Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-200B, 747-200C, 747-200F, 747SR, and 747SP Series Airplanes, 30074-30078 [E6-8007]
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Federal Register / Vol. 71, No. 101 / Thursday, May 25, 2006 / Proposed Rules
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
Applicability
Air transportation, Aircraft, Aviation
safety, Safety.
(c) This AD applies to all Fokker Model
F.28 Mark 0070 and 0100 airplanes,
certificated in any category.
The Proposed Amendment
Unsafe Condition
Accordingly, under the authority
delegated to me by the Administrator,
the FAA proposes to amend 14 CFR part
39 as follows:
(d) This AD results from a report of
electrical sparks coming out of the flight deck
from a panel behind the left seat. We are
issuing this AD to prevent failure of the
sliding window heating element(s), due to
electrical overload, which could result in
smoke and fire in the cockpit.
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 Federal Aviation
Administration (FAA) amends § 39.13
by adding the following new
airworthiness directive (AD):
Fokker Services B.V.: Docket No. FAA–
2006–24868; Directorate Identifier 2006–
NM–103–AD.
Comments Due Date
(a) The FAA must receive comments on
this AD action by June 26, 2006.
Affected ADs
(b) None.
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.
Modification of Wiring Distribution
(f) Within 36 months after the effective
date of this AD, modify the wiring
distribution of the alternating current bus
transfer power system and the right-hand and
left-hand windshield anti-icing system, by
accomplishing all of the actions specified in
the Accomplishment Instructions of Fokker
Service Bulletin SBF100–30–027, dated May
9, 2005, as applicable; including Manual
Change Notification—Maintenance
Documentation MCNM F100–098, dated May
9, 2005; and including the drawings listed in
Table 1 of this AD. (To conform to certain
Office of the Federal Register requirements
for incorporating these materials by
reference, the table identifies the date of the
service bulletin for undated drawings.)
TABLE 1.—DRAWINGS INCLUDED IN FOKKER SERVICE BULLETIN SBF100–30–027
Drawing
W41043
W41043
W41249
W41249
W41249
W41249
W41249
Sheet
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
Alternative Methods of Compliance
(AMOCs)
(g)(1) The Manager, International Branch,
ANM–116, Transport Airplane Directorate,
FAA, has the authority to approve AMOCs
for this AD, if requested in accordance with
the procedures found in 14 CFR 39.19.
(2) Before using any AMOC approved in
accordance with § 39.19 on any airplane to
which the AMOC applies, notify the
appropriate principal inspector in the FAA
Flight Standards Certificate Holding District
Office.
Issued in Renton, Washington, on May 17,
2006.
Kevin M. Mullin,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. E6–8009 Filed 5–24–06; 8:45 am]
BILLING CODE 4910–13–P
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2006–24877; Directorate
Identifier 2005–NM–253–AD]
Airworthiness Directives; Boeing
Model 747–100, 747–100B, 747–200B,
747–200C, 747–200F, 747SR, and
747SP Series Airplanes
(h) Dutch airworthiness directive NL–
2005–009, dated June 30, 2005, also
addresses the subject of this AD.
15:43 May 24, 2006
Date
RIN 2120–AA64
Related Information
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Issue
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking
(NPRM).
AGENCY:
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Federal Register / Vol. 71, No. 101 / Thursday, May 25, 2006 / Proposed Rules
SUMMARY: The FAA proposes to
supersede an existing airworthiness
directive (AD) that applies to certain
Boeing Model 747 series airplanes. The
existing AD currently requires repetitive
inspections to detect cracks at certain
stringer fastener locations; and repair, if
necessary. For certain airplanes, the
existing AD requires a modification in
certain areas where reports indicate that
cracking was prevalent. This
modification terminates the repetitive
inspections only for those areas, and is
also an option for other airplanes
affected by the existing AD. This
proposed AD would require one-time
inspections at a reduced inspection
threshold of areas that may have
Alodine-coated rivets installed, and
repair if necessary. This proposed AD
results from a report of cracking
discovered in a skin lap joint that was
previously inspected using the eddy
current method. We are proposing this
AD to prevent rapid decompression of
the airplane due to disbonding and
subsequent cracking of the skin panels.
DATES: We must receive comments on
this proposed AD by July 10, 2006.
ADDRESSES: Use one of the following
addresses to submit comments on this
proposed AD.
• DOT Docket Web site: Go to https://
dms.dot.gov and follow the instructions
for sending your comments
electronically.
• Government-wide rulemaking Web
site: Go to https://www.regulations.gov
and follow the instructions for sending
your comments electronically.
• Mail: Docket Management Facility;
U.S. Department of Transportation, 400
Seventh Street, SW., Nassif Building,
room PL–401, Washington, DC 20590.
• Fax: (202) 493–2251.
• Hand Delivery: Room PL–401 on
the plaza level of the Nassif Building,
400 Seventh Street, SW., Washington,
DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
Contact Boeing Commercial
Airplanes, P.O. Box 3707, Seattle,
Washington 98124–2207, for service
information identified in this proposed
AD.
FOR FURTHER INFORMATION CONTACT:
Nicholas Kusz, Aerospace Engineer,
Airframe Branch, ANM–120S, FAA,
Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton,
Washington 98055–4056; telephone
(425) 917–6432; fax (425) 917–6590.
SUPPLEMENTARY INFORMATION:
comments to an address listed in the
section. Include the docket
number ‘‘Docket No. FAA–2006–24877;
Directorate Identifier 2005–NM–253–
AD’’ at the beginning of your comments.
We specifically invite comments on the
overall regulatory, economic,
environmental, and energy aspects of
the proposed AD. We will consider all
comments received by the closing date
and may amend the proposed AD in
light of those comments.
We will post all comments we
receive, without change, to https://
dms.dot.gov, including any personal
information you provide. We will also
post a report summarizing each
substantive verbal contact with FAA
personnel concerning this proposed AD.
Using the search function of that Web
site, anyone can find and read the
comments in any of our dockets,
including the name of the individual
who sent the comment (or signed the
comment on behalf of an association,
business, labor union, etc.). You may
review the DOT’s complete Privacy Act
Statement in the Federal Register
published on April 11, 2000 (65 FR
19477–78), or may can visit https://
dms.dot.gov.
Comments Invited
We invite you to submit any relevant
written data, views, or arguments
regarding this proposed AD. Send your
Actions Since Existing AD Was Issued
Since 1985, Boeing has incorporated
rivets coated with Alodine into
production fuselage aluminum skins
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ADDRESSES
Examining the Docket
You may examine the AD docket on
the Internet at https://dms.dot.gov, or in
person at the Docket Management
Facility office between 9 a.m. and 5
p.m., Monday through Friday, except
Federal holidays. The Docket
Management Facility office (telephone
(800) 647–5227) is located on the plaza
level of the Nassif Building at the DOT
street address stated in the ADDRESSES
section. Comments will be available in
the AD docket shortly after the Docket
Management System receives them.
Discussion
On December 3, 1990, we issued AD
90–26–10, amendment 39–6836 (55 FR
51401, December 14, 1990), for certain
Boeing Model 747 series airplanes. That
AD requires repetitive inspections to
detect cracks at certain stringer fastener
locations; and repair, if necessary. For
certain airplanes, AD 90–26–10 requires
a modification in certain areas where
reports indicate that cracking was
prevalent. This modification terminates
the repetitive inspections only for those
areas. That AD resulted from reports of
multiple longitudinal skin cracks. We
issued that AD to prevent rapid
decompression of the airplane.
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and post-production skin modification
kits. Alodine coating on rivets provides
a protective chemical conversion
coating, but also increases electrical
conductivity. Certain non-destructive
inspection (NDI) methods rely on
disruptions in the electromagnetic field
around cracks in metallic structures to
detect cracking. One such NDI method
is the sliding probe eddy current
inspection, which was one inspection
method required by AD 90–26–10.
Conductivity of the Alodine-coated rivet
could be strong enough to mask
cracking in the fastener hole during
eddy current inspections.
Since we issued AD 90–26–10,
cracking was discovered in a skin lap
joint that was previously inspected
using the eddy current method. The
cracking was discovered during a fullscale fatigue test on a Model 737
fuselage. The skin lap joints on Model
737 airplanes are similar to those on the
affected Model 747 airplanes.
The manufacturer has accomplished a
comprehensive study of the effect of
Alodine-coated rivets on all Boeing
Airplane models. Based on the critical
nature of the sliding probe eddy current
inspection method, this study indicates
that two existing ADs, AD 96–23–02 and
AD 90–26–10, require further
rulemaking. We are proposing this
NPRM to supersede AD 90–26–10, and
Docket No. FAA–2006–24865 to
supersede AD 96–23–02. In addition,
based on this study, the FAA does not
propose to issue other ADs related to
Alodine-coated rivets.
Relevant Service Information
We have reviewed Boeing Alert
Service Bulletin 747–53A2321, Revision
7, dated October 27, 2005 (the original
issue of Boeing Alert Service Bulletin
747–53A2321, dated October 31, 1989,
was referenced as the appropriate
source of service information for
accomplishing the required actions in
AD 90–26–10). Revision 7 of the alert
service bulletin describes the
procedures that were required by AD
90–26–10, and includes new procedures
for a one-time external detailed
inspection for cracking of the skin area
between the lap joints between stringer
6 and stringer 14, from body station 340
to 520, which is designated as Area 1 by
the original issue of Boeing Alert
Service Bulletin 747–53A2321; and a
new external high-frequency eddy
current inspection to ensure a thorough
inspection for cracking of the areas
where Alodine-coated rivets are
installed. Alodine-coated rivets may
have been installed within Area 1
during accomplishment of a
modification specified in Boeing Service
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Federal Register / Vol. 71, No. 101 / Thursday, May 25, 2006 / Proposed Rules
Bulletin 747–53–2275, which was
mandated by AD 90–06–06, amendment
39–6490 (55 FR 8374, March 7, 1990).
The modification installed external
doublers in a small portion of Area 1
and also replaced stringers throughout
Area 1. The fasteners used for the
stringer replacement and doubler
installation may have been Alodinecoated rivets. However, the service
bulletin excludes from this inspection
those areas covered by the modification
doublers. Accomplishing the actions
specified in the service information is
intended to adequately address the
unsafe condition.
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 90–26–
10 and would retain the requirements of
the existing AD. This proposed AD
would also require accomplishing the
actions specified in the alert service
bulletin described previously, except as
discussed under ‘‘Difference Between
the Proposed AD and the Alert Service
Bulletin.’’
Difference Between the Proposed AD
and the Alert Service Bulletin
Boeing Alert Service Bulletin 747–
53A2321, Revision 7, 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.
Changes to Existing AD
Paragraphs E. and F. of AD 90–26–10
allow for adjustment to the compliance
threshold by not counting the flight
cycles in which cabin differential
pressure is at 2.0 pounds per square
inch (psi) or less; or allow for
multiplication by an adjustment factor
based on continued mixed operation at
lower cabin pressure differentials. This
proposed AD would not allow those
adjustments. However, this proposed
AD states that operators may continue to
adjust the repetitive inspection interval
based on a lower cabin differential
pressure until the next scheduled
inspection. Thereafter, this proposed
AD would not allow such adjustment.
We have determined that an adjustment
of flight cycles due to a lower cabin
differential pressure is not substantiated
and will not be allowed for use in
determining the flight-cycle threshold
for this proposed AD. There have been
several instances on other in-service
issues where analytical rationales have
indicated that pressurization cycles of
less than 2.0 psi should not be counted.
However, when fleet records have been
examined, the airplanes engaged in such
operations have the same or greater
occurrences of crack findings compared
with those on which all pressurized
flights are counted. As a result, we
consider such matters based on all
available factors, including individual
operators’ specific maintenance
programs, technical rationale, and fleet
experience. We have found that such
provisions are applicable only to a small
number of operators that may not
pressurize their airplanes above 2.0 psi
in all their flights. We have determined
that the best way to handle such
circumstances is for operators to request
an AMOC in accordance with the
procedures in paragraph (n) of this
proposed AD, rather than by increasing
the complexity of the AD by addressing
each operator’s unique situation.
Boeing has received a Delegation
Option Authorization (DOA). We have
revised this proposed AD to delegate the
authority to approve an alternative
method of compliance for any repair
that would be required by this proposed
AD to the Authorized Representative for
the Boeing DOA Organization.
The ‘‘detailed visual inspection’’
specified in AD 90–26–10 is referred to
as a ‘‘detailed inspection’’ in this
proposed AD. We have included the
definition for a detailed inspection in a
note in the proposed AD.
We have revised the applicability to
identify the model designations as
published in the most recent type
certificate data sheet for the affected
model.
This proposed AD would retain
certain requirements of AD 90–26–10.
Since AD 90–26–10 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
Requirement in AD
90–26–10
Paragraph
Paragraph
Paragraph
Paragraph
Paragraph
A
C
D
E
F
..............
..............
..............
..............
..............
Corresponding
requirement in this
proposed AD
Paragraph
Paragraph
Paragraph
Paragraph
Paragraph
(f).
(g).
(h).
(i).
(j).
Costs of Compliance
There are about 132 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. This
proposed AD would affect about 59
airplanes of U.S. registry. The average
labor rate is $80 per work hour.
ESTIMATED COSTS
Action
Work hours
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Inspection (required by AD 90–26–
10).
Modification (required by AD 90–
26–10).
Inspection (new proposed action) ...
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
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Parts
Cost per airplane
48
None ...........
$3,840, per inspection cycle ............
$226,560, per inspection cycle.
620
69, 246 ........
118,846 ............................................
7,011,914.
48
None ...........
3,840, per inspection cycle ..............
226,560, per inspection cycle.
the FAA Administrator. Subtitle VII,
Aviation Programs, describes in more
detail the scope of the Agency’s
authority.
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Fleet cost
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
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Federal Register / Vol. 71, No. 101 / Thursday, May 25, 2006 / Proposed Rules
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, 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.
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§ 39.13
[Amended]
2. The Federal Aviation
Administration (FAA) amends § 39.13
by removing amendment 39–6836 (55
FR 51401, December 14, 1990) and
adding the following new airworthiness
directive (AD):
Boeing: Docket No. FAA–2006–24877;
Directorate Identifier 2005–NM–253–AD.
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Comments Due Date
(a) The FAA must receive comments on
this AD action by July 10, 2006.
Affected ADs
(b) This AD supersedes AD 90–26–10.
Applicability
(c) This AD applies to Boeing Model 747–
100, 747–100B, 747–200B, 747–200C, 747–
200F, 747SR, and 747SP series airplanes,
certificated in any category; line numbers 001
through 430 inclusive.
Unsafe Condition
(d) This AD results from a report of
cracking discovered in a skin lap joint that
was previously inspected using the eddy
current method. We are issuing this AD to
prevent rapid decompression of the airplane
due to disbonding and subsequent cracking
of the skin panels.
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.
Restatement of Certain Requirements of AD
90–26–10
Inspections
(f) Prior to the accumulation of 12,000
flight cycles or within the next 1,000 flight
cycles after January 22, 1991 (the effective
date of AD 90–26–10), whichever occurs
later, unless previously accomplished within
the last 1,000 flight cycles, conduct an
external detailed and external high frequency
eddy current (HFEC) inspection for cracks of
the fuselage skin from body station (BS) 220
to BS 520, left and right hand side of the
airplane between stringers (S)–6 and S–14,
excluding the skin lap joints, in accordance
with the Accomplishment Instructions of
Boeing Alert Service Bulletin 747–53A2321,
dated October 31, 1989; or Revision 7, dated
October 27, 2005. After the effective date of
this AD, only Revision 7 may be used. Doing
the inspections in this paragraph in
accordance with Revision 7 of the service
bulletin eliminates the need for doing the
actions in paragraph (k) of this AD. Repeat
the inspections thereafter at intervals not to
exceed 2,000 flight cycles until the
terminating modification in paragraph (g) of
this AD is done, except as provided by
paragraph (h) of this AD.
Note 1: For the purposes of this AD, a
detailed inspection is: ‘‘An intensive
examination of a specific item, installation,
or assembly to detect damage, failure, or
irregularity. Available lighting is normally
supplemented with a direct source of good
lighting at an intensity deemed appropriate.
Inspection aids such as mirror, magnifying
lenses, etc., may be necessary. Surface
cleaning and elaborate procedures may be
required.’’
Terminating Modification
(g) For airplanes line numbers 001 through
200, prior to the accumulation of 20,000 total
flight cycles, or within 48 months after
January 22, 1991, whichever occurs later:
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Perform the terminating modification of the
skin panel from BS 340 to BS 520, S–6 to S–
14, in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin
747–53A2321, dated October 31, 1989; or
Revision 7, dated October 27, 2005. After the
effective date of this AD, only Revision 7 may
be used. The modification consists of
replacing the skin panel with a new skin
panel which was manufactured utilizing the
improved hot phosphoric anodize bonding
process.
(h) Replacement of the skin panel required
by paragraph (g) of this AD constitutes
terminating action for the inspections from
BS 340 to BS 520 required by paragraphs (f)
and (k) of this AD. The inspections from BS
220 to BS 340 required by paragraph (f) of
this AD are to be continued.
Adjustments for Cabin Differential Pressure
(i) Before the effective date of this AD:
Flight cycles conducted at 2.0 pounds per
square inch (psi) or less cabin differential
pressure need not be counted for the purpose
of this airworthiness directive.
(j) Before the effective date of this AD: For
Model 747SR airplanes only, the threshold
and repetitive inspection intervals specified
herein may be multiplied by the 1.2
adjustment factor based on continued mixed
operation at lower cabin pressure
differentials.
New Requirements of This AD
Inspections of Skins With Alodine-Coated
Rivets
(k) For airplanes identified in Figure 9 of
the Accomplishment Instructions of Boeing
Alert Service Bulletin 747–53A2321,
Revision 7, dated October 27, 2005, as
requiring additional inspection: Within 150
flight cycles after the effective date of this
AD, do the inspection in paragraph (k)(1) or
(k)(2) of this AD in accordance with the
Accomplishment Instructions of the service
bulletin.
(1) Do an external detailed inspection for
cracking of Area 1, and repeat the inspection
thereafter at intervals not to exceed 150 flight
cycles until one of the actions in paragraph
(k)(1)(i), (k)(1)(ii), or (k)(1)(iii) is
accomplished. Repeat the inspection of Area
1 thereafter in accordance with the
requirements of paragraph (f) of this AD.
(i) The inspection in accordance with
paragraph (k)(1) of this AD has been done
seven times at intervals not to exceed 150
flight cycles. If this option is used: Within
150 flight cycles after the seventh inspection,
do the inspection required by paragraph
(k)(2) of this AD.
(ii) The inspection in accordance with
paragraph (k)(2) has been accomplished.
(iii) The inspections in accordance with
paragraph (f) of this AD has been
accomplished once in accordance with
Revision 7 of the service bulletin.
(2) Do an external HFEC inspection for
cracking of Area 1 in accordance with the
Accomplishment Instructions of Boeing Alert
Service Bulletin 747–53A2321, Revision 7,
dated October 27, 2005. Repeat the HFEC
inspection of Area 1 thereafter in accordance
with the requirements of paragraph (f) of this
AD.
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Repair
(l) If any crack is found during any
inspection required by this AD: Before
further flight, repair in accordance with the
Accomplishment Instructions of Boeing Alert
Service Bulletin 747–53A2321, dated October
31, 1989; or Revision 7, dated October 27,
2005. After the effective date of this AD, only
Revision 7 of the service bulletin may be
used. Where Revision 7 of the service
bulletin specifies to contact Boeing for repair
instructions: Before further flight, repair
using a method approved in accordance with
the procedures specified in paragraph (n) of
this AD.
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Adjustments to Compliance Time: Cabin
Differential Pressure
(m) For the purposes of calculating the
compliance threshold and repetitive interval
for actions required by paragraph (f), (g), and
(k) of this AD, on or after the effective date
of this AD: All flight cycles, including the
number of flight cycles in which cabin
differential pressure is at 2.0 psi or less, must
be counted when determining the number of
flight cycles that have occurred on the
airplane, and a 1.2 adjustment factor may not
be used. However, for airplanes on which the
repetitive interval for the actions required by
paragraphs (f) and (k) of this AD have been
calculated in accordance with paragraph (i)
or (j) of this AD by excluding the number of
flight cycles in which cabin differential
pressure is at 2.0 pounds psi or less, or by
using a 1.2 adjustment factor: Continue to
adjust the repetitive interval in accordance
with paragraph (i) or (j) of this AD until the
next inspections required by paragraph (f) or
(k) of this AD are accomplished. Thereafter,
no adjustment to compliance times based on
paragraph (i) or (j) of this AD is allowed.
Alternative Methods of Compliance (AMOCs)
(n)(1) The Manager, Seattle Aircraft
Certification Office (ACO), FAA, has the
authority to approve AMOCs for this AD, if
requested in accordance with the procedures
found in 14 CFR 39.19.
(2) Before using any AMOC approved in
accordance with § 39.19 on any airplane to
which the AMOC applies, notify the
appropriate principal inspector in the FAA
Flight Standards Certificate Holding District
Office.
(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.
(4) AMOCs approved previously in
accordance with AD 90–26–10 are acceptable
for compliance with the requirements of this
AD, provided that any alternative terminating
action was not based upon inspection results
using sliding probe low-frequency eddy
current (LFEC), sliding probe HFEC, or midfrequency eddy current (MFEC) inspection
method; and provided that any alternative
method future inspections did not
incorporate sliding probe LFEC or MFEC
inspection method.
VerDate Aug<31>2005
15:43 May 24, 2006
Jkt 208001
Issued in Renton, Washington, on May 16,
2006.
Kevin M. Mullin,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. E6–8007 Filed 5–24–06; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2006–24785; Directorate
Identifier 2006–NE–20–AD]
RIN 2120–AA64
Airworthiness Directives; Lycoming
Engines (L)O–360, (L)IO–360, AEIO–
360, O–540, IO–540, AEIO–540, (L)TIO–
540, IO–580, AEIO–580, and IO–720
Series Reciprocating Engines
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking
(NPRM).
AGENCY:
SUMMARY: The FAA proposes to adopt a
new airworthiness directive (AD) for
certain Lycoming Engines (L)O–360,
(L)IO–360, AEIO–360, O–540, IO–540,
AEIO–540, (L)TIO–540, IO–580, AEIO–
580, and IO–720 series reciprocating
engines. This proposed AD would
require replacing certain crankshafts.
This proposed AD results from reports
of 23 confirmed failures of similar
crankshafts in Lycoming Engines 360
and 540 series reciprocating engines.
We are proposing this AD to prevent
failure of the crankshaft, which will
result in total engine power loss, inflight engine failure, and possible loss of
the aircraft.
DATES: We must receive any comments
on this proposed AD by June 26, 2006.
ADDRESSES: Use one of the following
addresses to comment on this proposed
AD.
• DOT Docket Web site: Go to https://
dms.dot.gov and follow the instructions
for sending your comments
electronically.
• Government-wide rulemaking Web
site: Go to https://www.regulations.gov
and follow the instructions for sending
your comments electronically.
• Mail: Docket Management Facility;
U.S. Department of Transportation, 400
Seventh Street, SW., Nassif Building,
Room PL–401, Washington, DC 20590–
0001.
• Fax: (202) 493–2251.
• Hand Delivery: Room PL–401 on
the plaza level of the Nassif Building,
PO 00000
Frm 00010
Fmt 4702
Sfmt 4702
400 Seventh Street, SW., Washington,
DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
You can get the service information
identified in this proposed AD from
Lycoming, 652 Oliver Street,
Williamsport, PA 17701; telephone
(570) 323–6181; fax (570) 327–7101, or
on the Internet at https://
www.Lycoming.Textron.com.
You may examine the comments on
this proposed AD in the AD docket on
the Internet at https://dms.dot.gov.
FOR FURTHER INFORMATION CONTACT:
Norm Perenson, Aerospace Engineer,
New York Aircraft Certification Office,
FAA, Engine & Propeller Directorate,
1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; telephone (516)
228–7337; fax (516) 794–5531.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send us any written
relevant data, views, or arguments
regarding this proposal. Send your
comments to an address listed under
ADDRESSES. Include ‘‘Docket No. FAA–
2006–24785; Directorate Identifier
2006–NE–20–AD’’ in the subject line of
your comments. We specifically invite
comments on the overall regulatory,
economic, environmental, and energy
aspects of the proposed AD. We will
consider all comments received by the
closing date and may amend the
proposed AD in light of those
comments.
We will post all comments we
receive, without change, to https://
dms.dot.gov, including any personal
information you provide. We will also
post a report summarizing each
substantive verbal contact with FAA
personnel concerning this proposed AD.
Using the search function of the DOT
Web site, anyone can find and read the
comments in any of our dockets. This
includes the name of the individual
who sent the comment (or signed the
comment on behalf of an association,
business, labor union, etc.). You may
review the DOT’s complete Privacy Act
Statement in the Federal Register
published on April 11, 2000 (65 FR
19477–78) or you may visit https://
dms.dot.gov.
Examining the AD Docket
You may examine the docket that
contains the proposal, any comments
received and, any final disposition in
person at the DOT Docket Office
between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
The Docket Office (telephone (800) 647–
5227) is located on the plaza level of the
Department of Transportation Nassif
E:\FR\FM\25MYP1.SGM
25MYP1
]]>Agencies
[Federal Register Volume 71, Number 101 (Thursday, May 25, 2006)]
[Proposed Rules]
[Pages 30074-30078]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-8007]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2006-24877; Directorate Identifier 2005-NM-253-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
200B, 747-200C, 747-200F, 747SR, and 747SP Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
[[Page 30075]]
SUMMARY: The FAA proposes to supersede an existing airworthiness
directive (AD) that applies to certain Boeing Model 747 series
airplanes. The existing AD currently requires repetitive inspections to
detect cracks at certain stringer fastener locations; and repair, if
necessary. For certain airplanes, the existing AD requires a
modification in certain areas where reports indicate that cracking was
prevalent. This modification terminates the repetitive inspections only
for those areas, and is also an option for other airplanes affected by
the existing AD. This proposed AD would require one-time inspections at
a reduced inspection threshold of areas that may have Alodine-coated
rivets installed, and repair if necessary. This proposed AD results
from a report of cracking discovered in a skin lap joint that was
previously inspected using the eddy current method. We are proposing
this AD to prevent rapid decompression of the airplane due to
disbonding and subsequent cracking of the skin panels.
DATES: We must receive comments on this proposed AD by July 10, 2006.
ADDRESSES: Use one of the following addresses to submit comments on
this proposed AD.
DOT Docket Web site: Go to https://dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to https://
www.regulations.gov and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility; U.S. Department of
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401,
Washington, DC 20590.
Fax: (202) 493-2251.
Hand Delivery: Room PL-401 on the plaza level of the
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207, for service information identified in this
proposed AD.
FOR FURTHER INFORMATION CONTACT: Nicholas Kusz, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6432; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any relevant written data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed in the ADDRESSES section. Include the docket number ``Docket No.
FAA-2006-24877; Directorate Identifier 2005-NM-253-AD'' at the
beginning of your comments. We specifically invite comments on the
overall regulatory, economic, environmental, and energy aspects of the
proposed AD. We will consider all comments received by the closing date
and may amend the proposed AD in light of those comments.
We will post all comments we receive, without change, to https://
dms.dot.gov, including any personal information you provide. We will
also post a report summarizing each substantive verbal contact with FAA
personnel concerning this proposed AD. Using the search function of
that Web site, anyone can find and read the comments in any of our
dockets, including the name of the individual who sent the comment (or
signed the comment on behalf of an association, business, labor union,
etc.). You may review the DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78), or may
can visit https://dms.dot.gov.
Examining the Docket
You may examine the AD docket on the Internet at https://
dms.dot.gov, or in person at the Docket Management Facility office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT
street address stated in the ADDRESSES section. Comments will be
available in the AD docket shortly after the Docket Management System
receives them.
Discussion
On December 3, 1990, we issued AD 90-26-10, amendment 39-6836 (55
FR 51401, December 14, 1990), for certain Boeing Model 747 series
airplanes. That AD requires repetitive inspections to detect cracks at
certain stringer fastener locations; and repair, if necessary. For
certain airplanes, AD 90-26-10 requires a modification in certain areas
where reports indicate that cracking was prevalent. This modification
terminates the repetitive inspections only for those areas. That AD
resulted from reports of multiple longitudinal skin cracks. We issued
that AD to prevent rapid decompression of the airplane.
Actions Since Existing AD Was Issued
Since 1985, Boeing has incorporated rivets coated with Alodine into
production fuselage aluminum skins and post-production skin
modification kits. Alodine coating on rivets provides a protective
chemical conversion coating, but also increases electrical
conductivity. Certain non-destructive inspection (NDI) methods rely on
disruptions in the electromagnetic field around cracks in metallic
structures to detect cracking. One such NDI method is the sliding probe
eddy current inspection, which was one inspection method required by AD
90-26-10. Conductivity of the Alodine-coated rivet could be strong
enough to mask cracking in the fastener hole during eddy current
inspections.
Since we issued AD 90-26-10, cracking was discovered in a skin lap
joint that was previously inspected using the eddy current method. The
cracking was discovered during a full-scale fatigue test on a Model 737
fuselage. The skin lap joints on Model 737 airplanes are similar to
those on the affected Model 747 airplanes.
The manufacturer has accomplished a comprehensive study of the
effect of Alodine-coated rivets on all Boeing Airplane models. Based on
the critical nature of the sliding probe eddy current inspection
method, this study indicates that two existing ADs, AD 96-23-02 and AD
90-26-10, require further rulemaking. We are proposing this NPRM to
supersede AD 90-26-10, and Docket No. FAA-2006-24865 to supersede AD
96-23-02. In addition, based on this study, the FAA does not propose to
issue other ADs related to Alodine-coated rivets.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 747-53A2321,
Revision 7, dated October 27, 2005 (the original issue of Boeing Alert
Service Bulletin 747-53A2321, dated October 31, 1989, was referenced as
the appropriate source of service information for accomplishing the
required actions in AD 90-26-10). Revision 7 of the alert service
bulletin describes the procedures that were required by AD 90-26-10,
and includes new procedures for a one-time external detailed inspection
for cracking of the skin area between the lap joints between stringer 6
and stringer 14, from body station 340 to 520, which is designated as
Area 1 by the original issue of Boeing Alert Service Bulletin 747-
53A2321; and a new external high-frequency eddy current inspection to
ensure a thorough inspection for cracking of the areas where Alodine-
coated rivets are installed. Alodine-coated rivets may have been
installed within Area 1 during accomplishment of a modification
specified in Boeing Service
[[Page 30076]]
Bulletin 747-53-2275, which was mandated by AD 90-06-06, amendment 39-
6490 (55 FR 8374, March 7, 1990). The modification installed external
doublers in a small portion of Area 1 and also replaced stringers
throughout Area 1. The fasteners used for the stringer replacement and
doubler installation may have been Alodine-coated rivets. However, the
service bulletin excludes from this inspection those areas covered by
the modification doublers. Accomplishing the actions specified in the
service information is intended to adequately address the unsafe
condition.
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 90-26-10 and would retain the requirements of the
existing AD. This proposed AD would also require accomplishing the
actions specified in the alert service bulletin described previously,
except as discussed under ``Difference Between the Proposed AD and the
Alert Service Bulletin.''
Difference Between the Proposed AD and the Alert Service Bulletin
Boeing Alert Service Bulletin 747-53A2321, Revision 7, 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.
Changes to Existing AD
Paragraphs E. and F. of AD 90-26-10 allow for adjustment to the
compliance threshold by not counting the flight cycles in which cabin
differential pressure is at 2.0 pounds per square inch (psi) or less;
or allow for multiplication by an adjustment factor based on continued
mixed operation at lower cabin pressure differentials. This proposed AD
would not allow those adjustments. However, this proposed AD states
that operators may continue to adjust the repetitive inspection
interval based on a lower cabin differential pressure until the next
scheduled inspection. Thereafter, this proposed AD would not allow such
adjustment. We have determined that an adjustment of flight cycles due
to a lower cabin differential pressure is not substantiated and will
not be allowed for use in determining the flight-cycle threshold for
this proposed AD. There have been several instances on other in-service
issues where analytical rationales have indicated that pressurization
cycles of less than 2.0 psi should not be counted. However, when fleet
records have been examined, the airplanes engaged in such operations
have the same or greater occurrences of crack findings compared with
those on which all pressurized flights are counted. As a result, we
consider such matters based on all available factors, including
individual operators' specific maintenance programs, technical
rationale, and fleet experience. We have found that such provisions are
applicable only to a small number of operators that may not pressurize
their airplanes above 2.0 psi in all their flights. We have determined
that the best way to handle such circumstances is for operators to
request an AMOC in accordance with the procedures in paragraph (n) of
this proposed AD, rather than by increasing the complexity of the AD by
addressing each operator's unique situation.
Boeing has received a Delegation Option Authorization (DOA). We
have revised this proposed AD to delegate the authority to approve an
alternative method of compliance for any repair that would be required
by this proposed AD to the Authorized Representative for the Boeing DOA
Organization.
The ``detailed visual inspection'' specified in AD 90-26-10 is
referred to as a ``detailed inspection'' in this proposed AD. We have
included the definition for a detailed inspection in a note in the
proposed AD.
We have revised the applicability to identify the model
designations as published in the most recent type certificate data
sheet for the affected model.
This proposed AD would retain certain requirements of AD 90-26-10.
Since AD 90-26-10 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
------------------------------------------------------------------------
Corresponding requirement
Requirement in AD 90-26-10 in this proposed AD
------------------------------------------------------------------------
Paragraph A............................... Paragraph (f).
Paragraph C............................... Paragraph (g).
Paragraph D............................... Paragraph (h).
Paragraph E............................... Paragraph (i).
Paragraph F............................... Paragraph (j).
------------------------------------------------------------------------
Costs of Compliance
There are about 132 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. This proposed AD would
affect about 59 airplanes of U.S. registry. The average labor rate is
$80 per work hour.
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Action Work hours Parts Cost per airplane Fleet cost
----------------------------------------------------------------------------------------------------------------
Inspection (required by AD 90-26- 48 None................. $3,840, per $226,560, per
10). inspection cycle. inspection cycle.
Modification (required by AD 90- 620 69, 246.............. 118,846............ 7,011,914.
26-10).
Inspection (new proposed action). 48 None................. 3,840, per 226,560, per
inspection cycle. 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
[[Page 30077]]
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, 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 Federal Aviation Administration (FAA) amends Sec. 39.13 by
removing amendment 39-6836 (55 FR 51401, December 14, 1990) and adding
the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2006-24877; Directorate Identifier 2005-NM-
253-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by July 10,
2006.
Affected ADs
(b) This AD supersedes AD 90-26-10.
Applicability
(c) This AD applies to Boeing Model 747-100, 747-100B, 747-200B,
747-200C, 747-200F, 747SR, and 747SP series airplanes, certificated
in any category; line numbers 001 through 430 inclusive.
Unsafe Condition
(d) This AD results from a report of cracking discovered in a
skin lap joint that was previously inspected using the eddy current
method. We are issuing this AD to prevent rapid decompression of the
airplane due to disbonding and subsequent cracking of the skin
panels.
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.
Restatement of Certain Requirements of AD 90-26-10
Inspections
(f) Prior to the accumulation of 12,000 flight cycles or within
the next 1,000 flight cycles after January 22, 1991 (the effective
date of AD 90-26-10), whichever occurs later, unless previously
accomplished within the last 1,000 flight cycles, conduct an
external detailed and external high frequency eddy current (HFEC)
inspection for cracks of the fuselage skin from body station (BS)
220 to BS 520, left and right hand side of the airplane between
stringers (S)-6 and S-14, excluding the skin lap joints, in
accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin 747-53A2321, dated October 31, 1989; or Revision 7,
dated October 27, 2005. After the effective date of this AD, only
Revision 7 may be used. Doing the inspections in this paragraph in
accordance with Revision 7 of the service bulletin eliminates the
need for doing the actions in paragraph (k) of this AD. Repeat the
inspections thereafter at intervals not to exceed 2,000 flight
cycles until the terminating modification in paragraph (g) of this
AD is done, except as provided by paragraph (h) of this AD.
Note 1: For the purposes of this AD, a detailed inspection is:
``An intensive examination of a specific item, installation, or
assembly to detect damage, failure, or irregularity. Available
lighting is normally supplemented with a direct source of good
lighting at an intensity deemed appropriate. Inspection aids such as
mirror, magnifying lenses, etc., may be necessary. Surface cleaning
and elaborate procedures may be required.''
Terminating Modification
(g) For airplanes line numbers 001 through 200, prior to the
accumulation of 20,000 total flight cycles, or within 48 months
after January 22, 1991, whichever occurs later: Perform the
terminating modification of the skin panel from BS 340 to BS 520, S-
6 to S-14, in accordance with the Accomplishment Instructions of
Boeing Alert Service Bulletin 747-53A2321, dated October 31, 1989;
or Revision 7, dated October 27, 2005. After the effective date of
this AD, only Revision 7 may be used. The modification consists of
replacing the skin panel with a new skin panel which was
manufactured utilizing the improved hot phosphoric anodize bonding
process.
(h) Replacement of the skin panel required by paragraph (g) of
this AD constitutes terminating action for the inspections from BS
340 to BS 520 required by paragraphs (f) and (k) of this AD. The
inspections from BS 220 to BS 340 required by paragraph (f) of this
AD are to be continued.
Adjustments for Cabin Differential Pressure
(i) Before the effective date of this AD: Flight cycles
conducted at 2.0 pounds per square inch (psi) or less cabin
differential pressure need not be counted for the purpose of this
airworthiness directive.
(j) Before the effective date of this AD: For Model 747SR
airplanes only, the threshold and repetitive inspection intervals
specified herein may be multiplied by the 1.2 adjustment factor
based on continued mixed operation at lower cabin pressure
differentials.
New Requirements of This AD
Inspections of Skins With Alodine-Coated Rivets
(k) For airplanes identified in Figure 9 of the Accomplishment
Instructions of Boeing Alert Service Bulletin 747-53A2321, Revision
7, dated October 27, 2005, as requiring additional inspection:
Within 150 flight cycles after the effective date of this AD, do the
inspection in paragraph (k)(1) or (k)(2) of this AD in accordance
with the Accomplishment Instructions of the service bulletin.
(1) Do an external detailed inspection for cracking of Area 1,
and repeat the inspection thereafter at intervals not to exceed 150
flight cycles until one of the actions in paragraph (k)(1)(i),
(k)(1)(ii), or (k)(1)(iii) is accomplished. Repeat the inspection of
Area 1 thereafter in accordance with the requirements of paragraph
(f) of this AD.
(i) The inspection in accordance with paragraph (k)(1) of this
AD has been done seven times at intervals not to exceed 150 flight
cycles. If this option is used: Within 150 flight cycles after the
seventh inspection, do the inspection required by paragraph (k)(2)
of this AD.
(ii) The inspection in accordance with paragraph (k)(2) has been
accomplished.
(iii) The inspections in accordance with paragraph (f) of this
AD has been accomplished once in accordance with Revision 7 of the
service bulletin.
(2) Do an external HFEC inspection for cracking of Area 1 in
accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin 747-53A2321, Revision 7, dated October 27, 2005.
Repeat the HFEC inspection of Area 1 thereafter in accordance with
the requirements of paragraph (f) of this AD.
[[Page 30078]]
Repair
(l) If any crack is found during any inspection required by this
AD: Before further flight, repair in accordance with the
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2321, dated October 31, 1989; or Revision 7, dated October 27,
2005. After the effective date of this AD, only Revision 7 of the
service bulletin may be used. Where Revision 7 of the service
bulletin specifies to contact Boeing for repair instructions: Before
further flight, repair using a method approved in accordance with
the procedures specified in paragraph (n) of this AD.
Adjustments to Compliance Time: Cabin Differential Pressure
(m) For the purposes of calculating the compliance threshold and
repetitive interval for actions required by paragraph (f), (g), and
(k) of this AD, on or after the effective date of this AD: All
flight cycles, including the number of flight cycles in which cabin
differential pressure is at 2.0 psi or less, must be counted when
determining the number of flight cycles that have occurred on the
airplane, and a 1.2 adjustment factor may not be used. However, for
airplanes on which the repetitive interval for the actions required
by paragraphs (f) and (k) of this AD have been calculated in
accordance with paragraph (i) or (j) of this AD by excluding the
number of flight cycles in which cabin differential pressure is at
2.0 pounds psi or less, or by using a 1.2 adjustment factor:
Continue to adjust the repetitive interval in accordance with
paragraph (i) or (j) of this AD until the next inspections required
by paragraph (f) or (k) of this AD are accomplished. Thereafter, no
adjustment to compliance times based on paragraph (i) or (j) of this
AD is allowed.
Alternative Methods of Compliance (AMOCs)
(n)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, has the authority to approve AMOCs for this AD, if requested in
accordance with the procedures found in 14 CFR 39.19.
(2) Before using any AMOC approved in accordance with Sec.
39.19 on any airplane to which the AMOC applies, notify the
appropriate principal inspector in the FAA Flight Standards
Certificate Holding District Office.
(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.
(4) AMOCs approved previously in accordance with AD 90-26-10 are
acceptable for compliance with the requirements of this AD, provided
that any alternative terminating action was not based upon
inspection results using sliding probe low-frequency eddy current
(LFEC), sliding probe HFEC, or mid-frequency eddy current (MFEC)
inspection method; and provided that any alternative method future
inspections did not incorporate sliding probe LFEC or MFEC
inspection method.
Issued in Renton, Washington, on May 16, 2006.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E6-8007 Filed 5-24-06; 8:45 am]
BILLING CODE 4910-13-P
