[Federal Register Volume 68, Number 153 (Friday, August 8, 2003)]
[Rules and Regulations]
[Pages 47218-47221]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-19983]


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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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