Airworthiness Directives; Boeing Model 747 Airplanes, 32246-32248 [E8-12712]
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32246
Federal Register / Vol. 73, No. 110 / Friday, June 6, 2008 / Proposed Rules
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:
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–2008–0619;
Directorate Identifier 2007–NM–356–AD.
system, which could result in multi-engine
flameout, inability to restart the engines, and
consequent forced landing of the airplane.
Compliance
(e) Comply with this AD within the
compliance times specified, unless already
done.
Operational Test/Other Related Testing
(f) Within 30,000 flight hours after the
effective date of this AD, perform an
operational test of the engine fuel suction
feed of the fuel system, and perform all other
related testing, as applicable, before further
flight, according to a method approved by the
Manager, Seattle Aircraft Certification Office
(ACO), FAA. One approved method is the
operational test in Section 28–22–00, titled
‘‘Engine Fuel Feed System—Description and
Operation,’’ of the Boeing 747 Maintenance
Manual; and Boeing 747 Task Card 4–28–
007–05, titled ‘‘Engine Fuel Suction Feed
System,’’ dated April 25, 2007. Repeat the
operational test thereafter at intervals not to
exceed 30,000 flight hours. Thereafter, except
as provided in paragraph (g) of this AD, no
alternative procedure or repeat test intervals
will be allowed.
Alternative Methods of Compliance
(AMOCs)
(g)(1) The Manager, Seattle ACO, FAA,
ATTN: Sue Lucier, Aerospace Engineer,
Propulsion Branch, ANM–140S, 1601 Lind
Avenue, SW., Renton, Washington 98057–
3356; telephone (425) 917–6438; 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.
Issued in Renton, Washington, on June 2,
2008.
Michael J. Kaszycki,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. E8–12692 Filed 6–5–08; 8:45 am]
BILLING CODE 4910–13–P
Affected ADs
(b) None.
dwashington3 on PRODPC61 with PROPOSALS
Comments Due Date
(a) We must receive comments by July 21,
2008.
DEPARTMENT OF TRANSPORTATION
Applicability
(c) This AD applies to Boeing Model 747–
100, 747–100B, 747–100B SUD, 747–200B,
747–200C, 747–200F, 747–300, 747SR, and
747SP series airplanes, certificated in any
category.
Federal Aviation Administration
Unsafe Condition
(d) This AD results from a report of inservice occurrences of loss of fuel system
suction feed capability, followed by total loss
of pressure of the fuel feed system. We are
issuing this AD to detect and correct failure
of the engine fuel suction feed of the fuel
RIN 2120–AA64
VerDate Aug<31>2005
11:59 Jun 05, 2008
Jkt 214001
14 CFR Part 39
[Docket No. FAA–2008–0612; Directorate
Identifier 2008–NM–059–AD]
Airworthiness Directives; Boeing
Model 747 Airplanes
Federal Aviation
Administration (FAA), DOT.
AGENCY:
PO 00000
Frm 00004
Fmt 4702
Sfmt 4702
Notice of proposed rulemaking
(NPRM).
ACTION:
SUMMARY: We propose to adopt a new
airworthiness directive (AD) for all
Boeing Model 747 airplanes. This
proposed AD would require inspecting
for cracks in the left- and right-side
Stringer 11 longeron adjacent to the
horizontal stabilizer pivot bulkhead,
and related investigative and corrective
actions if necessary. This proposed AD
results from a report of a crack found in
the right-side Stringer 11 longeron
horizontal flange, adjacent to the
horizontal stabilizer pivot bulkhead,
during a routine maintenance
inspection. We are proposing this AD to
detect and correct fatigue cracking of the
longeron, which can propagate and
cause damage to the adjacent horizontal
stabilizer pivot bulkhead. This damage
could result in loss of structural
integrity and consequent inability of the
bulkhead to carry flight loads, which
could adversely affect controllability of
the airplane.
DATES: We must receive comments on
this proposed AD by July 21, 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: Ivan
Li, Aerospace Engineer, Airframe
E:\FR\FM\06JNP1.SGM
06JNP1
Federal Register / Vol. 73, No. 110 / Friday, June 6, 2008 / Proposed Rules
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–2008–0612; Directorate Identifier
2008–NM–059–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.
dwashington3 on PRODPC61 with PROPOSALS
Discussion
We received a report of a crack found
in the right-side Stringer 11 longeron
horizontal flange, adjacent to the
horizontal stabilizer pivot bulkhead,
during a routine maintenance
inspection. The airplane had
accumulated 28,311 total flight hours
and 22,070 total flight cycles. The crack
was visible in the exposed inboard edge
of the longeron horizontal flange
between the upper and lower Station
2598 horizontal stabilizer pivot
bulkhead splice fittings. After removal
of the fittings it was revealed that the
crack had propagated and completely
severed the longeron. Boeing analysis
indicates that the severed longeron was
a result of fatigue that had originated
from a fastener hole in the longeron
horizontal flange. Fatigue cracking of
the longeron can propagate and cause
damage to the adjacent horizontal
stabilizer pivot bulkhead. This
condition, if not corrected, could result
in loss of structural integrity and
consequent inability of the bulkhead to
carry flight loads, which could
adversely affect controllability of the
airplane.
Relevant Service Information
We have reviewed Boeing Alert
Service Bulletin 747–53A2703, dated
February 14, 2008. The service bulletin
describes procedures for a surface high
frequency eddy current (HFEC)
inspection for cracks in the left- and
VerDate Aug<31>2005
11:59 Jun 05, 2008
Jkt 214001
right-side Stringer 11 longeron exposed
surfaces and edges between Stations
2598 and 2607 adjacent to the
horizontal stabilizer pivot bulkhead,
and related investigative and corrective
actions if necessary. The procedures for
the related investigative and corrective
actions are as follows:
• If any crack is found during the
surface HFEC inspection: The
procedures describe doing a detailed
inspection for cracks in the adjacent
skin panel and Station 2598 of the
horizontal stabilizer pivot bulkhead
structure. If any crack is found in the
skin panel or bulkhead structure, the
crack may be repaired as specified in
the 747 structural repair manual, or
contact Boeing for repair data and
repair. After the repair is installed, the
longeron is replaced with a new
longeron.
• If no crack is found during the
surface HFEC inspection: The
procedures describe doing an open hole
HFEC inspection of the longeron for
cracks at the specified fastener hole
locations.
• If any crack is found during the
open hole HFEC inspection: The
procedures describe oversizing any
cracked hole to remove the crack, and
the inspection is repeated for any
remaining cracks. If any crack remains
after oversizing the hole to the
maximum allowed diameter, the
longeron is removed and a detailed
inspection is done for cracks in the
adjacent skin panel and Station 2598 of
the horizontal stabilizer pivot bulkhead
structure. If any crack is found in the
skin panel or bulkhead structure, the
crack is repaired as specified in the 747
structural repair manual, or the
procedures recommend contacting
Boeing for repair data and repair. After
the repair is installed, the longeron is
replaced with a new longeron. If no
crack is found, a new longeron is
installed.
The compliance times for the actions
in the service bulletin are as follows:
• The compliance time for the initial
surface HFEC inspection is before the
accumulation of 20,000 total flight
cycles, or within 1,500 flight cycles after
the date on the service bulletin,
whichever occurs later. If a new
longeron is installed, the inspection is
repeated before the accumulation of
20,000 flight cycles after the
installation. If a longeron is repaired, or
if no crack is found during the surface
and open hole HFEC inspections, the
applicable inspection is repeated at
intervals not to exceed 3,000 flight
cycles after the repair is done.
The related investigative and
corrective actions are to be done before
PO 00000
Frm 00005
Fmt 4702
Sfmt 4702
32247
further flight after the surface HFEC
inspections are done. The above
compliance times and actions apply to
the left and right side longerons,
independently.
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 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 this proposed AD
would affect 165 airplanes of U.S.
registry. We also estimate that it would
take 3 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 $39,600, or $240 per
product.
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
E:\FR\FM\06JNP1.SGM
06JNP1
32248
Federal Register / Vol. 73, No. 110 / Friday, June 6, 2008 / Proposed Rules
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:
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–2008–0612;
Directorate Identifier 2008–NM–059–AD.
dwashington3 on PRODPC61 with PROPOSALS
Comments Due Date
(a) We must receive comments by July 21,
2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to all Boeing Model
747–100, 747–100B, 747–100B SUD, 747–
200B, 747–200C, 747–200F, 747–300, 747–
400, 747–400D, 747–400F, 747SR, and 747SP
series airplanes, certificated in any category.
VerDate Aug<31>2005
11:59 Jun 05, 2008
Jkt 214001
Unsafe Condition
(d) This AD results from a report of a crack
found in the right-side Stringer 11 longeron
horizontal flange, adjacent to the horizontal
stabilizer pivot bulkhead, during a routine
maintenance inspection. We are issuing this
AD to detect and correct fatigue cracking of
the longeron, which can propagate and cause
damage to the adjacent horizontal stabilizer
pivot bulkhead. This damage could result in
loss of structural integrity and consequent
inability of the bulkhead to carry flight loads,
which could adversely affect controllability
of the airplane.
Compliance
(e) Comply with this AD within the
compliance times specified, unless already
done.
Inspection/Related Investigative and
Corrective Actions
(f) Except as provided by paragraph (g) of
this AD: At the applicable times specified in
paragraph 1.E. of Boeing Alert Service
Bulletin 747–53A2703, dated February 14,
2008, do a surface high frequency eddy
current (HFEC) inspection for cracks in the
left- and right-side Stringer 11 longeron
exposed surfaces and edges between Station
2598 and 2607 adjacent to the horizontal
stabilizer pivot bulkhead; and do all
applicable related investigative and
corrective actions before further flight, in
accordance with the Accomplishment
Instructions of the service bulletin, except as
provided by paragraph (h) of this AD.
Exception to Compliance Times
(g) Where Boeing Alert Service Bulletin
747–53A2703, dated February 14, 2008,
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 crack is found during any
inspection required by this AD, and Boeing
Alert Service Bulletin 747–53A2703, dated
February 14, 2008, specifies to contact
Boeing for appropriate action: Before further
flight, repair 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: Ivan
Li, Aerospace Engineer, Airframe Branch,
ANM–120S, FAA, Seattle ACO, 1601 Lind
Avenue, SW., Renton, Washington 98057–
3356; telephone (425) 917–6437; 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.
PO 00000
Frm 00006
Fmt 4702
Sfmt 4702
(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 May 29,
2008.
Ali Bahrami,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. E8–12712 Filed 6–5–08; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2008–0620; Directorate
Identifier 2007–NM–357–AD]
RIN 2120–AA64
Airworthiness Directives; Boeing
Model 747–400, –400D, and –400F
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 747–400, –400D, and
–400F series airplanes. This proposed
AD would require performing repetitive
operational tests of the engine fuel
suction feed of the fuel system, and
other related testing if necessary. This
proposed AD results from a report of inservice occurrences of loss of fuel
system suction feed capability, followed
by total loss of pressure of the fuel feed
system. We are proposing this AD to
detect and correct failure of the engine
fuel suction feed of the fuel system,
which could result in multi-engine
flameout, inability to restart the engines,
and consequent forced landing of the
airplane.
DATES: We must receive comments on
this proposed AD by July 21, 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.
E:\FR\FM\06JNP1.SGM
06JNP1
Agencies
[Federal Register Volume 73, Number 110 (Friday, June 6, 2008)]
[Proposed Rules]
[Pages 32246-32248]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-12712]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-0612; Directorate Identifier 2008-NM-059-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: We propose to adopt a new airworthiness directive (AD) for all
Boeing Model 747 airplanes. This proposed AD would require inspecting
for cracks in the left- and right-side Stringer 11 longeron adjacent to
the horizontal stabilizer pivot bulkhead, and related investigative and
corrective actions if necessary. This proposed AD results from a report
of a crack found in the right-side Stringer 11 longeron horizontal
flange, adjacent to the horizontal stabilizer pivot bulkhead, during a
routine maintenance inspection. We are proposing this AD to detect and
correct fatigue cracking of the longeron, which can propagate and cause
damage to the adjacent horizontal stabilizer pivot bulkhead. This
damage could result in loss of structural integrity and consequent
inability of the bulkhead to carry flight loads, which could adversely
affect controllability of the airplane.
DATES: We must receive comments on this proposed AD by July 21, 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: Ivan Li, Aerospace Engineer, Airframe
[[Page 32247]]
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-2008-0612;
Directorate Identifier 2008-NM-059-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 received a report of a crack found in the right-side Stringer 11
longeron horizontal flange, adjacent to the horizontal stabilizer pivot
bulkhead, during a routine maintenance inspection. The airplane had
accumulated 28,311 total flight hours and 22,070 total flight cycles.
The crack was visible in the exposed inboard edge of the longeron
horizontal flange between the upper and lower Station 2598 horizontal
stabilizer pivot bulkhead splice fittings. After removal of the
fittings it was revealed that the crack had propagated and completely
severed the longeron. Boeing analysis indicates that the severed
longeron was a result of fatigue that had originated from a fastener
hole in the longeron horizontal flange. Fatigue cracking of the
longeron can propagate and cause damage to the adjacent horizontal
stabilizer pivot bulkhead. This condition, if not corrected, could
result in loss of structural integrity and consequent inability of the
bulkhead to carry flight loads, which could adversely affect
controllability of the airplane.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 747-53A2703, dated
February 14, 2008. The service bulletin describes procedures for a
surface high frequency eddy current (HFEC) inspection for cracks in the
left- and right-side Stringer 11 longeron exposed surfaces and edges
between Stations 2598 and 2607 adjacent to the horizontal stabilizer
pivot bulkhead, and related investigative and corrective actions if
necessary. The procedures for the related investigative and corrective
actions are as follows:
If any crack is found during the surface HFEC inspection:
The procedures describe doing a detailed inspection for cracks in the
adjacent skin panel and Station 2598 of the horizontal stabilizer pivot
bulkhead structure. If any crack is found in the skin panel or bulkhead
structure, the crack may be repaired as specified in the 747 structural
repair manual, or contact Boeing for repair data and repair. After the
repair is installed, the longeron is replaced with a new longeron.
If no crack is found during the surface HFEC inspection:
The procedures describe doing an open hole HFEC inspection of the
longeron for cracks at the specified fastener hole locations.
If any crack is found during the open hole HFEC
inspection: The procedures describe oversizing any cracked hole to
remove the crack, and the inspection is repeated for any remaining
cracks. If any crack remains after oversizing the hole to the maximum
allowed diameter, the longeron is removed and a detailed inspection is
done for cracks in the adjacent skin panel and Station 2598 of the
horizontal stabilizer pivot bulkhead structure. If any crack is found
in the skin panel or bulkhead structure, the crack is repaired as
specified in the 747 structural repair manual, or the procedures
recommend contacting Boeing for repair data and repair. After the
repair is installed, the longeron is replaced with a new longeron. If
no crack is found, a new longeron is installed.
The compliance times for the actions in the service bulletin are as
follows:
The compliance time for the initial surface HFEC
inspection is before the accumulation of 20,000 total flight cycles, or
within 1,500 flight cycles after the date on the service bulletin,
whichever occurs later. If a new longeron is installed, the inspection
is repeated before the accumulation of 20,000 flight cycles after the
installation. If a longeron is repaired, or if no crack is found during
the surface and open hole HFEC inspections, the applicable inspection
is repeated at intervals not to exceed 3,000 flight cycles after the
repair is done.
The related investigative and corrective actions are to be done
before further flight after the surface HFEC inspections are done. The
above compliance times and actions apply to the left and right side
longerons, independently.
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 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 this proposed AD would affect 165 airplanes of
U.S. registry. We also estimate that it would take 3 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 $39,600, or $240 per product.
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
[[Page 32248]]
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:
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-2008-0612; Directorate Identifier 2008-NM-
059-AD.
Comments Due Date
(a) We must receive comments by July 21, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to all Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D,
747-400F, 747SR, and 747SP series airplanes, certificated in any
category.
Unsafe Condition
(d) This AD results from a report of a crack found in the right-
side Stringer 11 longeron horizontal flange, adjacent to the
horizontal stabilizer pivot bulkhead, during a routine maintenance
inspection. We are issuing this AD to detect and correct fatigue
cracking of the longeron, which can propagate and cause damage to
the adjacent horizontal stabilizer pivot bulkhead. This damage could
result in loss of structural integrity and consequent inability of
the bulkhead to carry flight loads, which could adversely affect
controllability of the airplane.
Compliance
(e) Comply with this AD within the compliance times specified,
unless already done.
Inspection/Related Investigative and Corrective Actions
(f) Except as provided by paragraph (g) of this AD: At the
applicable times specified in paragraph 1.E. of Boeing Alert Service
Bulletin 747-53A2703, dated February 14, 2008, do a surface high
frequency eddy current (HFEC) inspection for cracks in the left- and
right-side Stringer 11 longeron exposed surfaces and edges between
Station 2598 and 2607 adjacent to the horizontal stabilizer pivot
bulkhead; and do all applicable related investigative and corrective
actions before further flight, in accordance with the Accomplishment
Instructions of the service bulletin, except as provided by
paragraph (h) of this AD.
Exception to Compliance Times
(g) Where Boeing Alert Service Bulletin 747-53A2703, dated
February 14, 2008, 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 crack is found during any inspection required by this
AD, and Boeing Alert Service Bulletin 747-53A2703, dated February
14, 2008, specifies to contact Boeing for appropriate action: Before
further flight, repair 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: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S,
FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6437; 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 May 29, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-12712 Filed 6-5-08; 8:45 am]
BILLING CODE 4910-13-P