effective date 
of this AD.

Inspections Done Previously

    (r) Doing the inspections required by paragraphs (m) and (n) of 
this AD before the effective date of this AD, in accordance with the 
Accomplishment Instructions in Boeing Alert Service Bulletin 747-
53A2349, Revision 1, dated October 12, 2000, is acceptable for 
compliance with the corresponding actions required by this AD.

Alternative Methods of Compliance (AMOCs)

    (s)(1) The Manager, Seattle ACO, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19.
    (2) Alternative methods of compliance and FAA-approved repairs, 
approved previously in accordance with AD 2002-10-10 are approved as 
AMOCs for the corresponding actions required by this AD.

    Issued in Renton, Washington, on April 1, 2005.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-7154 Filed 4-8-05; 8:45 am]
BILLING CODE 4910-13-P