[Federal Register: August 8, 2003 (Volume 68, Number 153)]
[Rules and Regulations]
[Page 47218-47221]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08au03-10]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NM-117-AD; Amendment 39-13261; AD 2003-16-08]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100, -100B, -100B SUD,
-200B, -200C, -200F, -300, -400, -400D, and -400F Series Airplanes; and
Model 747SR Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Boeing Model 747-100, -100B, -100B SUD, -200B, -
200C, -200F, -300, -400, -400D, and -400F series airplanes; and Model
747SR series airplanes. For certain airplanes, this AD requires
repetitive inspections of the clevis bushings on the inboard and
outboard sequence carriages of the wing foreflap for bushing migration,
and corrective action if necessary; replacement of existing bushings
with new bushings, which terminates the repetitive inspections; and
replacement of the bushing markers with new markers, if necessary, to
indicate the correct bushing orientation. For certain other airplanes,
this AD requires a one-time inspection to determine whether the
bushings are in the correct orientation, and follow-on actions. The
actions specified by this AD are intended to prevent the loss of an
inboard trailing edge foreflap during flight, and subsequent damage to
the airplane in flight. This action is intended to address the
identified unsafe condition.
DATES: Effective September 12, 2003.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 12, 2003.
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the Federal
Aviation Administration (FAA), Transport Airplane Directorate, Rules
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of
the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Gary Oltman, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6443; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Boeing Model 747-100, -
100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, and -400F
series airplanes; and Model 747SR series airplanes; was published in
the Federal Register on January 4, 2002 (67 FR 544). For certain
airplanes, that action proposed to require repetitive inspections of
the clevis bushings on the inboard and outboard sequence carriages of
the wing foreflap for bushing migration, and corrective action if
necessary; replacement of existing bushings with new bushings, which
would terminate the repetitive inspections; and replacement of the
bushing markers with new markers, if necessary, to indicate the correct
bushing orientation. For certain other airplanes, that action proposed
to require a one-time inspection to determine whether the bushings are
in the correct orientation, and follow-on actions.
Explanation of Relevant Service Information
The proposed AD cited Boeing Service Bulletin 747-57-2166, Revision
5, dated May 13, 1993, as the appropriate source of service information
for accomplishment of the proposed requirements. Since the proposed AD
was issued, Boeing has further revised the service bulletin; however,
Revision 6, dated January 16, 2003, adds no new requirements.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Request To Withdraw Proposed AD
One operator disagrees that the proposed AD is necessary or
justified. The operator questions the need for additional rulemaking in
light of existing regulatory actions that address a similar incident
and unsafe condition. The operator notes that inspection of the
bushings that are the subject of the proposed AD is also required by AD
92-27-04, amendment 39-8437 (57 FR 59801, December 16, 1992), as
corrected (58 FR 8693, February 17, 1993). In addition, the operator
considers the incident described in the proposed AD (involving a
foreflap separating from and colliding with an airplane in flight) to
be the same situation addressed by AD 99-05-02, amendment 39-11051 (64
FR 9906, March 1, 1999). The operator further suggests that the
proposed requirement to permanently install markers would subject the
markers to considerable wear and, in combination with other related
ADs, could have long-term and costly effects on operations and
maintenance. Moreover, the operator doubts that incorrect markers would
still be installed on airplanes after 8 years in service, asserting
that the manufacturer has purged all stocks of incorrect markers.
The FAA does not concur with the request to withdraw the proposed
AD. In the incident that led to this rulemaking, the foreflap departed
the airplane during flight and collided with the fuselage, resulting in
a 5\1/2\-foot by 3-foot hole in the fuselage--despite the prior
accomplishment of the requirements of AD 92-27-04 on that airplane.
This incident illustrates the danger of large pieces of airplane
structure departing the airplane. AD 99-05-02 was issued to correct
certain conditions with certain shims and
[[Page 47219]]
fasteners associated with flap carriages and is not related to the
bushing problem addressed by this AD.
Also, the commenter did not provide adequate data to support the
claim that no incorrect markers would still be installed on an airplane
after 8 years in service. Contrary to the commenter's assertion, Boeing
reports that its supply of incorrect markers has not been purged. When
Boeing first revised the marker to show the correct orientation, the
part number of the new marker was the same as the marker showing the
incorrect orientation (part number BAC27EWG-24). Boeing created a new
marker with a new part number (BAC27EWG-39). According to Boeing
Service Letter 747-SL-57-77, ``* * * due to the large numbers of
correct BAC27EWG-24 markers already in stock, the BAC27EWG-39 was made
an option to the correct BAC27EWG-24 marker. This may have allowed some
of the incorrect BAC27EWG-24 markers to be installed.'' Therefore,
because some markers showing incorrect orientation may still be
installed on affected airplanes, the FAA finds it necessary to issue
this AD.
Request To Reconcile Applicability
One commenter identifies a difference between the applicability of
the proposed AD and the effectivity of Service Bulletin 747-57-2166.
The proposed AD includes Model 747-400s, which are not listed in the
service bulletin. The commenter requests that this disagreement be
corrected before the AD is issued.
The FAA acknowledges the disagreement; however, as explained in the
proposed AD, Boeing had reported (via Service Letter 747-SL-57-77,
dated November 18, 1993) that the subject incorrect markers may also be
installed on Model 747-400 airplanes. Model 747-400 airplanes (except
the Model 747SP, which has flaps of a different design) are correctly
included in the applicability of this AD. No change to the final rule
is necessary regarding this issue.
Request To Revise Identity of Airplanes Affected by Certain
Requirements
One operator requests that paragraphs (a) and (b) of the proposed
AD be revised to clarify the group of airplanes subject to those
proposed requirements. Paragraphs (a) and (b), as proposed, identify
airplanes with respect to bushing replacement done in accordance with a
certain service bulletin. However, for certain airplanes (i.e., those
with line numbers after 316), the bushings were installed correctly by
means of a production change. The operator concludes that paragraphs
(a) and (b), as written in the proposed AD, would have excluded
airplanes on which the production change had been completed.
The FAA concurs with the request, for the reasons provided by the
commenter. The intent of paragraphs (a) and (b)--as well as (c) and
(d)--of this AD is to consider the status of the bushing installation--
regardless of the method followed (i.e., the service bulletin or the
production change). Paragraphs (a) through (d) have been revised in the
final rule to reflect this intent.
Request To Revise Compliance Time
One operator requests that the proposed grace period and repetitive
inspection interval be revised to correspond to the operator's C-check
schedule. The proposed 1,200-flight-cycle interval would not conform to
the operator's C-check schedule, so the operator would need to schedule
intermediate maintenance to comply with the proposed AD. This commenter
suggests that the proposed grace period and repetitive inspection
interval be changed to ``1,200 flight cycles or 18 months, whichever
occurs later,'' which would allow the inspections to be accomplished
during the operator's regularly scheduled maintenance.
The FAA does not concur. Failure of the clevis lug is flight-cycle-
dependent, not time-dependent. Allowing an 18-month interval between
inspections for high utilization airplanes would not provide an
acceptable level of safety. No change to the final rule is necessary in
this regard.
Request To Require Operator To Revise Maintenance Manual
One operator suggests that the Boeing 747 Airplane Maintenance
Manual may contribute to the identified unsafe condition because the
Boeing overhaul manual (referenced in the maintenance manual) does not
specify that the bushings be installed in the orientation specified in
the proposed AD. The operator adds that a manual revision would be more
effective than an AD in addressing the unsafe condition.
The FAA disagrees. The operator may have been considering a now-
obsolete airplane maintenance manual; the most recent version of the
maintenance manual specifies the correct installation of the bushing.
No change to the final rule is necessary in this regard.
Request To Clarify Terminating Action Requirement
One commenter requests clarification of paragraph (c) of the
proposed AD. The commenter questions whether the intent of the
requirement is to replace all bushings--whether or not the bushing
installation is properly oriented--in accordance with Revision 5 of the
service bulletin.
The FAA agrees that clarification of the requirement might be
necessary. However, as stated previously, paragraph (c) has been
revised in the final rule. The changes made to paragraph (c) of this AD
address this commenter's concerns.
Explanation of Additional Changes to Proposed AD
Several changes have been made to the proposed AD. Paragraphs (a)
and (b) of the proposed AD specify accomplishment of a ``general visual
inspection.'' The FAA has recharacterized this as a ``detailed
inspection'' in the final rule to clarify the type of inspection
required; the inspection procedures remain the same. Note 1 in this
final rule defines a detailed inspection.
Paragraph (d) of the proposed AD has been retitled ``Part
Installation'' to more accurately identify the requirement. In
addition, the text of paragraph (d) has been revised for clarification.
Although the applicability identified in the proposed AD remains
the same, the number of airplanes affected by this final rule has been
corrected (as specified in the Cost Impact section).
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes previously
described. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Changes to 14 CFR Part 39/Effect on the Proposed AD
On July 10, 2002, the FAA issued a new version of 14 CFR part 39
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness
directives system. The regulation now includes material that relates to
altered products, special flight permits, and alternative methods of
compliance (AMOCs). The office authorized to approve AMOCs is
identified in paragraph (e) of this proposed AD.
Change to Labor Rate Estimate
We have reviewed the figures we have used over the past several
years to calculate AD costs to operators. To account for various
inflationary costs in the airline industry, we find it necessary
[[Page 47220]]
to increase the labor rate used in these calculations from $60 per work
hour to $65 per work hour. The cost impact information, below, reflects
this increase in the specified hourly labor rate.
Cost Impact
There are approximately 731 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 137 airplanes of U.S. registry
will be affected by this AD, that it will take approximately 7 work
hours per airplane to accomplish the required actions, and that the
average labor rate is $65 per work hour. The cost of required parts is
negligible. Based on these figures, the cost impact of the AD on U.S.
operators is estimated to be $62,335, or $455 per airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the requirements of this AD
action, and that no operator would accomplish those actions in the
future if this 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.
Regulatory Impact
The regulations adopted herein 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. Therefore, it
is determined that this final rule does not have federalism
implications under Executive Order 13132.
For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from the Rules Docket at the location provided under the caption
ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness
directive:
2003-16-08 Boeing: Amendment 39-13261. Docket 2001-NM-117-AD.
Applicability: Model 747-100, -100B, -100B SUD, -200B, -200C, -
200F, -300, -400, -400D, and -400F series airplanes; and Model 747SR
series airplanes; certificated in any category; line numbers 1
through 1009, except 968, 999, 1004, and 1007.
Compliance: Required as indicated, unless accomplished
previously.
To prevent the loss of an inboard trailing edge foreflap during
flight, and subsequent damage to the airplane in flight, accomplish
the following:
Inspections (Bushings Not Yet Replaced)
(a) For airplanes having line numbers 1 through 316 on which the
bushings have not been replaced prior to the effective date of this
AD: Prior to the accumulation of 5,000 total flight cycles, or
within 1,200 flight cycles after the effective date of this AD,
whichever occurs later, perform a detailed inspection for migration
of the bushings of the clevis on the inboard and outboard sequence
carriages, flap tracks 3, 4, 5, and 6 of the inboard trailing edge
foreflap. Do the inspection in accordance with Boeing Service
Bulletin 747-57-2166, Revision 5, dated May 13, 1993; or Revision 6,
dated January 16, 2003.
Note 1: 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.''
(1) For each nondiscrepant bushing (with no migration): Repeat
the inspection of that bushing at intervals not to exceed 1,200
flight cycles, until the terminating action required by paragraph
(c) of this AD has been accomplished.
(2) For any discrepant bushing: Prior to further flight, replace
the discrepant bushing with a new bushing and, if applicable,
replace the bushing marker with a new marker, in accordance with
Boeing Service Bulletin 747-57-2166, Revision 5, dated May 13, 1993;
or Revision 6, dated January 16, 2003. No further action is required
by this AD for that bushing only.
Note 2: It is not necessary to replace the marker if the marker
installed on the airplane shows the correct bushing orientation
(flange reversed, as shown in NEW CONFIGURATION, Figure 1, of Boeing
Service Bulletin 747-57-2166, Revision 5, dated May 13, 1993; and
Revision 6, dated January 16, 2003).
Inspection (Bushings Replaced)
(b) For airplanes having line numbers 1 through 316 inclusive on
which the bushings have been replaced before the effective date of
this AD in accordance with any instructions other than Boeing
Service Bulletin 747-57-2166, Revision 5, dated May 13, 1993; or
Revision 6, dated January 16, 2003; and for airplanes having line
numbers 317 through 1009 inclusive, except line numbers 968, 999,
1004, and 1007: Prior to the accumulation of 5,000 total flight
cycles, or within 1,200 flight cycles after the effective date of
this AD, whichever occurs later, perform a one-time detailed
inspection of the orientation of the bushings of the clevis on the
inboard and outboard sequence carriages, flap tracks 3, 4, 5, and 6
of the inboard trailing edge foreflap. Do the actions in accordance
with Boeing Service Bulletin 747-57-2166, Revision 5, dated May 13,
1993; or Revision 6, dated January 16, 2003. For airplanes having
line numbers 1 through 316 inclusive on which a bushing has been
replaced before the effective date of this AD in accordance with
Boeing Service Bulletin 747-57-2166, Revision 5, dated May 13, 1993;
or Revision 6, dated January 16, 2003: This AD requires no further
action for that bushing only.
(1) For each bushing that is oriented correctly: Within 5 years
after the effective date of this AD, replace the markers installed
on the airplane with new markers, as applicable, in accordance with
Boeing Service Bulletin 747-57-2166, Revision 5, dated May 13, 1993;
or Revision 6, dated January 16, 2003.
Note 3: It is not necessary to replace the marker if the marker
installed on the airplane shows the correct bushing orientation
(flange reversed, as shown in NEW CONFIGURATION, Figure 1, of Boeing
Service Bulletin 747-57-2166, Revision 5, dated May 13, 1993; and
Revision 6, dated January 16, 2003).
(2) For any bushing that is oriented incorrectly: Prior to
further flight, perform a detailed inspection of the bushing for
bushing migration, in accordance with Boeing Service Bulletin 747-
57-2166, Revision 5, dated May 13, 1993; or Revision 6, dated
January 16, 2003.
(i) For each nondiscrepant bushing (with no migration): Repeat
the inspection specified in paragraph (b)(2) of this AD at intervals
not to exceed 1,200 flight cycles,
[[Page 47221]]
until the terminating action required by paragraph (c) of this AD
has been accomplished.
(ii) For any discrepant bushing: Prior to further flight,
replace the discrepant bushing with a new bushing and, if
applicable, replace the bushing marker with a new marker, in
accordance with the service bulletin. No further action is required
by this paragraph for that bushing only.
Note 4: It is not necessary to replace the marker if the marker
installed on the airplane shows the correct bushing orientation
(flange reversed, as shown in NEW CONFIGURATION, Figure 1, of Boeing
Service Bulletin 747-57-2166, Revision 5, dated May 13, 1993; and
Revision 6, dated January 16, 2003).
Terminating Action
(c) Within 5 years after the effective date of this AD: Replace
the existing bushings of the clevis on the inboard and outboard
sequence carriages, in flap tracks 3, 4, 5, and 6 of the inboard
trailing edge foreflap. Do the actions in accordance with Boeing
Service Bulletin 747-57-2166, Revision 5, dated May 13, 1993; or
Revision 6, dated January 16, 2003. Replacement of the bushings in
accordance with Boeing Service Bulletin 747-57-2166, Revision 4,
dated December 6, 1990, or previous revision, is acceptable,
provided the bushings are inspected as required by paragraph (b) of
this AD and found to be in the correct orientation. The initial
bushing installation by the manufacturer for airplanes having line
numbers 317 and subsequent is also acceptable, provided the bushings
are inspected at the specified time and as required by paragraph (b)
of this AD and found to be in the correct orientation. Also, as
applicable, before further flight, replace the markers installed on
the airplane with new markers in accordance with Boeing Service
Bulletin 747-57-2166, Revision 5, dated May 13, 1993; or Revision 6,
dated January 16, 2003. Replacement of all bushings, and markers as
applicable, terminates the requirements of this AD.
Note 5: It is not necessary to replace the marker if the marker
installed on the airplane shows the correct bushing orientation
(flange reversed, as shown in NEW CONFIGURATION, Figure 1, of Boeing
Service Bulletin 747-57-2166, Revision 5, dated May 13, 1993; and
Revision 6, dated January 16, 2003).
Part Installation
(d) As of the effective date of this AD, no person shall install
on any airplane a carriage and toggle assembly unless the
requirements of paragraph (c) of this AD have been accomplished for
that assembly.
Alternative Methods of Compliance
(e) In accordance with 14 CFR 39.19, the Manager, Seattle ACO,
is authorized to approve alternative methods of compliance for this
AD.
Incorporation by Reference
(f) Unless otherwise specified in this AD, the actions shall be
done in accordance with Boeing Service Bulletin 747-57-2166,
Revision 5, dated May 13, 1993; or Boeing Service Bulletin 747-57-
2166, Revision 6, dated January 16, 2003. This incorporation by
reference was approved by the Director of the Federal Register in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707,
Seattle, Washington 98124-2207. Copies may be inspected at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
Effective Date
(g) This amendment becomes effective on September 12, 2003.
Issued in Renton, Washington, on July 31, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 03-19983 Filed 8-7-03; 8:45 am]
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