[Federal Register Volume 67, Number 100 (Thursday, May 23, 2002)]
[Rules and Regulations]
[Pages 36081-36085]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-12635]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-355-AD; Amendment 39-12756; AD 2002-10-10]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 747 series airplanes, that 
currently requires repetitive inspections to detect cracks in various 
areas of the fuselage internal structure, and repair, if necessary. 
This amendment adds new repetitive inspections for cracking of certain 
areas of the upper chord of the upper deck floor beams, and repair, if 
necessary. This amendment is prompted by the results of fatigue testing 
that revealed severed upper chords of the upper deck floor beams due to 
fatigue cracking. The actions specified by this AD are intended to 
prevent loss of the structural integrity of the fuselage, which could 
result in rapid depressurization of the airplane.

DATES: Effective June 27, 2002.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-53A2349, Revision 1, dated October 12, 2000, as listed in the 
regulations, is approved by the Director of the Federal Register as of 
June 27, 2002.
    The incorporation by reference of Boeing Service Bulletin 747-53-
2349, dated June 27, 1991, as listed in the regulations, was approved 
previously by

[[Page 36082]]

the Director of the Federal Register as of June 11, 1993 (58 FR 27927, 
May 12, 1993).

ADDRESSES: 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 Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 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: Rick Kawaguchi, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1153; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 93-08-12, 
amendment 39-8559 (58 FR 27927, May 12, 1993), which is applicable to 
certain Boeing Model 747 series airplanes, was published in the Federal 
Register on November 27, 2001 (66 FR 59180). The action proposed to 
continue to require repetitive inspections to detect cracks in various 
areas of the fuselage internal structure, and repair, if necessary. The 
action also proposed to add new repetitive inspections for cracking of 
certain areas of the upper chord of the upper deck floor beams, and 
repair, if necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Clarify Note 3

    Two commenters ask that Note 3 of the proposed rule be changed for 
clarification. The commenters note that the section titled 
``Differences Between Proposed AD and Revision 1 of the Alert Service 
Bulletin'' states that the proposed AD would not require the high 
frequency eddy current inspection of the left and right sides of the 
upper deck floor beam at body station 380 between buttock lines 40 and 
76 because it was mandated in AD 2000-04-17, amendment 39-11600 (65 FR 
10695, February 29, 2000). The commenters state that Note 3 addresses 
only inspections that were done before the effective date of this AD, 
not any subsequent inspections done per AD 2000-04-17.
    The FAA agrees that, for this area, the high frequency eddy current 
inspections required by AD 2000-04-17, done before AND after the 
effective date of this AD, meet the intent of this AD. Therefore, Note 
3 of this final rule has been changed for clarification.

Change Paragraph (d)(2)

    One commenter (the manufacturer) asks that paragraph (d)(2) of the 
proposed rule be changed for clarification. The commenter notes that 
the inspections for Group 3 airplanes are located in sections 41, 42, 
AND 44 upper deck floor beams.
    We agree with the commenter. The proposed rule specifies 
inspections of Area 1, and, as information only, included the sections 
in that area (sections 41 and 42 upper deck floor beams from body 
stations 380 through 1100 inclusive). However, for Group 3 airplanes, 
section 44 is also part of Area 1, so we have added that section to 
paragraph (d)(2) of this final rule for clarification.

Change Paragraph (d)

    One commenter asks that the inspection specified in paragraph (d) 
of the proposed rule be changed to include a provision for airplanes 
that have been modified to a stretched upper deck configuration. This 
modification involves installation of new upper deck floor beams from 
body stations 380 through 1100 inclusive. The commenter states that the 
initial inspection for these airplanes should not have to be done until 
22,000 flight cycles AFTER incorporation of the upper deck 
modification.
    We do not agree with the commenter. Due to the fact that these 
airplanes have many different configurations, the commenter must 
provide sufficient technical data justifying that the increased risk 
associated with extending the compliance time is insignificant. If such 
data are submitted, we will consider approving the commenter's request 
as an alternative method of compliance (AMOC), as provided in paragraph 
(h)(1) of this final rule. No change to the final rule is necessary in 
this regard.

Change Paragraph (a)

    One commenter asks that additional requirements be added following 
paragraph (d) of the proposed rule to require that, at 22,000 total 
flight cycles or 3,000 flight cycles after the last inspection required 
by AD 93-08-12, the next inspection of the locations described in 
paragraphs (a)(2) through (a)(7) of the proposed rule be done per 
Revision 1 of the service bulletin. The commenter also asks that, at 
25,000 total flight cycles or 3,000 flight cycles after the last 
inspection required by AD 93-08-12, the next inspection of the location 
described in paragraph (b) of the proposed rule be done per Revision 1 
of the service bulletin. The commenter states that this would terminate 
all inspections required by paragraphs (a)(1) through (a)(7) and 
paragraph (b) of the proposed rule. The commenter notes that Revision 1 
of the service bulletin adds improvements such as new access procedures 
to allow better inspections of Area 3, section 46, lower lobe frames, 
and Area 6, main entry door cutouts.
    We do not agree with the commenter. We have determined that the 
access procedures specified in the original issue of the service 
bulletin provide for adequate inspections. We also have determined that 
the improvements in Revision 1 of the service bulletin do not need to 
be mandated to meet the intent of the proposed rule. It should be noted 
that Revision 1 has been approved as an AMOC to AD 93-08-12. No change 
to the final rule is necessary in this regard.

Change Paragraph (h)(2)

    One commenter asks that paragraph (h)(2) of the proposed rule be 
changed to consider AMOCs approved previously in accordance with AD 93-
08-12 to be approved for compliance with paragraphs (a) and (b) of the 
proposed rule ONLY.
    We do not agree with the commenter. We have reviewed all existing 
AMOCs and have determined that continued approval of these AMOCs will 
not compromise the intent of the proposed rule. No change to the final 
rule is necessary in this regard.

Change Paragraph (g)

    One commenter asks that paragraph (g) of the proposed rule be 
changed to add a requirement to repair any cracking found during the 
inspections required by paragraphs (a) and (b) of the proposed rule, in 
addition to the inspections required by paragraphs (d) and (e), and to 
include any new paragraphs added.
    We do not agree with the commenter. Paragraph (c) of the proposed 
rule addresses the repairs for paragraphs (a) and (b) of the proposed 
rule. In addition, no new paragraphs will be added after paragraph (d) 
of the final rule, as specified in our response in the request to 
change paragraph (a), above. No change to the final rule is necessary 
in this regard.

Change Preamble

    One commenter asks that certain wording in the preamble of the

[[Page 36083]]

proposed rule be changed. The commenter states that the wording in the 
section titled ``Explanation of Relevant Service Information'' should 
be changed from ``eliminate the need for the existing inspections,'' to 
``replace the existing inspections.'' The commenter also asks that the 
wording in the section titled ``Explanation of Requirements of the 
Proposed Rule'' be changed from ``Since an unsafe condition has been 
identified,'' to ``Since a potential unsafe condition has been 
identified.''
    We acknowledge and agree with the commenter's remarks on the 
preamble of the proposed rule; however, the sections referred to are 
not restated in this final rule. Therefore, no change to the final rule 
is necessary in this regard.

Alternative Inspection

    One commenter asks that a detailed visual inspection from below the 
upper deck floor beams between body stations 1020 and 1100 be approved 
as an alternative inspection method to meet the detailed visual 
inspection requirements for Group 3 airplanes specified in the proposed 
rule. The commenter states that this alternative inspection method is 
specified in Note 1 of Step 1, Figure 2, of the Accomplishment 
Instructions of Revision 1 of the referenced service bulletin.
    We do not agree with the commenter. The note in Step 1, Figure 2, 
of the service bulletin is limited to floor beams between body stations 
260 and 330. We disagree that inspections from below will provide an 
equivalent level of safety for the floor beams located between body 
stations 1020 and 1100. However, if data are submitted that provide 
procedures for an alternative inspection program that will offer an 
acceptable level of safety, we would consider this under the provisions 
for an AMOC, as provided in paragraph (h)(1) of this final rule. No 
change to the final rule is necessary in this regard.

Explanation of Change to Final Rule

    Since the issuance of the proposed rule, the FAA has found that the 
identification of affected airplanes in the preamble of the proposed 
rule needs further clarification. Therefore, we have changed the 
preamble to specify ``certain Boeing Model 747 series airplanes,'' 
instead of listing out each model. This change is made for consistency 
with the effectivity of the service bulletin, which is listed in the 
applicability section within the final rule.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Interim Action

    This is considered to be interim action until similar action for 
Boeing Model 747-400 series airplanes and 747 freighter airplanes is 
identified, at which time the FAA may consider further rulemaking.

Cost Impact

    There are approximately 489 airplanes of the affected design in the 
worldwide fleet.
    The FAA estimates that 181 airplanes of U.S. registry are subject 
to the existing AD. The actions that are currently required by AD 93-
08-12 take approximately 1,746 work hours per airplane to accomplish, 
at an average labor rate of $60 per work hour. Based on these figures, 
the cost impact of the currently required actions is estimated to be 
$104,760 per airplane.
    We estimate that 155 airplanes of U.S. registry are subject to the 
new actions in this AD. The new inspections that are required by this 
AD action will take approximately 255 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of the requirements of this AD on U.S. 
operators is estimated to be $2,371,500, or $15,300 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

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.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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.


 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-8559 (58 FR 
27927, May 12, 1993), and by adding a new airworthiness directive (AD), 
amendment 39-12756, to read as follows:

2002-10-10  Boeing: Amendment 39-12756. Docket 2000-NM-355-AD. 
Supersedes AD 93-08-12, Amendment 39-8559.

    Applicability: Model 747 series airplanes, as listed in Boeing 
Service Bulletin 747-53-2349, dated June 27, 1991, or Boeing Alert 
Service Bulletin 747-53A2349, Revision 1, dated October 12, 2000; 
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 (h)(1) 
of this AD. The request should include an assessment of

[[Page 36084]]

the effect of the modification, alteration, or repair on the unsafe 
condition addressed by this AD; and, if the unsafe condition has not 
been eliminated, the request should include specific proposed 
actions to address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent loss of the structural integrity of the fuselage, 
which could result in rapid depressurization of the airplane, do the 
following:

Restatement of Requirements of AD 93-08-12

Repetitive Inspections

    (a) Prior to 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: Perform a 
detailed internal inspection to detect cracks in the areas of the 
fuselage internal structure specified in paragraphs (a)(1) through 
(a)(7) of this AD; in accordance with Boeing Service Bulletin 747-
53-2349, dated June 27, 1991.
    (1) Sections 41 and 42 upper deck floor beams.
    (2) Section 42 upper lobe frames.
    (3) Section 46 lower lobe frames.
    (4) Section 42 lower lobe frames.
    (5) Main entry door cutouts.
    (6) Section 41 body station 260, 340, and 400 bulkheads.
    (7) Main entry doors.
    (b) Prior to the accumulation of 25,000 total flight cycles, or 
within 1,000 flight cycles after June 11, 1993, whichever occurs 
later, unless accomplished previously within the last 2,000 flight 
cycles; and thereafter at intervals not to exceed 3,000 flight 
cycles: Perform a detailed internal inspection to detect cracks in 
the Section 46 upper lobe frames, in accordance with Boeing Service 
Bulletin 747-53-2349, dated June 27, 1991.

Repair

    (c) Prior to further flight, repair any cracks detected during 
the inspections done per paragraph (a) or (b) of this AD, per a 
method approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA; or per data meeting the type certification basis 
of the airplane approved by a Boeing Company Designated Engineering 
Representative (DER) 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 
approval letter must specifically reference this AD.

New Requirements of This AD

Repetitive Inspections

    (d) Before the accumulation of 22,000 total flight cycles, or 
within 3,000 flight cycles after doing the most recent inspection 
required by paragraph (a) of this AD, whichever occurs later: Do a 
detailed inspection to find cracking in the areas specified in 
paragraph (d)(1) or (d)(2) of this AD, as applicable, per Figure 2 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-53A2349, Revision 1, dated October 12, 2000. Repeat the 
inspection after that every 3,000 flight cycles. Doing this 
inspection terminates the inspections required by paragraph (a) of 
this AD in the area specified in paragraph (a)(1) of this AD only.
    (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 2: 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.''

    (e) Before the accumulation of 28,000 total flight cycles, or 
within 3,000 flight cycles after doing the most recent inspection 
required by paragraph (a) 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 each 
upper deck floor beam in the areas specified in paragraph (e)(1) or 
(e)(2) of this AD, as applicable, per the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2349, Revision 
1, dated October 12, 2000. Do the inspection per ``Inspection 
Alternatives,'' as specified in Sheet 7 of Figure 2 of the 
Accomplishment Instructions of the service bulletin. Repeat the 
applicable inspection according to the ``Repeat Inspection 
Intervals,'' specified in Sheet 7 of Figure 2 of the Accomplishment 
Instructions of the service bulletin.
    (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 3: 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 per AD 2000-04-17, amendment 39-11600, are considered 
acceptable for compliance with the applicable inspections specified 
in paragraph (e) of this AD.

Adjustments to Compliance Time: Cabin Differential Pressure

    (f) For the purposes of calculating the compliance threshold and 
repetitive interval for the actions required by paragraphs (d) and 
(e) 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

    (g) Before further flight, repair any cracking found during the 
inspections done per paragraphs (d) and (e) of this AD, according to 
Boeing Alert Service Bulletin 747-53A2349, Revision 1, dated October 
12, 2000. Where the service bulletin specifies to contact Boeing for 
repair instructions, 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 DER 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 approval letter must specifically reference this AD.

Alternative Methods of Compliance

    (h)(1) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle 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.
    (2) Alternative methods of compliance and FAA-approved repairs, 
approved previously in accordance with AD 93-08-12, amendment 39-
8559, are approved as alternative methods of compliance with this 
AD.

    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

    (i) Special flight permits may be issued in accordance with 
 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

    (j) Except as provided by paragraphs (c), (f), and (g) of this 
AD, the actions shall be done in accordance with Boeing Service 
Bulletin 747-53-2349, dated June 27, 1991; and Boeing Alert Service 
Bulletin 747-53A2349, Revision 1, dated October 12, 2000; as 
applicable.
    (1) The incorporation by reference of Boeing Alert Service 
Bulletin 747-53A2349, Revision 1, dated October 12, 2000, as listed 
in the regulations, is approved by the Director of the Federal 
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) The incorporation by reference of Boeing Service Bulletin 
747-53-2349, dated June 27, 1991, was approved previously by the 
Director of the Federal Register as of June 11, 1993 (58 FR 27927, 
May 12, 1993).

[[Page 36085]]

    (3) 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

    (k) This amendment becomes effective on June 27, 2002.

    Issued in Renton, Washington, on May 14, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-12635 Filed 5-22-02; 8:45 am]
BILLING CODE 4910-13-P