[Federal Register Volume 68, Number 117 (Wednesday, June 18, 2003)]
[Proposed Rules]
[Pages 36506-36509]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-15324]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NM-238-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200F, 747-200C, 747-300, 747SR, and 747SP
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to all Boeing Model 747-100, 747-
100B, 747-100B SUD, 747-200B, 747-200F, 747-200C, 747-300, 747SR, and
747SP series airplanes. This proposal would require repetitive
inspections for discrepancies of the structure near and common to the
upper chord and splice fittings of the rear spar of the wing, and
repair if necessary. This proposal also would provide for an optional
modification that, if accomplished, would terminate the repetitive
inspection requirement, but would necessitate eventual post-
modification inspections. This action is necessary to find and fix
fatigue cracking of structure near and common to the upper chord and
splice fittings of the rear spar of the wing, which could result in
loss of structural integrity of
[[Page 36507]]
the airplane. This action is intended to address the identified unsafe
condition.
DATES: Comments must be received by August 4, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2001-NM-238-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9 a.m. and 3 p.m., Monday through Friday, except
Federal holidays. Comments may be submitted via fax to (425) 227-1232.
Comments may also be sent via the Internet using the following address:
[email protected]. Comments sent via fax or the Internet must
contain ``Docket No. 2001-NM-238-AD'' in the subject line and need not
be submitted in triplicate. Comments sent via the Internet as attached
electronic files must be formatted in Microsoft Word 97 for Windows or
ASCII text.
The service information referenced in the proposed rule may be
obtained from Boeing Commercial Airplane Group, PO Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Tamara Anderson, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6421; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this action may be changed in
light of the comments received.
Submit comments using the following format:
[sbull] Organize comments issue-by-issue. For example, discuss a
request to change the compliance time and a request to change the
service bulletin reference as two separate issues.
[sbull] For each issue, state what specific change to the proposed
AD is being requested.
[sbull] Include justification (e.g., reasons or data) for each
request.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2001-NM-238-AD.'' The postcard will be date stamped
and returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules
Docket No. 2001-NM-238-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received reports indicating that fatigue cracking has
been found on the wing on several Boeing Model 747-100 and 747-200B
series airplanes. The cracking is adjacent and common to the upper
chord and splice fittings of the rear spar of the wing. Such cracking,
if not corrected, could result in loss of structural integrity of the
airplane.
The subject area on Model 747-100B, 747-100B SUD, 747-200F, 747-
200C, 747-300, 747SR, and 747SP series airplanes is similar to that on
the affected Model 747-100 and 747-200B series airplanes. Therefore,
all of these airplanes may be subject to the same unsafe condition.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
747-57A2314, Revision 1, dated January 9, 2003, which describes
procedures for repetitive inspections for discrepancies of the
structure near and common to the upper chord and splice fittings of the
rear spar of the wing, and repair if necessary. The inspection
procedures include removing existing bolts; performing an ultrasonic or
magnetic particle inspection for cracking of removed H-11 bolts;
performing a detailed inspection of all other removed bolts for
cracking, corrosion, or damage; replacing cracked, corroded, or damaged
bolts with new improved bolts; removing any installed repair bushings;
performing an open-hole high frequency eddy current (HFEC) inspection
for cracking of the bolt holes; installing new bushings if necessary;
reinstalling bolts that are not cracked, corroded, or damaged; torquing
the nuts; performing a detailed inspection of the shim between the kick
fitting and bulkhead strap for cracking or migration; and replacing the
shim with a new shim if necessary. Accomplishment of the actions
specified in the service bulletin is intended to adequately address the
identified unsafe condition.
The service bulletin also describes procedures for an optional
modification, which involves removing installed repair bushings,
performing an open-hole HFEC inspection for cracking of the bolt holes,
repairing any cracking that is found, oversizing bolt holes, and
installing new improved bolts. Accomplishment of the optional
modification eliminates the need for the repetitive inspections
described previously, but necessitates eventual post-modification
inspections. The post-modification inspections involve procedures
similar to those for the pre-modification inspections, which were
described previously.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require accomplishment of the actions specified in
the service bulletin described previously, except as discussed below
under the heading ``Differences Between Proposed Rule and Service
Bulletin.''
Clarification of Credit for Actions Accomplished Previously
Flag Note 1 of the logic diagram in Figure 1 of Boeing Alert
Service Bulletin 747-57A2314, Revision 1, specifies that, for certain
fastener holes on certain airplanes, an inspection per Figure 4, Step
14, of Boeing Service Bulletin 747-57-2110 is considered acceptable for
compliance with the initial inspection specified in paragraph (a) of
this proposed AD. We have reviewed and approved Boeing Service Bulletin
747-57-2110, Revision 6, dated November 21, 1991; and Revision 7, dated
April 23, 1998; and have determined that accomplishment of an initial
inspection before the effective date of this AD per Figure 4, Step 14,
of one of those revisions of the service bulletin would provide an
acceptable level of safety.
[[Page 36508]]
We have also reviewed Boeing Service Bulletin 747-57-2110, Revision 3,
dated February 19, 1987; Revision 4, dated May 26, 1988; and Revision
5, dated October 26, 1989. We have determined that accomplishment of an
initial inspection before the effective date of this AD per Figure 4,
Step 9, of one of those revisions of the service bulletin would provide
an acceptable level of safety. The first repeat inspection per
paragraph (b) of this proposed AD would be required to be accomplished
at the applicable interval established in paragraph (b) of this
proposed AD after the most recent inspection per Figure 4, Step 14, of
Boeing Service Bulletin 747-57-2110, Revision 6 or 7; or Figure 4, Step
9, of Boeing Service Bulletin 747-57-2110, Revision 3, 4, or 5.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, although the service bulletin specifies
that the manufacturer may be contacted for disposition of certain
repair conditions, this proposal would require the repair of those
conditions to be accomplished per a method approved by the FAA, or per
data meeting the type certification basis of the airplane approved by a
Boeing Company Designated Engineering Representative who has been
authorized by the FAA to make such findings.
Operators should also note that, although Appendix B of Boeing
Alert Service Bulletin 747-57A2314, Revision 1, describes procedures
for reporting discrepancies found during an inspection, this proposed
AD would not require those actions.
Cost Impact
There are approximately 593 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 176 airplanes of U.S. registry
would be affected by this proposed AD.
It would take approximately 8 work hours per airplane to accomplish
the proposed inspection, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the proposed inspection on
U.S. operators is estimated to be $84,480, or $480 per airplane, per
inspection cycle.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the proposed requirements of
this AD action, and that no operator would accomplish those actions in
the future if this proposed AD were not adopted. The cost impact
figures discussed in AD rulemaking actions represent only the time
necessary to perform the specific actions actually required by the AD.
These figures typically do not include incidental costs, such as the
time required to gain access and close up, planning time, or time
necessitated by other administrative actions.
Should an operator elect to accomplish the optional terminating
action that would be provided by this AD action, it would take
approximately 22 work hours to accomplish it, at an average labor rate
of $60 per work hour. The cost of required parts would be approximately
$10,700 per airplane. Based on these figures, the cost impact of the
optional terminating action would be approximately $12,020 per
airplane.
If the optional terminating action provided by this AD action is
accomplished, an eventual post-modification inspection would be
necessary. That inspection would take approximately 8 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the post modification
inspections would be approximately $480 per airplane, per inspection
cycle.
Regulatory Impact
The regulations proposed herein 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. Therefore, it
is determined that this proposal would not have federalism implications
under Executive Order 13132.
For the reasons discussed above, I certify that this proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the DOT
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);
and (3) if promulgated, 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. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new
airworthiness directive:
Boeing: Docket 2001-NM-238-AD.
Applicability: All Model 747-100, 747-100B, 747-100B SUD, 747-
200B, 747-200F, 747-200C, 747-300, 747SR, and 747SP series
airplanes; certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (k) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To find and fix fatigue cracking of structure near and common to
the upper chord and splice fittings of the rear spar of the wing,
which could result in loss of structural integrity of the airplane,
accomplish the following:
Initial Inspections
(a) Perform inspections for discrepancies of the structure near
and common to the upper chord and splice fittings of the rear spar
of the wing, per Part 2 of the Accomplishment Instructions of Boeing
Alert Service Bulletin 747-57A2314, Revision 1, dated January 9,
2003. The inspection procedures include removing existing bolts;
performing an ultrasonic or magnetic particle inspection for
cracking of removed H-11 bolts; performing a detailed inspection of
all other removed bolts for cracking, corrosion, or damage;
replacing cracked, corroded, or damaged bolts with new improved
bolts; removing any installed repair bushings; performing an open-
hole high frequency eddy current (HFEC) inspection for cracking of
the bolt holes; installing new bushings, if necessary; reinstalling
bolts that are not cracked, corroded, or damaged; torquing the nuts;
performing a detailed inspection of the shim between the kick
fitting and bulkhead strap for cracking or migration; and replacing
the shim with a new shim if necessary, except as provided by
paragraph (h) of this AD. Do the initial inspection at the time
specified in paragraph (a)(1) or (a)(2) of this AD, whichever is
later.
(1) Inspect at the earlier of the applicable times specified in
the ``Flights'' and ``Hours'' columns under the heading ``Initial
[[Page 36509]]
Inspection Threshold'' in Table 1 of Figure 1 of the service
bulletin. Where the ``Initial Inspection Threshold'' column of Table
1 of Figure 1 of the service bulletin specifies ``flights'' and
``hours,'' for the purposes of this paragraph the numbers in that
column are considered to be the airplane's total flight cycles and
total flight hours.
(2) Inspect within 18 months after the effective date of this
AD.
Note 2: For the purposes of this AD, a detailed inspection is
defined as: ``An intensive visual examination of a specific
structural area, system, installation, or assembly to detect damage,
failure, or irregularity. Available lighting is normally
supplemented with a direct source of good lighting at intensity
deemed appropriate by the inspector. Inspection aids such as mirror,
magnifying lenses, etc., may be used. Surface cleaning and elaborate
access procedures may be required.''
Repetitive Inspections
(b) Repeat the inspection required by paragraph (a) of this AD
at intervals not to exceed the earlier of the times specified in the
``Flights'' and ``Hours'' columns under the heading ``Repeat
Inspection Intervals'' in Table 1 of Figure 1 of Boeing Alert
Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003,
until paragraph (d) of this AD is accomplished. Where the ``Repeat
Inspection Intervals'' column of Table 1 of Figure 1 of the service
bulletin specifies ``flights'' and ``hours,'' for the purposes of
this paragraph, the figures in that column are considered to be the
number of flight cycles and flight hours from the time of the most
recent inspection per paragraph (a) or (b) of this AD, except as
provided by paragraph (g) of this AD.
Repair
(c) If any cracking is found during any inspection required by
paragraph (a) or (b) of this AD, before further flight, repair per
the Accomplishment Instructions of Boeing Alert Service Bulletin
747-57A2314, Revision 1, dated January 9, 2003, except as provided
by paragraph (h) of this AD.
Optional Modification
(d) Accomplishment of the modification specified in Part 4 of
the Accomplishment Instructions of Boeing Alert Service Bulletin
747-57A2314, Revision 1, dated January 9, 2003, constitutes
terminating action for the initial inspections required by paragraph
(a) of this AD and the repetitive inspections required by paragraph
(b) of this AD, provided that the repetitive post-modification
inspections required by paragraph (e) of this AD are initiated at
the applicable time. The modification procedures include removing
installed repair bushings, performing an open-hole HFEC inspection
for cracking of the bolt holes, repairing any cracking that is
found, oversizing bolt holes, and installing new improved bolts.
Post-Modification Inspections
(e) For airplanes on which the optional modification specified
in paragraph (d) of this AD is accomplished: At the earlier of the
times specified in the ``Flights'' and ``Hours'' columns under the
heading ``Post Modification Threshold'' in Table 2 of Figure 1 of
Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January
9, 2003, perform a post-modification inspection per Part 5 of the
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2314, Revision 1, dated January 9, 2003. The inspection
procedures include removing existing bolts; performing a detailed
inspection of removed bolts for cracking, corrosion, or damage;
replacing cracked, corroded, or damaged bolts with new bolts;
removing any installed repair bushings; performing an open-hole HFEC
inspection for cracking of the bolt holes; installing new bushings
if necessary; reinstalling bolts that are not cracked, corroded, or
damaged; torquing the nuts; performing a detailed inspection of the
shim between the kick fitting and bulkhead strap for cracking or
migration; and replacing the shim with a new shim if necessary;
except as provided by paragraph (h) of this AD. Where the ``Post
Modification Inspection Threshold'' column of Table 2 of Figure 1 of
the service bulletin specifies ``flights'' and ``hours,'' for the
purposes of this paragraph, the numbers in that column are
considered to be the flight cycles and flight hours after
accomplishment of the modification specified in paragraph (d) of
this AD.
(1) Repeat the inspection at intervals not to exceed the earlier
of the times specified in the ``Flights'' and ``Hours'' columns
under the heading ``Post Modification Repeat Inspection Intervals''
in Table 2 of Figure 1 of the service bulletin. Where the ``Post
Modification Repeat Inspection Intervals'' column of Table 2 of
Figure 1 of the service bulletin specifies ``flights'' and
``hours,'' for the purposes of this paragraph, the numbers in that
column are considered to be the flight cycles and flight hours since
the most recent inspection per paragraph (e) or (e)(1) of this AD.
(2) If any cracking is found during any inspection required by
paragraph (e) or (e)(1) of this AD, before further flight, repair
per the Accomplishment Instructions of Boeing Alert Service Bulletin
747-57A2314, Revision 1, dated January 9, 2003, except as provided
by paragraph (h) of this AD.
Actions Accomplished Per Previous Issue of Service Bulletin
(f) Inspections, repairs, or modifications accomplished before
the effective date of this AD per Boeing Alert Service Bulletin 747-
57A2314, including Appendix A and B, dated June 28, 2001, are
considered acceptable for compliance with the corresponding action
specified in this AD, except as provided by paragraph (h) of this
AD.
(g) As specified in Flag Note 1 of the logic diagram in Figure 1
of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated
January 9, 2003: An inspection accomplished before the effective
date of this AD per Figure 4, Step 14, of Boeing Service Bulletin
747-57-2110, Revision 6, dated November 21, 1991; or Revision 7,
dated April 23, 1998; is considered acceptable, as applicable, for
compliance with the initial inspection required by paragraph (a) of
this AD. An inspection accomplished before the effective date of
this AD per Figure 4, Step 9, of Boeing Service Bulletin 747-57-
2110, Revision 3, dated February 19, 1987; Revision 4, dated May 26,
1988; and Revision 5, dated October 26, 1989; is also considered
acceptable, as applicable, for compliance with the initial
inspection required by paragraph (a) of this AD. The first repeat
inspection per paragraph (b) of this AD must be accomplished at the
applicable interval established in paragraph (b) of this AD after
the most recent inspection per Figure 4, Step 14, of Boeing Service
Bulletin 747-57-2110, Revision 6 or 7; or Figure 4, Step 9, of
Boeing Service Bulletin 747-57-2110, Revision 3, 4, or 5.
Exception to Instructions in Service Bulletin
(h) Where Boeing Alert Service Bulletin 747-57A2314, Revision 1,
dated January 9, 2003, specifies to contact Boeing for appropriate
action, before further flight, repair per a method approved by the
Manager, Seattle ACO, or per data meeting the type certification
basis of the airplane approved by a Boeing Company DER who has been
authorized by the Manager, Seattle ACO, to make such findings. For a
repair method to be approved, the approval must specifically
reference this AD.
(i) Although Appendix B of Boeing Alert Service Bulletin 747-
57A2314, Revision 1, dated January 9, 2003, refers to a reporting
requirement, such reporting is not required by this AD.
Parts Installation
(j) Except as provided by paragraphs (a) and (b) of this AD, as
of the effective date of this AD, no person may install any alloy
steel bolt in any location specified in this AD on any airplane
listed in the applicability of this AD.
Alternative Methods of Compliance
(k) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Seattle ACO. Operators shall submit
their requests through an appropriate FAA Principal Maintenance
Inspector, who may add comments and then send it to the Manager,
Seattle ACO.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Special Flight Permits
(l) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Issued in Renton, Washington, on June 11, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 03-15324 Filed 6-17-03; 8:45 am]
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