[Federal Register: May 17, 2006 (Volume 71, Number 95)]
[Rules and Regulations]
[Page 28570-28574]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17my06-7]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-22510; Directorate Identifier 2004-NM-32-AD;
Amendment 39-14600; AD 2006-10-16]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
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SUMMARY: The FAA is superseding two existing airworthiness directives
(ADs); one AD is applicable to all Boeing Model 747 airplanes and the
other AD is applicable to certain Boeing Model 747 airplanes. The first
AD currently requires repetitive inspections for cracking of the upper
skin of the horizontal stabilizer center section and the rear spar
upper chord, and repair if necessary. The other AD currently requires
repetitive inspections for cracking of the upper skin of the outboard
and center sections of the horizontal stabilizer and the rear spar
structure, hinge fittings, terminal fittings, and splice plates; and
repair if necessary. This new AD adds, for certain airplanes,
repetitive inspections for cracking of the outboard and center sections
of the horizontal stabilizer and repair if necessary. For certain other
airplanes, this new AD adds a detailed inspection to determine the type
of fasteners, related investigative actions, and repair if necessary.
This new AD also revises the compliance times for certain inspections
and adds alternative inspections for cracking of the upper skin of the
center section and rear spar upper chord. This AD results from reports
of cracking in the outboard and center section of the aft upper skin of
the horizontal stabilizer, the rear spar chord, rear spar web, terminal
fittings, and splice plates; and a report of fractured and cracked
steel fasteners. We are issuing this AD to detect and correct this
cracking, which could lead to reduced structural capability of the
outboard and center sections of the horizontal stabilizer and could
result in loss of control of the airplane.
DATES: This AD becomes effective June 21, 2006.
On July 15, 2003 (68 FR 38583, June 30, 2003), the Director of the
Federal Register approved the incorporation by reference of Boeing
Alert Service Bulletin 747-55A2050, Revision 1, dated May 1, 2003.
On April 3, 2002 (67 FR 12464, March 19, 2002), the Director of the
Federal Register approved the incorporation by reference of Boeing
Alert Service Bulletin 747-55A2050, dated February 28, 2002.
ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov
or in person at the Docket Management Facility, U.S.
Department of Transportation, 400 Seventh Street, SW., Nassif Building,
Room PL-401, Washington, DC.
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207, for service information identified in this 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:
Examining the Docket
You may examine the airworthiness directive (AD) docket on the
Internet at http://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 street address stated in the ADDRESSES section.
Discussion
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR
[[Page 28571]]
part 39 to include an AD that supersedes AD 2002-06-02, amendment 39-
12678 (67 FR 12464, March 19, 2002), and AD 2003-13-09, amendment 39-
13209 (68 FR 38583, June 30, 2003). AD 2002-06-02 applies to all Boeing
Model 747 airplanes; AD 2003-13-09 applies to certain Boeing Model 747
airplanes. That NPRM was published in the Federal Register on September
26, 2005 (70 FR 56145). That NPRM proposed to supersede AD 2002-06-02
to continue to require repetitive inspections for cracking of the upper
skin of the horizontal stabilizer center section and the rear spar
upper chord, and repair, if necessary. That NPRM also proposed to
supersede AD 2003-13-09 to continue to require repetitive inspections
for cracking of the upper skin of the outboard and center sections of
the horizontal stabilizer and the rear spar structure, hinge fittings,
terminal fittings, and splice plates; and repair if necessary. That
NPRM also proposed, for certain airplanes, to add repetitive
inspections for cracking of the horizontal stabilizer center and
outboard section, and repair if necessary. For certain other airplanes,
that NPRM proposed to add a detailed inspection to determine if
fasteners are Maraging or H-11 steel fasteners, related investigative
actions, and corrective action if necessary. That NPRM also proposed to
revise the compliance times for certain inspections and add alternate
high frequency eddy current (HFEC) inspections for cracking of the
upper skin of the center section and rear spar upper chord.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments that have been
received on the NPRM.
Request To Clarify Instructions in Paragraph (g)
Boeing asks that paragraph (g) of the NPRM be clarified to direct
operators to the applicable section of the Work Instructions in Boeing
Alert Service Bulletin 747-55A2050, Revision 1, dated May 1, 2003
(referenced in the NPRM as the appropriate source of service
information for accomplishing the required actions). We agree with
Boeing and have clarified paragraphs (g), (g)(1), and (g)(2) of this AD
accordingly.
Request To Change Paragraphs (f)(1) and (f)(2)
Boeing also asks that we change paragraphs (f)(1) and (f)(2) of the
NPRM to require accomplishing the inspections in accordance with Part 1
of the Work Instructions of Revision 1 of the alert service bulletin,
instead of specifying paragraph (f) of the NPRM. Boeing states that
this change will make the inspection methods consistent with the
inspection intervals in paragraph (f) and Revision 1 of the alert
service bulletin.
We acknowledge Boeing's concern, and we agree that the inspection
must be accomplished in accordance with Part 1 of the Work
Instructions; however, paragraph (f) of this AD already requires that
the inspections be accomplished as of the effective date of this AD in
accordance with Part 1 of the Work Instructions of Boeing Alert Service
Bulletin 747-55A2050, Revision 1, dated May 1, 2003. Since paragraphs
(f)(1) and (f)(2) of this AD require that the repetitive inspections be
accomplished per paragraph (f); we have made no change to the AD in
this regard.
Request To Change Paragraph (i)
Boeing also asks that we change paragraph (i) of the NPRM to
require accomplishing the inspections in accordance with Part 4 of the
Work Instructions of Revision 1 of the alert service bulletin. Boeing
states that this change will direct operators to the correct paragraph
in the service bulletin.
We acknowledge Boeing's concern and we agree that the inspection
must be accomplished in accordance with Part 4 of the Work Instructions
of Revision 1 of the alert service bulletin. However, paragraph (i) of
this AD requires that the inspections be accomplished per paragraph
(g)(2) of this AD, which identifies accomplishing the inspections per
Part 4 of the Work Instructions of Revision 1 of the alert service
bulletin. Therefore, it is not necessary to restate those requirements
in paragraph (i). We have made no change to the AD in this regard.
Request To Change Paragraph (k)
In addition, Boeing asks that we change paragraph (k) of the NPRM
to add the following: ``If any bolt is cracked or fractured, high
frequency eddy current (HFEC) inspect the bolt hole and replace the
bolt, in accordance with Part 5 of the Work Instructions of Revision 1
of the alert service bulletin.'' Boeing states that the NPRM contains
no instructions for replacing cracked or broken bolts, and
reinstallation of those bolts could result in overloaded adjacent
bolts.
We do not agree with Boeing that a change is necessary. Paragraph
(k) of this AD provides instructions for repetitive inspections for
magnetic fasteners that are not cracked or fractured. It would not be
appropriate to combine the requirements for bolts that are not cracked
or fractured, as specified in paragraph (k), with those for cracked or
fractured bolts. Paragraph (j) of this AD provides instructions for
inspecting for any cracked or fractured magnetic fastener. Paragraph
(j) specifies that ``corrective action'' must be accomplished by doing
all the actions specified in Part 5 of the Work Instructions of
Revision 1 of the alert service bulletin. Part 5, Step 1.l., describes
procedures for open hole HFEC inspections of the bolt hole, and
replacement of the bolt. Therefore, we have made no change to the AD in
this regard.
Request To Change Paragraph (n)
Boeing also asks that we change paragraph (n) of the NPRM to allow
a grace period for replacing H-11 (magnetic) or Maraging steel bolts.
Boeing states that operators accomplishing magnetic and fluorescent
particle inspections of H-11 or Maraging steel bolts would be
prohibited from re-installing undamaged H-11 or Maraging steel bolts.
Boeing adds that paragraph (n) of the NPRM conflicts with paragraph (k)
of the NPRM, which allows repeat inspections of H-11 or Maraging steel
bolts. Boeing notes that operators accomplishing magnetic and
fluorescent particle inspections of H-11 or Maraging steel bolts, or
open hole HFEC inspections of Zone B, would be unable to re-install
undamaged H-11 or Maraging steel bolts. Operators would be required to
install Inconel bolts within 12 months after the effective date of the
AD (for Zone B inspections), or within 18 months after the effective
date of the AD (for Zone C inspections). H-11 or Maraging steel bolts
were originally installed on 460 airplanes that are currently
operating, and Boeing is unable to supply 460 bolt kits within a 12 to
18 month period. Boeing adds that there are currently no bolt kits in
stock, and only 3 bolt kits scheduled for delivery; therefore, the
requirements in paragraph (n) could ground up to 460 airplanes. In
addition, operators accomplishing ultrasonic inspections of H-11 or
Maraging steel bolts per the Boeing 747 Nondestructive Test Manual D6-
7171, Part 4, Chapter 51-00-00, will require bolt standards with
identical diameter and grip lengths as the bolts installed on the
airplane. These bolt standards are not readily available.
We acknowledge Boeing's concern, and we agree that there would be a
hardship on operators if we required replacement of bolts when they
were
[[Page 28572]]
unable to obtain spare parts. However, we have determined that a
shortage of parts is not a concern since this AD does not require
removal of H-11 bolts for inspection. The only bolts that this AD
requires replacing are those that are found cracked or that an operator
elects to replace. Although paragraph (n) of this AD does not allow re-
installation of a non-cracked H-11 or Maraging steel bolt, that
paragraph does not require removal of the bolt in the first place.
Instead, paragraphs (j) and (k) of this AD require inspections of the
magnetic bolts in accordance with Part 5 of the Work Instructions of
Revision 1 of the alert service bulletin. Step 1.j. of Part 5 provides
the option of removing the bolt or leaving the bolt in place and
accomplishing an ultrasonic inspection. Therefore, there is no hardship
for operators since they may choose to leave the bolt in place and
accomplish an ultrasonic inspection. If no cracking is found, operators
are allowed to repeat that inspection with the bolt in place as long as
no cracking is found during any inspection. Therefore, we have made no
change to the AD in this regard.
Request To Change Compliance Time in Paragraph (f)(1)
Boeing also asks that we change paragraph (f)(1) of the NPRM to add
a 5,600-flight-hour cap to the compliance time for the initial
inspection done after the effective date of the AD. Boeing states that
this change will make the inspection methods consistent with the
inspection intervals in paragraph (f) and with Revision 1 of the alert
service bulletin.
We do not agree with Boeing. We did not add a 5,600-flight-hour cap
to the compliance time for the initial inspection so that operators
would be allowed to transition to the new interval if they were already
accomplishing the repetitive inspections required by AD 2002-06-02.
Certain requirements of that AD have been retained in this AD. After
the initial inspection, operators will be limited to repeating the
inspection within 1,000 flight cycles or 5,600 flight hours, whichever
is first, which coincides with Revision 1 of the alert service
bulletin. We have made no change to the AD in this regard.
Request To Extend Compliance Time in Paragraph (h)
Northwest Airlines (NWA) asks that we extend the compliance time
for the initial inspection, as specified in paragraphs (h)(2)(i)(B) and
(h)(2)(ii)(B) of the NPRM, from 12 to 18 months. NWA states that the
most significant impact in the NPRM is the requirement to perform the
paragraph (g) inspections within the initial inspection threshold
specified in paragraphs (h)(2)(i)(B) and (h)(2)(ii)(B). NWA notes that
the proposed thresholds differ significantly from those in AD 2003-13-
09 (referenced in paragraph (h)(1)(ii) of the NPRM). NWA adds that 6 of
its Model 747-200 airplanes may require inspections within 12 months
from the effective date of a new adopted rule. NWA states that
extending the compliance time to 18 months will allow accomplishment of
the inspections during planned heavy maintenance C-check visits.
We do not agree with NWA. The 12-month compliance time in
paragraphs (h)(2)(i)(B) and (h)(2)(ii)(B) is in the referenced service
bulletin, but was not included in AD 2003-13-09 because it did not meet
the criteria necessary to be included in an immediately adopted rule.
AD 2003-13-09 included interim action which specified that we were
considering a separate rulemaking action to address these inspections
at a later date. We have determined that the compliance time, as
proposed, represents the maximum interval of time allowable for the
affected airplanes to continue to safely operate before the inspections
are done. Since maintenance schedules vary among operators, there would
be no assurance that the airplane would be inspected during that
maximum interval of 18 months. In addition, the 12-month compliance
time agrees with the manufacturer's service bulletin referenced in the
AD. We have made no change to the AD in this regard.
Conclusion
We have carefully reviewed the available data, including the
comments that have been received, and determined that air safety and
the public interest require adopting the AD with the changes described
previously. These changes will neither increase the economic burden on
any operator nor increase the scope of the AD.
Costs of Compliance
This AD affects about 1,087 Model 747 airplanes worldwide and
affects about 227 airplanes of U.S. registry. The following table
provides the estimated costs for U.S. operators to comply with this AD.
The costs for the inspections are per inspection cycle.
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Average
Action Work labor rate Cost per Fleet cost
hours per hour airplane
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Zone A Detailed Inspection (required by AD 8 $65 $520 $118,040.
2002-06-02).
Zone A NDT Inspection, if done................ 10 65 650 Unknown.
Zone B NDT Inspection (required by AD 2003-13- 8 65 520 Unknown.
09 for Groups 1, 2, and 3 airplanes).
Zone B Open-hole NDT Inspection (new proposed 30 65 1,950 Unknown.
action for Groups 3, 4, and 5 airplanes; and
for Groups 1, 2, and 3 airplanes, if done).
Zone C Maraging or H-11 Steel Fastener 8 65 520 Unknown.
Inspection (new proposed action for Groups
1,2, and 3 airplanes).
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Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, Section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
[[Page 28573]]
Regulatory Findings
We have determined that this AD will not have federalism
implications under Executive Order 13132. This AD will not have a
substantial direct effect on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866;
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and
(3) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to
comply with this AD and placed it in the AD docket. See the ADDRESSES
section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, under the authority delegated to me by the Administrator,
the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
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]
0
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by
removing amendment 39-12678 (67 FR 12464, March 19, 2002), and
amendment 39-13209 (68 FR 38583, June 30, 2003), and by adding the
following new airworthiness directive (AD):
2006-10-16 Boeing: Amendment 39-14600. Docket No. FAA-2005-22510;
Directorate Identifier 2004-NM-32-AD.
Effective Date
(a) This AD becomes effective June 21, 2006.
Affected ADs
(b) This AD supersedes AD 2002-06-02 and AD 2003-13-09.
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 was prompted by reports of cracking in the outboard
and center section of the aft upper skin of the horizontal
stabilizer, the rear spar chord, rear spar web, terminal fittings,
and splice plates; and a report of fractured and cracked steel
fasteners. We are issuing this AD to detect and correct this
cracking, which could lead to reduced structural capability of the
outboard and center sections of the horizontal stabilizer and could
result in loss of control of the airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Certain Requirements of AD 2002-06-02: To Be Done in Accordance With
New Revision of the Service Bulletin
Repetitive Inspections for Zone A
(f) Before the accumulation of 24,000 total flight cycles, or
within 90 days after April 3, 2002 (the effective date of AD 2002-
06-02), whichever occurs later: Except as provided by paragraph (l)
of this AD, ``Optional High Frequency Eddy Current (HFEC)
Inspections for Zone A,'' do a detailed inspection for cracking of
the upper skin of the horizontal stabilizer center section and the
rear spar upper chord, in accordance with the Work Instructions and
Figure 1 of Boeing Alert Service Bulletin 747-55A2050, dated
February 28, 2002; or in accordance with Part 1 of the Work
Instructions of Boeing Alert Service Bulletin 747-55A2050, Revision
1, dated May 1, 2003. (The inspection procedures include a detailed
inspection for cracking of the upper horizontal skin and of the
vertical and horizontal flanges of the rear spar upper chord.) As of
the effective date of this AD, do the detailed inspection in
accordance with Part 1 of the Work Instructions of Boeing Alert
Service Bulletin 747-55A2050, Revision 1, dated May 1, 2003. Repeat
the detailed inspection thereafter at the times specified in
paragraphs (f)(1) and (f)(2) of this AD, as applicable.
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 mirrors,
magnifying lenses, etc., may be necessary. Surface cleaning and
elaborate procedures may be required.''
(1) For airplanes on which the detailed inspection required by
paragraph (a) of AD 2002-06-02 has been done before the effective
date of this AD: Within 1,000 flight cycles after the last detailed
inspection, do the detailed inspection specified in paragraph (f) of
this AD and repeat the detailed inspection specified in paragraph
(f) of this AD thereafter at intervals not to exceed 1,000 flight
cycles or 5,600 flight hours, whichever comes first.
(2) For airplanes on which the detailed inspection required by
paragraph (a) of AD 2002-06-02 has not been done before the
effective date of this AD: After accomplishing the initial
inspection, repeat the detailed inspection specified in paragraph
(f) of this AD thereafter at intervals not to exceed 1,000 flight
cycles or 5,600 flight hours, whichever comes first.
Requirements of AD 2003-13-09, With New Compliance Times Required by
This AD
Repetitive Inspections for Zone B: Groups 1 Through 3
(g) For Groups 1, 2, and 3 airplanes identified in paragraph
1.A. Effectivity of Boeing Alert Service Bulletin 747-55A2050,
Revision 1, dated May 1, 2003: At the time specified in paragraph
(h) of this AD, do the Zone B inspections, as required by either
paragraph (g)(1) or (g)(2) of this AD, in accordance with Part 3 of
the Work Instructions of Boeing Alert Service Bulletin 747-55A2050,
Revision 1, dated May 1, 2003, except as provided by paragraph (n)
of this AD. Repeat the applicable inspection at the applicable time
specified in Sheet 2 of Figure 1 of the service bulletin.
(1) Do nondestructive test (NDT) inspections for cracking of the
upper skin of the outboard and center sections of the horizontal
stabilizer and the rear spar structure, hinge fittings, terminal
fittings, and splice plates, in accordance with Part 3 of the Work
Instructions of the service bulletin. The inspections include an
ultrasonic inspection of the outboard and center sections, rear spar
upper chords under the hinge fitting halves, upper skins under the
splice plates, and the rear spar webs behind the terminal fittings;
a HFEC inspection of the terminal fitting around the fasteners; a
low frequency eddy current inspection of the splice plates around
the fasteners; a surface HFEC inspection of the rear spar upper
chords in the radius area above the terminal fitting and the lower
surface of the horizontal flange; and an HFEC inspection of the rear
spar webs in the exposed area above the terminal fitting.
(2) In lieu of the inspections specified in paragraph (g)(1) of
this AD: Do an alternate open hole HFEC inspection for cracking of
the splice plates, terminal fittings, hinge fitting halves, rear
spar upper chords, rear spar webs, and upper skins; and replace H-11
bolts with Inconel bolts; in accordance with Part 4 of the Work
Instructions of the service bulletin, except as provided by
paragraph (n) of this AD.
(h) For Groups 1, 2, and 3 airplanes identified in paragraph
1.A. Effectivity of Boeing Alert Service Bulletin 747-55A2050,
Revision 1, dated May 1, 2003: Do the inspections required by
paragraph (g) of this AD at the earlier of the times specified in
paragraphs (h)(1) and (h)(2) of this AD.
(1) At the later of the times specified in paragraphs (h)(1)(i)
and (h)(1)(ii) of this AD.
(i) Before the accumulation of 27,000 total flight cycles or
117,000 total flight hours, whichever is first.
(ii) Within 90 days after July 15, 2003 (the effective date of
AD 2003-13-09).
[[Page 28574]]
(2) At the applicable times specified in paragraphs (h)(2)(i)
and (h)(2)(ii) of this AD.
(i) For Groups 1 and 3 airplanes identified in paragraph 1.A.
Effectivity of Boeing Alert Service Bulletin 747-55A2050, Revision
1, dated May 1, 2003: At the latest of the times specified in
paragraphs (h)(2)(i)(A) and (h)(2)(i)(B) of this AD.
(A) Before the accumulation of 20,000 total flight cycles or
85,000 total flight hours, whichever is first.
(B) Within 12 months after the effective date of this AD.
(ii) For Group 2 airplanes identified in paragraph 1.A.
Effectivity of Boeing Alert Service Bulletin 747-55A2050, Revision
1, dated May 1, 2003: At the latest of the times specified in
paragraphs (h)(2)(ii)(A) and (h)(2)(ii)(B) of this AD.
(A) Before the accumulation of 22,000 total flight cycles or
95,000 total flight hours, whichever is first.
(B) Within 12 months after the effective date of this AD.
Additional Requirements of This AD
Repetitive Inspections for Zone B: Groups 4 Through 6
(i) For Groups 4, 5, and 6 airplanes identified in paragraph
1.A. Effectivity of Boeing Alert Service Bulletin 747-55A2050,
Revision 1, dated May 1, 2003: At the later of the times specified
in paragraphs (i)(1) and (i)(2) of this AD, do the Zone B
inspections as specified in paragraph (g)(2) of this AD. Repeat the
applicable inspection at the applicable time specified in Sheet 3 of
Figure 1 of the service bulletin.
(1) Before the accumulation of 20,000 total flight cycles or
85,000 total flight hours, whichever is first.
(2) Within 12 months after the effective date of this AD.
Repetitive Inspections for Zone C: Groups 1 Through 3
(j) For Groups 1, 2, and 3 airplanes identified in paragraph
1.A. Effectivity of Boeing Alert Service Bulletin 747-55A2050,
Revision 1, dated May 1, 2003: Within 18 months after the effective
date of this AD, do a detailed inspection to determine if fasteners
common to the horizontal stabilizer outboard and center section
upper chords at the hinge fitting halves and the splice plates are
magnetic, related investigative actions (includes ultrasonic,
magnetic particle, or fluorescent particle inspections for any
cracked or fractured Maraging or H-11 steel fastener), and
corrective actions by accomplishing all the actions specified in
Part 5 of the Work Instructions of the service bulletin, except as
provided by paragraph (n) of this AD.
(k) If, during the actions required by paragraph (j) of this AD,
any fastener is found to be magnetic and is not cracked or
fractured, repeat the related investigative actions and corrective
actions specified in paragraph (j) of this AD at the time specified
in Sheet 4 of Figure 1 of Boeing Alert Service Bulletin 747-55A2050,
Revision 1, dated May 1, 2003.
Optional High Frequency Eddy Current (HFEC) Inspections for Zone A
(l) In lieu of the detailed inspection specified in paragraph
(f) of this AD: Do an HFEC inspection for cracking of the upper skin
of the horizontal stabilizer center section and the rear spar upper
chord, in accordance with Part 2 of the Work Instructions of Boeing
Alert Service Bulletin 747-55A2050, Revision 1, dated May 1, 2003.
Repeat the HFEC inspection thereafter at intervals not to exceed
2,700 flight cycles or 15,000 flight hours, whichever comes first.
Repair
(m) If any discrepancy (cracking or damage) is found during any
inspection or related investigative action required by paragraphs
(f), (g), (i), or (l) of this AD: Before further flight, repair in
accordance with the Work Instructions of Boeing Alert Service
Bulletin 747-55A2050, Revision 1, dated May 1, 2003, except as
provided by paragraph (n) of this AD. Where the service bulletin
specifies to contact the manufacturer for appropriate action: Before
further flight, repair according to a method approved by the
Manager, Seattle Aircraft Certification Office (ACO), FAA; or
according to data meeting the certification basis of the airplane
approved by an Authorized Representative for the Boeing 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, and the approval must specifically refer to this AD.
Parts Installation
(n) As of the effective date of this AD, no person may install
any Maraging or H-11 steel fasteners in the locations specified in
this AD. Where Boeing Alert Service Bulletin 747-55A2050, Revision
1, dated May 1, 2003, specifies to install H-11 bolts (kept
fasteners), this AD requires installation of Inconel bolts.
Alternative Methods of Compliance (AMOCs)
(o)(1) The Manager, Seattle ACO, FAA, has the authority to
approve AMOCs for this AD, if requested using 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) AMOCs, approved previously per AD 2002-06-02 or AD 2003-13-
09, are approved as AMOCs for the corresponding provisions of this
AD, for the repaired area only.
Material Incorporated by Reference
(p) You must use Boeing Alert Service Bulletin 747-55A2050,
dated February 28, 2002; or Boeing Alert Service Bulletin 747-
55A2050, Revision 1, dated May 1, 2003; as applicable; to perform
the actions that are required by this AD, unless the AD specifies
otherwise.
(1) On July 15, 2003 (68 FR 38583, June 30, 2003), the Director
of the Federal Register approved the incorporation by reference of
Boeing Alert Service Bulletin 747-55A2050, Revision 1, dated May 1,
2003.
(2) On April 3, 2002 (67 FR 12464, March 19, 2002), the Director
of the Federal Register approved the incorporation by reference of
Boeing Alert Service Bulletin 747-55A2050, dated February 28, 2002.
(3) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207, for a copy of this service information. You
may review copies at the Docket Management Facility, U.S. Department
of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif
Building, Washington, DC; on the Internet at http://dms.dot.gov; or
at the National Archives and Records Administration (NARA). For
information on the availability of this material at the NARA, call
(202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html
.
Issued in Renton, Washington, on May 8, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 06-4541 Filed 5-16-06; 8:45 am]
BILLING CODE 4910-13-P