[Federal Register Volume 75, Number 119 (Tuesday, June 22, 2010)]
[Proposed Rules]
[Pages 35356-35360]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-15054]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2010-0552; Directorate Identifier 2009-NM-095-AD]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Model 747-100, 747-
200B, and 747-200F 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 supersede two existing airworthiness
directives (AD) that apply to certain Model 747-100, 747-200B, and 747-
200F series airplanes. The existing ADs currently require inspections
to detect fatigue-related skin cracks and corrosion of the skin panel
lap joints in the fuselage upper lobe, and repair if necessary. One of
the existing ADs, AD 94-12-09, also requires modification of certain
lap joints and inspection of modified lap joints. The other AD, AD 90-
15-06, requires repetitive detailed external visual inspections of the
fuselage skin at the upper lobe skin lap joints for cracks and evidence
of corrosion, and related investigative and corrective actions. This
proposed AD would reduce the maximum interval of the post-modification
inspections, and adds post-repair inspection requirements for certain
airplanes. This proposed AD results from reports of cracking on
modified airplanes. We are proposing this AD to detect and correct
fatigue cracking and corrosion in the fuselage upper lobe skin lap
joints, which could lead to rapid decompression of the airplane and
inability of the structure to carry fail-safe loads.
DATES: We must receive comments on this proposed AD by August 6, 2010.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations,
[[Page 35357]]
M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue,
SE., Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, 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 Airplanes, Attention: Data & Services Management,
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; e-mail [email protected];
Internet https://www.myboeingfleet.com. You may review copies of the
referenced service information at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue SW., Renton, Washington. For information
on the availability of this material at the FAA, call 425-227-1221 or
425-227-1152.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Office (telephone 800-647-5527) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.
FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437;
fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2010-0552;
Directorate Identifier 2009-NM-095-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD because of those comments.
We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.
Discussion
On July 3, 1990, we issued AD 90-15-06, Amendment 39-6653 (55 FR
28600, July 12, 1990), for certain Boeing Model 747-100, 747-200B, and
747-200F series airplanes. That AD requires repetitive detailed
external visual inspections of the fuselage skin at the upper lobe skin
lap joints for cracks and evidence of corrosion, and related
investigative and corrective actions. We issued that AD to detect and
correct fatigue cracking and corrosion in the fuselage skins, which
could lead to rapid decompression of the airplane and inability of the
structure to carry fail-safe loads.
On June 2, 1994, we issued AD 94-12-09, Amendment 39-8937 (59 FR
30285, June 13, 1994), for certain Boeing Model 747-100, 747-200B, and
747-200F series airplanes. That AD requires inspections to detect
fatigue cracking and corrosion of the skin panel lap joints in the
fuselage upper lobe, and repair if necessary. That AD also requires
modification of certain lap joints and inspections of modified lap
joints. That AD resulted from reports of cracking, corrosion, and
bulging of the skin lap joints on Boeing Model 747-100, 747-200B, and
747-200F series airplanes. We issued that AD to prevent rapid
decompression of the airplane and the inability of the structure to
carry fail-safe loads.
Actions Since Existing AD Was Issued
Since we issued AD 94-12-09 and AD 90-15-06, Boeing has performed a
fleet-wide evaluation of the skin panel lap joints for widespread
fatigue damage (WFD) and determined that the post-modification
inspection interval of AD 94-12-09 needs to be reduced. In addition,
lap joints where the upper (overlapping) skin thickness at the upper
row of fasteners is 0.071 inch or less need to be further modified to
preclude WFD. WFD of the lap joints can link up and result in large
skin cracks, and possible rapid in-flight decompression of the
airplane.
Related Rulemaking
We are considering issuing related rulemaking to address the
identified unsafe condition. The related rulemaking would refer to
Revision 1, dated April 16, 2009, of Boeing Service Bulletin 747-
53A2463, which is related to this unsafe condition. That AD would
require further modification of all the affected lap joints with an
upper skin thickness of 0.071 inch or less. Once the modification in
accordance with Boeing Service Bulletin 747-53A2463 is accomplished,
the post-modification inspections will be accomplished in accordance
with that rule, not this one.
Relevant Service Information
AD 90-15-06 refers to Boeing Service Bulletin 747-53-2307, dated
December 21, 1989, as the appropriate source of service information for
the required actions specified in that AD. AD 94-12-09 refers to Boeing
Service Bulletin 747-53-2307, Revision 2, dated October 14, 1993, as
the appropriate source of service information for the required actions
specified in that AD. We have reviewed Boeing Service Bulletin 747-53-
2307, Revision 3, dated April 16, 2009. Boeing Service Bulletin 747-53-
2307, Revision 3, dated April 16, 2009, reduces the maximum post-
modification inspection interval specified in Boeing Service Bulletin
747-53-2307, Revision 2, dated October 14, 1993, from 3,000 to 1,000
flight cycles and references a structural modification for lap joints
where the upper (overlapping) skin thickness at the upper row of
fasteners is 0.071 inch or less. In addition, Boeing Service Bulletin
747-53-2307, Revision 3, dated April 16, 2009, specifies a post-repair
internal surface high frequency eddy current (HFEC) inspection of the
skin at any external doubler repairs greater than 40 inches in length
(in the horizontal direction).
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to develop on other airplanes of the
same type design. For this reason, we are proposing this AD, which
would supersede AD 90-15-06 and AD 94-12-09. This proposed AD does not
retain any requirements of AD 90-15-06. This proposed AD would retain
the inspection requirements of AD 94-12-09 but with reduced maximum
intervals of the post-modification inspections from 3,000 flight cycles
to 1,000 flight cycles. In addition, this proposed AD would require a
post-repair internal surface HFEC inspection of the skin at any
external doubler repairs greater than 40 inches in length (in the
horizontal direction). This proposed AD would also require
accomplishing the actions specified in Boeing Service Bulletin 747-53-
2307, Revision 3, dated April 16, 2009, described previously, except as
discussed under ``Differences Between the Proposed AD and Service
Bulletin.''
[[Page 35358]]
Differences Between the Proposed AD and Service Bulletin
Boeing Service Bulletin 747-53-2307, Revision 3, dated April 16,
2009, specifies to contact the manufacturer for instructions on how to
repair certain conditions, but this proposed AD would require repairing
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 the Boeing Commercial
Airplanes Organization Designation Authorization that we have
authorized to make those findings.
Change to Existing AD
This proposed AD would retain the requirements of AD 94-12-09, and
none of the requirements of AD 90-15-06. Since AD 94-12-09 was issued,
the AD format has been revised, and certain paragraphs have been
rearranged. As a result, the corresponding paragraph identifiers have
changed in this proposed AD, as listed in the following table:
Revised Paragraph Identifiers
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Corresponding requirement in
Requirement in AD 94-12-09 this proposed AD
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paragraph (a).......................... paragraph (g).
paragraph (b).......................... paragraph (h).
paragraph (c).......................... paragraph (i).
paragraph (d).......................... paragraph (j).
paragraph (e).......................... paragraph (k).
paragraph (f).......................... paragraph (l).
paragraph (g).......................... paragraph (m).
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Costs of Compliance
There are about 23 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
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Number of
Average U.S.-
Action Work hours labor rate Parts Cost per airplane registered Fleet cost
per hour airplanes
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Inspection (required by AD 94-12-09)..... 208 $85 $0 $17,680 per inspection cycle 7 $123,760 per inspection
cycle.
Modification (required by AD 94-12-09)... 8,160 85 0 $693,600.................... 7 $4,855,200.
Post-Modification Inspection (required by 56 85 0 $4,760 per inspection cycle. 7 $33,320 per inspection
AD 94-12-09). cycle.
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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, Incorporation by
reference, 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 removing Amendment 39-6653 (55 FR
28600, July 12, 1990), and Amendment 39-8937 (59 FR 30285, June 13,
1994), and adding the following new AD:
The Boeing Company: Docket No. FAA-2010-0552; Directorate Identifier
2009-NM-095-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by August 6,
2010.
Affected ADs
(b) This AD supersedes AD 90-15-06, Amendment 39-6653; and AD
94-12-09, Amendment 39-8937.
Applicability
(c) This AD applies to The Boeing Company Model 747-100, 747-
200B, and 747-200F series airplanes, certificated in any category,
as identified in Boeing Service Bulletin 747-53-2307, Revision 3,
dated April 16, 2009.
[[Page 35359]]
Subject
(d) Air Transport Association (ATA) of America Code 53:
Fuselage.
Unsafe Condition
(e) This AD results from reports of fatigue cracking. The
Federal Aviation Administration is issuing this AD to detect and
correct fatigue cracking and corrosion in the fuselage upper lobe
skin panel lap joints, which could lead to the rapid decompression
of the airplane and the inability to carry fail-safe loads.
Compliance
(f) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Restatement of Requirements of AD 94-12-09, With Revised Service
Information
Inspection
(g) Within 1,000 flight cycles after July 13, 1994 (the
effective date of AD 94-12-09), and thereafter at the intervals
specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD,
perform inspections at the upper lobe skin panel lap joints in
accordance with Boeing Service Bulletin 747-53-2307, Revision 2,
dated October 14, 1993; or Revision 3, dated April 16, 2009. After
the effective date of this AD, only Revision 3 may be used.
(1) Perform a detailed external visual inspection to detect
cracks and evidence of corrosion (bulging skin between fasteners,
blistered paint, dished fasteners, popped rivet heads, or loose
fasteners) in accordance with Boeing Service Bulletin 747-53-2307,
Revision 2, dated October 14, 1993; or Revision 3, dated April 16,
2009. After the effective date of this AD, only Revision 3 may be
used. Repeat that inspection thereafter at intervals not to exceed
2,000 flight cycles until the modification required by paragraph (k)
of this AD is accomplished.
(2) Perform a high frequency eddy current (HFEC) inspection to
detect cracks in the skin at the upper row of fasteners of the skin
panel lap joints forward of body station (BS) 1000 in accordance
with Boeing Service Bulletin 747-53-2307, Revision 2, dated October
14, 1993; or Revision 3, dated April 16, 2009. After the effective
date of this AD, only Revision 3 may be used. Repeat that inspection
thereafter at intervals not to exceed 4,000 flight cycles until the
modification required by paragraph (k) of this AD is accomplished.
(3) Perform a HFEC inspection to detect cracks in the skin at
the upper row of fastener holes of the skin panel lap joints aft of
BS 1480 to 2360 in accordance with Boeing Service Bulletin 747-53-
2307, Revision 2, dated October 14, 1993; or Revision 3, dated April
16, 2009. After the effective date of this AD, only Revision 3 may
be used. Repeat that inspection thereafter at intervals not to
exceed 6,000 flight cycles until the modification required by
paragraph (k) of this AD is accomplished.
(h) If any crack is found during any inspection required by
paragraph (g) or (l) of this AD, or if any corrosion is found for
which material loss exceeds 10 percent of the material thickness,
accomplish paragraphs (h)(1) and (h)(2) of this AD in accordance
with Boeing Service Bulletin 747-53-2307, Revision 2, dated October
14, 1993; or Revision 3, dated April 16, 2009. After the effective
date of this AD, use only Revision 3.
(1) Prior to further flight, repair any crack or corrosion
found, in accordance with Boeing Service Bulletin 747-53-2307,
Revision 2, dated October 14, 1993; or Revision 3, dated April 16,
2009. After the effective date of this AD, only Revision 3 may be
used.
(2) Within 18 months after accomplishing the repair, accomplish
the ``full'' modification described in Boeing Service Bulletin 747-
53-2307, Revision 2, dated October 14, 1993; or Revision 3, dated
April 16, 2009; for the remainder of any skin panel lap joint in
which a crack is found, or in which corrosion is found that exceeds
10 percent of the material thickness, in accordance with Boeing
Service Bulletin 747-53-2307, Revision 2, dated October 14, 1993; or
Revision 3, dated April 16, 2009. After the effective date of this
AD, only Revision 3 may be used.
(i) If no crack is found during any inspection required by
paragraph (g) of this AD, but corrosion is found for which the
material loss does not exceed 10 percent of the material thickness:
Accomplish the actions specified in paragraphs (i)(1) and (i)(2) of
this AD for the entire affected skin panel lap joint, in accordance
with Boeing Service Bulletin 747-53-2307, Revision 2, dated October
14, 1993; or Revision 3, dated April 16, 2009. After the effective
date of this AD, only Revision 3 may be used.
(1) Within 500 flight cycles after accomplishing the inspection
during which the corrosion was found, and thereafter at intervals
not to exceed 500 flight cycles until the ``full'' modification
required by paragraph (i)(2) of this AD is accomplished: Perform a
HFEC inspection to detect cracks of the corroded skin panel lap
joint, in accordance with Boeing Service Bulletin 747-53-2307,
Revision 2, dated October 14, 1993; or Revision 3, dated April 16,
2009. After the effective date of this AD, only Revision 3 may be
used.
(2) Within 36 months after accomplishing the inspection during
which the corrosion was found: Accomplish the ``full'' modification,
in accordance with Boeing Service Bulletin 747-53-2307, Revision 2,
dated October 14, 1993; or Revision 3, dated April 16, 2009. After
the effective date of this AD, only Revision 3 may be used.
(j) The inspections required by paragraph (g) of this AD shall
be performed by removing the paint and using an approved chemical
stripper; or by ensuring that each fastener head is clearly visible.
(k) Except as provided in paragraph (m) of this AD, prior to the
accumulation of 20,000 total flight cycles, or within the next 1,000
flight cycles after July 13, 1994, whichever occurs later:
Accomplish the modification described in Boeing Service Bulletin
747-53-2307, Revision 2, dated October 14, 1993; or Revision 3,
dated April 16, 2009; as a ``full'' modification of the skin panel
lap joints at the locations specified in paragraphs (k)(1) and
(k)(2) of this AD, as applicable, in accordance with Boeing Service
Bulletin 747-53-2307, Revision 2, dated October 14, 1993; or
Revision 3, dated April 16, 2009. After the effective date of this
AD, use only Revision 3. Accomplishment of this modification
terminates the repetitive inspection requirements of paragraph (g)
of this AD.
(1) For airplane line numbers 001 through 058, inclusive: Modify
the skin panel lap joints at Stringer 12 (left and right), station
520 to 1,000; and Stringer 19 (left and right), station 520 to 740.
(2) For airplane line numbers 59 through 200, inclusive: Modify
the skin panel lap joints at Stringer 12 (left and right), station
740 to 1,000; and Stringer 19 (left and right), station 520 to 740.
(l) For all airplanes: Perform an external HFEC inspection to
detect skin cracks of any modified skin panel lap joints at the
times specified in paragraphs (1)(1), (1)(2), and (1)(3) of this AD,
as applicable, in accordance with Boeing Service Bulletin 747-53-
2307, Revision 2, dated October 14, 1993; or Revision 3, dated April
16, 2009. As of the effective date of this AD, only Revision 3 may
be used. Repeat that inspection thereafter at intervals not to
exceed 3,000 flight cycles, except as required by paragraph (n) of
this AD.
(1) For skin panel lap joints on which the ``full'' modification
has been accomplished: Within 10,000 flight cycles after
accomplishment of that modification.
(2) For skin panel lap joints on which the ``optional''
(partial) modification has been accomplished: Within 7,000 flight
cycles after accomplishment of that modification.
(3) For skin panel lap joints having deep countersink fasteners
located at Section 42 on which the ``full'' modification, as
described in Boeing Service Bulletin 747-53-2307, dated December 21,
1989, has been accomplished: Within 5,000 flight cycles after
accomplishment of that modification.
(m) In lieu of the ``full'' modification required by paragraph
(k) of this AD, the ``optional'' (partial) modification described in
Boeing Service Bulletin 747-53-2307, Revision 2, dated October 14,
1993; or Revision 3, dated April 16, 2009; may be accomplished for
skin panels that have an outer thickness of 0.090 inches or less,
and that do not have any cracks, corrosion, or an existing
structural repair on the skin panel lap joint. After the effective
date of this AD, only Revision 3 may be used. The ``optional''
(partial) modification shall not be accomplished at deep countersink
fastener locations. Accomplishment of this modification terminates
the repetitive inspection requirements of paragraph (g) of this AD.
New Requirements of This AD
Post-Modification Inspection at Reduced Intervals
(n) Repeat the inspection required by paragraph (l) of this AD
at the earlier of the times specified in paragraphs (n)(1) and
(n)(2) of this AD. Thereafter, repeat the inspection at intervals
not to exceed 1,000 flight cycles.
(1) Within 3,000 flight cycles after the last inspection done in
accordance with paragraph (l) of this AD.
[[Page 35360]]
(2) Within 1,000 flight cycles after the last inspection done in
accordance with paragraph (l) of this AD or 500 flight cycles after
the effective date of this AD, whichever occurs later.
Post-Repair Inspection for External Doubler Repair
(o) For all airplanes: Do an internal surface HFEC inspection
for cracking of the skin at any external doubler repairs greater
than 40 inches in length (in the horizontal direction) within 1,000
flight cycles after the effective date of this AD, in accordance
with the Accomplishment Instructions of Boeing Service Bulletin 747-
53-2307, Revision 3, dated April 16, 2009. Thereafter, perform that
inspection at intervals not to exceed 3,000 flight cycles.
(p) If any cracking is found during any inspection required by
paragraph (o) of this AD, repair in accordance with the
Accomplishment Instructions of Boeing Service Bulletin 747-53-2307,
Revision 3, dated April 16, 2009.
Alternative Methods of Compliance (AMOCs)
(q)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. Send information to
ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA,
Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton,
Washington 98057-3356; telephone (425) 917-6437; fax (425) 917-6590.
Or, e-mail information to [email protected].
(2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your principal maintenance inspector (PMI) or
principal avionics inspector (PAI), as appropriate, or lacking a
principal inspector, your local Flight Standards District Office.
The AMOC approval letter must specifically reference this AD.
(3) 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
Organization Designation Authorization 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.
(4) AMOCs approved previously in accordance with AD 90-15-06,
Amendment 39-6653; and AD 94-12-09, Amendment 39-8937; are approved
as AMOCs for the corresponding provisions of this AD.
Issued in Renton, Washington, on June 16, 2010.
Robert D. Breneman,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-15054 Filed 6-21-10; 8:45 am]
BILLING CODE 4910-13-P