Airworthiness Directives; Boeing Model 777-200 Series Airplanes, 25599-25601 [E8-10059]
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Federal Register / Vol. 73, No. 89 / Wednesday, May 7, 2008 / Proposed Rules
low-pressure (LP) turbine rear frames, part
numbers 338–171–703–0; 338–171–704–0;
338–171–705–0; and 338–171–706–0,
installed. These engines are installed on, but
not limited to, Airbus A318, A319, A320, and
A321 series airplanes.
Unsafe Condition
(d) This AD results from a refined lifing
analysis by the engine manufacturer that
shows the need to identify initial and
repetitive inspection thresholds for
inspecting certain LP turbine rear frames. We
are issuing this AD to detect low-cyclefatigue cracks in the LP turbine rear frame,
which could result in engine separation from
the airplane, possibly leading to loss of
control 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.
Initial Inspection
(f) Perform an initial eddy current
inspection (ECI) of the LP turbine rear frame
using paragraphs 3.A. through 3.A.(7)(d) of
the Accomplishment Instructions of CFM
International, S.A. Service Bulletin (SB) No.
CFM56–5B S/B 72–0620, Revision 1, dated
December 20, 2007, at the following
compliance times:
(1) For commercial engine applications,
within 25,000 cycles-since-new (CSN) on the
LP turbine rear frame.
(2) For corporate engine applications,
within 19,000 CSN on the LP turbine rear
frame.
(3) For engines with unknown LP turbine
rear frame CSN, within 300 cycles from the
effective date of this AD.
Repetitive Inspections
(g) Perform repetitive ECIs of the LP
turbine rear frame using paragraphs 3.A.
through 3.A.(7)(d) of the Accomplishment
Instructions of CFM International, S.A. SB
No. CFM56–5B S/B 72–0620, Revision 1,
dated December 20, 2007. Use the inspection
intervals in paragraph 3.A.(8) of the
Accomplishment Instructions of CFM
International, S.A. SB No. CFM56–5B S/B
72–0620, Revision 1, dated December 20,
2007.
rwilkins on PROD1PC63 with PROPOSALS
LP Turbine Rear Frame Removal Criteria
(h) Remove LP turbine rear frames from
service that have a single crack length of 2.56
inches (65 mm) or longer, or multiple cracks
with accumulated crack length of 2.56 inches
(65 mm) or longer.
Alternative Methods of Compliance
(i) The Manager, Engine Certification
Office, has the authority to approve
alternative methods of compliance for this
AD if requested using the procedures found
in 14 CFR 39.19.
Related Information
(j) European Aviation Safety Agency AD
2007–0221, dated August 13, 2007, also
addresses the subject of this AD.
(k) Contact Stephen Sheely, Aerospace
Engineer, Engine Certification Office, FAA,
VerDate Aug<31>2005
18:18 May 06, 2008
Jkt 214001
Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA
01803; e-mail: stephen.k.sheely@faa.gov;
telephone (781) 238–7750; fax (781) 238–
7199, for more information about this AD.
Issued in Burlington, Massachusetts, on
April 29, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller
Directorate, Aircraft Certification Service.
[FR Doc. E8–10050 Filed 5–6–08; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2008–0520; Directorate
Identifier 2008–NM–018–AD]
RIN 2120–AA64
Airworthiness Directives; Boeing
Model 777–200 Series Airplanes
Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking
(NPRM).
AGENCY:
SUMMARY: We propose to adopt a new
airworthiness directive (AD) for certain
Boeing Model 777–200 series airplanes.
This proposed AD would require
repetitive inspections for any wrinkle in
certain external skin panels, and for
cracking at the fuselage bulkhead shear
tie end fastener locations at certain
stations of section 48 of the fuselage;
and doing related investigative and
corrective actions if necessary. This
proposed AD results from a report of
cracks found in the external skin on the
left and right sides of the Section 48
panel of the fuselage on two airplanes
with skin wrinkles found at two of the
external crack locations. We are
proposing this AD to detect and correct
wrinkles and cracks in certain external
skin panels of Section 48, which could
join together and result in reduced
structural integrity of support structure
for the vertical and horizontal stabilizers
and inability of the airplane to sustain
limit loads.
DATES: We must receive comments on
this proposed AD by June 23, 2008.
ADDRESSES: You may send comments by
any of the following methods:
• Federal eRulemaking Portal: Go to
https://www.regulations.gov. Follow the
instructions for submitting comments.
• Fax: 202–493–2251.
• Mail: U.S. Department of
Transportation, Docket Operations, M–
30, West Building Ground Floor, Room
W12–140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590.
PO 00000
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25599
• 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 AD, contact Boeing Commercial
Airplanes, P.O. Box 3707, Seattle,
Washington 98124–2207.
Examining the AD Docket
You may examine the AD docket on
the Internet at https://
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:
Duong Tran, Aerospace Engineer,
Airframe Branch, ANM–120S, FAA,
Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton,
Washington 98057–3356; telephone
(425) 917–6452; 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–2008–0520; Directorate Identifier
2008–NM–018–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 https://
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
We have received a report of cracks
found in the external skin on the left
and right sides of the section 48 panel
of the fuselage on two airplanes. There
were ten external skin cracks on one
airplane with 22,732 total flight hours
and 20,286 total flight cycles; the cracks
were 0.20 to 0.50 inch in length at
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Federal Register / Vol. 73, No. 89 / Wednesday, May 7, 2008 / Proposed Rules
Stations 2195.75 and 2221.65, between
Stringers 6 to 10 on the left and right
sides. In addition, skin wrinkles 4.5 and
5.0 inches long and 1.0 inch wide and
0.014 inch deep were found at two of
the external skin crack locations. A
second report indicated that three
external skin cracks, 0.12 to 0.20 inches
in length were found at Station 2195.75,
above Stringer 7 on the left side, on an
airplane with 22,147 total flight hours
and 19,281 total flight cycles. This
condition, if not corrected, could result
in reduced structural integrity of
support structure for the vertical and
horizontal stabilizers and inability of
the airplane to sustain limit loads.
rwilkins on PROD1PC63 with PROPOSALS
Relevant Service Information
We have reviewed Boeing Alert
Service Bulletin 777–53A0051, dated
November 8, 2007. The alert service
bulletin describes procedures for
repetitive general visual inspections for
any wrinkle of the external skin at
Stations 2195.75, 2221.65, and 2245.70
of the Section 48 panel of the fuselage,
between stringers 5 and 10 on the left
and right sides. The service bulletin also
describes procedures for repetitive high
frequency eddy current (HFEC) and
detailed inspections for cracking at the
fuselage bulkhead shear tie end fastener
locations of the external skin at Stations
2195.75, 2221.65, and 2245.70 of the
section 48 panel of the fuselage;
between stringers 5 and 10 on the left
and right sides. In addition, the service
bulletin describes performing related
investigative and corrective actions if
necessary. The corrective actions
include removing any skin wrinkle,
repairing any skin crack, and installing
a skin repair if any wrinkle or crack is
found. The related investigative actions
include an internal HFEC inspection of
the repair doubler edge row fasteners for
cracking if a skin repair is installed. The
service bulletin also recommends
contacting Boeing for repair data if any
crack is found that is 1.0 or more inches
in length.
The compliance times for the
inspections specified in the service
bulletin are as follows:
• General visual and external HFEC
inspections for any wrinkle and
cracking of the skin panels and
bulkhead shear tie end fastener
locations at Stations 2195.75, 2221.65,
and 2245.70 of the Section 48 panel of
the fuselage, between stringers 5 and 10:
Before 16,000 total flight cycles or
within 2,300 flight cycles after the date
on the service bulletin, whichever
occurs later. If no wrinkle or skin crack
is found, the service bulletin specifies
repeating the inspections thereafter at
VerDate Aug<31>2005
18:18 May 06, 2008
Jkt 214001
intervals not to exceed 4,500 flight
cycles.
• Internal HFEC inspection of the
repair doubler shear tie end fasteners
and external and internal detailed
inspection of the tripler, doubler, skin,
shear tie, stringer, or fuselage bulkhead
(fastener locations): Within 30,000 flight
cycles after installation of the repair.
• Internal HFEC inspection of the
repair doubler edge row fasteners and
external and internal detailed
inspection of the tripler, doubler, skin,
shear tie, stringer or fuselage bulkhead
within the repair area: Before 30,000
total flight cycles, or within 16,000
flight cycles after installation of the
repair, whichever occurs first. If no
cracking is found, the service bulletin
describes repeating the inspections
thereafter at intervals not to exceed
16,000 flight cycles. If any crack is
found, the service bulletin recommends
contacting Boeing for repair data and
repairing.
FAA’s Determination and Requirements
of This Proposed AD
We are proposing this AD because we
evaluated all relevant information and
determined the unsafe condition
described previously is likely to exist or
develop in other products of the same
type design. This proposed AD would
require accomplishing the actions
specified in the service information
described previously, except as
discussed under ‘‘Difference Between
the Proposed AD and Service
Information.’’
Difference Between the Proposed AD
and Service Information
The alert service bulletin 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 an
Authorized Representative for the
Boeing Commercial Airplanes
Delegation Option Authorization
Organization whom we have authorized
to make those findings.
Costs of Compliance
We estimate that the inspections in
this proposed AD would affect 13
airplanes of U.S. registry. We also
estimate that it would take about 15
work-hours per product to comply with
this proposed AD. The average labor
rate is $80 per work-hour. Based on
these figures, we estimate the cost of
this proposed AD to the U.S. operators
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to be $15,600, or $1,200 per product, 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 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 this 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.
You can find our regulatory
evaluation and the estimated costs of
compliance in the AD Docket.
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:
E:\FR\FM\07MYP1.SGM
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Federal Register / Vol. 73, No. 89 / Wednesday, May 7, 2008 / Proposed Rules
Authority: 49 U.S.C. 106(g), 40113, 44701.
§ 39.13
[Amended]
2. The FAA amends § 39.13 by adding
the following new AD:
Boeing: Docket No. FAA–2008–0520;
Directorate Identifier 2008–NM–018–AD.
Comments Due Date
(a) We must receive comments by June 23,
2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 777–
200 series airplanes, certificated in any
category; as identified in Boeing Alert
Service Bulletin 777–53A0051, dated
November 8, 2007.
Unsafe Condition
(d) This AD results from a report of cracks
found in the external skin on the left and
right sides of the section 48 fuselage panel on
two airplanes with skin wrinkles found at
two of the external crack locations. We are
issuing this AD to detect and correct wrinkles
and cracks in certain external skin panels of
section 48, which could join together and
result in reduced structural integrity of
support structure for the vertical and
horizontal stabilizers and inability of the
airplane to sustain limit loads.
Compliance
(e) Comply with this AD within the
compliance times specified, unless already
done.
rwilkins on PROD1PC63 with PROPOSALS
Repetitive Inspections/Investigative and
Corrective Actions
(f) At the applicable compliance times
specified in paragraph 1.E., ‘‘Compliance’’ of
Boeing Alert Service Bulletin 777–53A0051,
dated November 8, 2007, except as provided
by paragraph (g) of this AD: Do the applicable
inspections for any wrinkle of the external
skin and for cracking at the fuselage
bulkhead shear tie end fastener locations at
Stations 2195.75, 2221.65, and 2245.70 of the
section 48 panel of the fuselage, between
stringers 5 and 10 on the left and right sides;
and do all the applicable investigative and
corrective actions; by doing all of the
applicable actions in accordance with the
Accomplishment Instructions of the service
bulletin, except as provided by paragraph (h)
of this AD. Do all applicable investigative
and corrective actions before further flight.
Repeat the applicable inspections thereafter
at the applicable intervals specified in
paragraph 1.E. of the service bulletin.
found during any inspection required by this
AD, and the service bulletin specifies to
contact Boeing for appropriate action: Before
further flight, repair the crack using a method
approved in accordance with the procedures
specified in paragraph (i) of this AD.
Alternative Methods of Compliance
(AMOCs)
(i)(1) The Manager, Seattle Aircraft
Certification Office (ACO), FAA, ATTN:
Duong Tran, Aerospace Engineer, Airframe
Branch, ANM–120S, FAA, Seattle ACO, 1601
Lind Avenue, SW., Renton, Washington
98057–3356; telephone (425) 917–6452; fax
(425) 917–6590 has the authority to approve
AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19.
(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 appropriate principal inspector
(PI) in the FAA Flight Standards District
Office (FSDO), or lacking a PI, your local
FSDO.
(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 Delegation Option
Authorization Organization who has been
authorized by the Manager, Seattle ACO, to
make those findings. For a repair method to
be approved, the repair must meet the
certification basis of the airplane.
Issued in Renton, Washington, on April 25,
2008.
Ali Bahrami,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. E8–10059 Filed 5–6–08; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2007–0043; Directorate
Identifier 2007–NM–058–AD]
RIN 2120–AA64
Airworthiness Directives; Boeing
Model 747–100, 747–100B, 747–100B
SUD, 747–200B, 747–200C, 747–200F,
747–300, 747–400, 747SR, and 747SP
Series Airplanes
Exception to Compliance Times
(g) Where Boeing Alert Service Bulletin
777–53A0051, dated November 8, 2007,
specifies counting the compliance time from
‘‘* * * the date on this service bulletin,’’ this
AD requires counting the compliance time
from the effective date of this AD.
AGENCY:
Exception to Corrective Actions
(h) If any damage beyond the repair limits
specified in Boeing Alert Service Bulletin
777–53A0051, dated November 8, 2007, is
SUMMARY: The FAA is revising an earlier
NPRM for an airworthiness directive
(AD) that applies to certain Boeing
Model 747 series airplanes. The original
VerDate Aug<31>2005
18:18 May 06, 2008
Jkt 214001
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Supplemental notice of
proposed rulemaking (NPRM);
reopening of comment period.
PO 00000
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25601
NPRM would have superseded an
existing AD that currently requires
inspecting to detect cracking in certain
lower lobe fuselage skin lap joints,
doing repetitive inspections for cracking
at certain fastener locations having
countersunk fasteners, and replacing
countersunk fasteners with protruding
head fasteners at certain fastener
locations. The original NPRM proposed
to replace a previous high-frequency
eddy current (HFEC) inspection method
with a new HFEC inspection method,
add a one-time inspection for cracking
of certain airplanes, and terminate the
adjustment factor for the inspection
compliance times based on cabin
differential pressure. The original
NPRM also included an inspection at an
additional lap joint. The original NPRM
resulted from reports of fuselage skin
cracks found at certain countersunk
fastener locations in the upper row of
lap joints near the wing-to-body fairings,
and from a report that the presence of
Alodine-coated rivets could cause faulty
results during the required inspections
using the optional sliding probe HFEC
inspection method specified in the
existing AD. This new action revises the
original NPRM by including inspections
at additional lap joint locations and by
removing inspections at certain other
lap joint locations. We are proposing
this supplemental NPRM to prevent
reduced structural integrity of the
fuselage.
DATES: We must receive comments on
this supplemental NPRM by June 2,
2008.
ADDRESSES: You may send comments by
any of the following methods:
• Federal eRulemaking Portal: Go to
https://www.regulations.gov. Follow the
instructions for submitting comments.
• Fax: (202) 493–2251.
• Mail: U.S. Department of
Transportation, Docket Operations, 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 AD, contact Boeing Commercial
Airplanes, P.O. Box 3707, Seattle,
Washington 98124–2207.
Examining the AD Docket
You may examine the AD docket on
the Internet at https://
www.regulations.gov; or in person at the
Docket Management Facility between 9
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]]>Agencies
[Federal Register Volume 73, Number 89 (Wednesday, May 7, 2008)]
[Proposed Rules]
[Pages 25599-25601]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-10059]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-0520; Directorate Identifier 2008-NM-018-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 777-200 Series Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain Boeing Model 777-200 series airplanes. This proposed AD would
require repetitive inspections for any wrinkle in certain external skin
panels, and for cracking at the fuselage bulkhead shear tie end
fastener locations at certain stations of section 48 of the fuselage;
and doing related investigative and corrective actions if necessary.
This proposed AD results from a report of cracks found in the external
skin on the left and right sides of the Section 48 panel of the
fuselage on two airplanes with skin wrinkles found at two of the
external crack locations. We are proposing this AD to detect and
correct wrinkles and cracks in certain external skin panels of Section
48, which could join together and result in reduced structural
integrity of support structure for the vertical and horizontal
stabilizers and inability of the airplane to sustain limit loads.
DATES: We must receive comments on this proposed AD by June 23, 2008.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to https://
www.regulations.gov. Follow the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, 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 AD, contact Boeing
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.
Examining the AD Docket
You may examine the AD docket on the Internet at https://
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: Duong Tran, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425)
917-6452; 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-2008-0520;
Directorate Identifier 2008-NM-018-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 https://
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
We have received a report of cracks found in the external skin on
the left and right sides of the section 48 panel of the fuselage on two
airplanes. There were ten external skin cracks on one airplane with
22,732 total flight hours and 20,286 total flight cycles; the cracks
were 0.20 to 0.50 inch in length at
[[Page 25600]]
Stations 2195.75 and 2221.65, between Stringers 6 to 10 on the left and
right sides. In addition, skin wrinkles 4.5 and 5.0 inches long and 1.0
inch wide and 0.014 inch deep were found at two of the external skin
crack locations. A second report indicated that three external skin
cracks, 0.12 to 0.20 inches in length were found at Station 2195.75,
above Stringer 7 on the left side, on an airplane with 22,147 total
flight hours and 19,281 total flight cycles. This condition, if not
corrected, could result in reduced structural integrity of support
structure for the vertical and horizontal stabilizers and inability of
the airplane to sustain limit loads.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 777-53A0051, dated
November 8, 2007. The alert service bulletin describes procedures for
repetitive general visual inspections for any wrinkle of the external
skin at Stations 2195.75, 2221.65, and 2245.70 of the Section 48 panel
of the fuselage, between stringers 5 and 10 on the left and right
sides. The service bulletin also describes procedures for repetitive
high frequency eddy current (HFEC) and detailed inspections for
cracking at the fuselage bulkhead shear tie end fastener locations of
the external skin at Stations 2195.75, 2221.65, and 2245.70 of the
section 48 panel of the fuselage; between stringers 5 and 10 on the
left and right sides. In addition, the service bulletin describes
performing related investigative and corrective actions if necessary.
The corrective actions include removing any skin wrinkle, repairing any
skin crack, and installing a skin repair if any wrinkle or crack is
found. The related investigative actions include an internal HFEC
inspection of the repair doubler edge row fasteners for cracking if a
skin repair is installed. The service bulletin also recommends
contacting Boeing for repair data if any crack is found that is 1.0 or
more inches in length.
The compliance times for the inspections specified in the service
bulletin are as follows:
General visual and external HFEC inspections for any
wrinkle and cracking of the skin panels and bulkhead shear tie end
fastener locations at Stations 2195.75, 2221.65, and 2245.70 of the
Section 48 panel of the fuselage, between stringers 5 and 10: Before
16,000 total flight cycles or within 2,300 flight cycles after the date
on the service bulletin, whichever occurs later. If no wrinkle or skin
crack is found, the service bulletin specifies repeating the
inspections thereafter at intervals not to exceed 4,500 flight cycles.
Internal HFEC inspection of the repair doubler shear tie
end fasteners and external and internal detailed inspection of the
tripler, doubler, skin, shear tie, stringer, or fuselage bulkhead
(fastener locations): Within 30,000 flight cycles after installation of
the repair.
Internal HFEC inspection of the repair doubler edge row
fasteners and external and internal detailed inspection of the tripler,
doubler, skin, shear tie, stringer or fuselage bulkhead within the
repair area: Before 30,000 total flight cycles, or within 16,000 flight
cycles after installation of the repair, whichever occurs first. If no
cracking is found, the service bulletin describes repeating the
inspections thereafter at intervals not to exceed 16,000 flight cycles.
If any crack is found, the service bulletin recommends contacting
Boeing for repair data and repairing.
FAA's Determination and Requirements of This Proposed AD
We are proposing this AD because we evaluated all relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the same type design.
This proposed AD would require accomplishing the actions specified in
the service information described previously, except as discussed under
``Difference Between the Proposed AD and Service Information.''
Difference Between the Proposed AD and Service Information
The alert service bulletin 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 an Authorized Representative
for the Boeing Commercial Airplanes Delegation Option Authorization
Organization whom we have authorized to make those findings.
Costs of Compliance
We estimate that the inspections in this proposed AD would affect
13 airplanes of U.S. registry. We also estimate that it would take
about 15 work-hours per product to comply with this proposed AD. The
average labor rate is $80 per work-hour. Based on these figures, we
estimate the cost of this proposed AD to the U.S. operators to be
$15,600, or $1,200 per product, 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 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 this 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.
You can find our regulatory evaluation and the estimated costs of
compliance in the AD Docket.
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:
[[Page 25601]]
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 AD:
Boeing: Docket No. FAA-2008-0520; Directorate Identifier 2008-NM-
018-AD.
Comments Due Date
(a) We must receive comments by June 23, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 777-200 series airplanes,
certificated in any category; as identified in Boeing Alert Service
Bulletin 777-53A0051, dated November 8, 2007.
Unsafe Condition
(d) This AD results from a report of cracks found in the
external skin on the left and right sides of the section 48 fuselage
panel on two airplanes with skin wrinkles found at two of the
external crack locations. We are issuing this AD to detect and
correct wrinkles and cracks in certain external skin panels of
section 48, which could join together and result in reduced
structural integrity of support structure for the vertical and
horizontal stabilizers and inability of the airplane to sustain
limit loads.
Compliance
(e) Comply with this AD within the compliance times specified,
unless already done.
Repetitive Inspections/Investigative and Corrective Actions
(f) At the applicable compliance times specified in paragraph
1.E., ``Compliance'' of Boeing Alert Service Bulletin 777-53A0051,
dated November 8, 2007, except as provided by paragraph (g) of this
AD: Do the applicable inspections for any wrinkle of the external
skin and for cracking at the fuselage bulkhead shear tie end
fastener locations at Stations 2195.75, 2221.65, and 2245.70 of the
section 48 panel of the fuselage, between stringers 5 and 10 on the
left and right sides; and do all the applicable investigative and
corrective actions; by doing all of the applicable actions in
accordance with the Accomplishment Instructions of the service
bulletin, except as provided by paragraph (h) of this AD. Do all
applicable investigative and corrective actions before further
flight. Repeat the applicable inspections thereafter at the
applicable intervals specified in paragraph 1.E. of the service
bulletin.
Exception to Compliance Times
(g) Where Boeing Alert Service Bulletin 777-53A0051, dated
November 8, 2007, specifies counting the compliance time from ``* *
* the date on this service bulletin,'' this AD requires counting the
compliance time from the effective date of this AD.
Exception to Corrective Actions
(h) If any damage beyond the repair limits specified in Boeing
Alert Service Bulletin 777-53A0051, dated November 8, 2007, is found
during any inspection required by this AD, and the service bulletin
specifies to contact Boeing for appropriate action: Before further
flight, repair the crack using a method approved in accordance with
the procedures specified in paragraph (i) of this AD.
Alternative Methods of Compliance (AMOCs)
(i)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, ATTN: Duong Tran, Aerospace Engineer, Airframe Branch, ANM-
120S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington
98057-3356; telephone (425) 917-6452; fax (425) 917-6590 has the
authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19.
(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 appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
(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
Delegation Option Authorization Organization who has been authorized
by the Manager, Seattle ACO, to make those findings. For a repair
method to be approved, the repair must meet the certification basis
of the airplane.
Issued in Renton, Washington, on April 25, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-10059 Filed 5-6-08; 8:45 am]
BILLING CODE 4910-13-P
