[Federal Register Volume 70, Number 179 (Friday, September 16, 2005)]
[Rules and Regulations]
[Pages 54612-54616]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-18313]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20364; Directorate Identifier 2004-NM-186-AD; 
Amendment 39-14274; AD 2005-19-09]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 747 airplanes. This AD requires repetitive 
inspections of the dual side braces (DSBs), underwing midspar fittings, 
and associated parts; other specified actions; and corrective actions 
if necessary. This AD also provides an optional terminating action for 
the inspections and other specified actions. This AD is prompted by 
reports of corroded, migrated, and rotated bearings for the DSBs in the 
inboard and outboard struts, a report of a fractured retainer for the 
eccentric bushing for one of the side links of a DSB, and reports of 
wear and damage to the underwing midspar fitting on the outboard strut. 
We are issuing this AD to prevent the loss of a DSB or underwing 
midspar fitting load path, which could result in the transfer of loads 
and motion to other areas of a strut, and possible separation of a 
strut and engine from the airplane during flight.

DATES: This AD becomes effective October 21, 2005.
    The incorporation by reference of a certain publication listed in 
the AD is approved by the Director of the Federal Register as of 
October 21, 2005.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    Docket: The AD docket contains the proposed AD, comments, and any 
final disposition. You can examine the 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 U.S. 
Department of Transportation, 400 Seventh Street SW., room PL-401, 
Washington, DC. This docket number is FAA-2005-20364; the directorate 
identifier for this docket is 2004-NM-186-AD.

FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6437; 
fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with an AD for certain Boeing Model 747 airplanes. That action, 
published in the Federal Register on February 14, 2005 (70 FR 7446), 
proposed to require repetitive inspections of the dual side braces 
(DSBs), underwing midspar fittings, and associated parts; other 
specified actions; and corrective actions

[[Page 54613]]

if necessary. That action also provides an optional terminating action 
for the inspections and other specified actions.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments that have been 
submitted on the proposed AD.

Support for the Proposed AD

    One commenter concurs with the content of the proposed AD.

Requests to Refer to Revised Service Bulletin and Give Credit for Prior 
Issue

    One commenter asks that the proposed AD reference Boeing Service 
Bulletin 747-54A2218, Revision 1, dated February 24, 2005. Boeing Alert 
Service Bulletin 747-54A2218, dated June 17, 2004, was referenced in 
the proposed AD as the appropriate source of service information for 
accomplishing the specified actions. The commenter states that Revision 
1 specifies that no more work is necessary on airplanes changed per the 
original issue of the service bulletin. The commenter also asks that we 
give credit for actions done in accordance with the original issue of 
the service bulletin. The commenter notes that this will prevent 
additional work for the Civil Aviation Authorities that would 
necessitate approving Revision 1 as an alternative method of 
compliance. The commenter adds that the revised information specified 
in Revision 1 may be helpful for operators in accomplishing the actions 
required by the proposed AD. A second commenter asks that credit be 
given for the initial inspection done in accordance with the original 
issue of the service bulletin.
    We agree with the commenters. We have reviewed Boeing Service 
Bulletin 747-54A2218, Revision 1, dated February 24, 2005. The 
instructions in Revision 1 are essentially the same as those in the 
original issue of the service bulletin. Accordingly, we have revised 
this AD to refer to Revision 1 of the service bulletin in the 
applicability section and as the applicable source of service 
information for accomplishing the actions required by this AD. We have 
also added a new paragraph (i) (and re-identified subsequent paragraphs 
accordingly) to give credit for actions accomplished before the 
effective date of this AD in accordance with the original issue of the 
service bulletin.

Requests to Remove/Delay Check for an Insufficient Gap/Delay Corrective 
Actions

    One commenter questions why the check for an insufficient gap 
between the underwing midspar fitting and the strut midspar fitting is 
necessary if no discrepancies are found during the proposed inspections 
of the dual side brace (DSB) bearings. The commenter states that it was 
both surprising and disappointing to learn of reported interference 
between the underwing midspar fitting and the adjacent strut midspar 
fitting. The commenter states that, while recognizing that corrective 
actions should be accomplished only if conditions warrant such actions, 
any future adopted rule should consider the inclusion of options that 
will enable corrective actions to occur during planned D-check visits 
to minimize unplanned out-of-service situations. The commenter notes 
that the proposed AD includes a check for an insufficient gap between 
those fittings within 24 months. The commenter concludes that the check 
for an insufficient gap between those fittings should only be required 
if discrepancies are found during the inspection of the DSB bearings 
per Parts 1 and 2 of the referenced service bulletin.
    A second commenter asks that paragraph (f) of the proposed AD be 
changed to postpone the requirement for accomplishing the corrective 
actions per Parts 3, 5, and 6 of the referenced service bulletin, if an 
insufficient gap is found per Part 4. The commenter states that those 
actions can be performed at its first FD-check, and until the actions 
are performed, the spring beam/wing fitting joint and DSB fitting can 
be inspected per the baseline inspection task specified in Boeing 
Service Bulletin 747-54A2182, Revision 1, dated January 8, 2004, but at 
a 3A interval. That service bulletin describes procedures for certain 
baseline inspections of the strut-to-wing attachment structure. The 
commenter adds that it has performed wing pylon modifications on more 
than 50 airplanes per Boeing Alert Service Bulletins 747-54A2156 
(referenced in AD 95-13-06, amendment 39-9286, as the appropriate 
source of service information for modification of the nacelle strut and 
wing) and 747-54A2158 (referenced in AD 95-13-07, amendment 39-9287, as 
the appropriate source of service information for modification of the 
nacelle strut and wing), concurrently with Boeing Service Bulletin 747-
57-2246, Revision 5, dated July 17, 1997. Boeing Service Bulletin 747-
57-2246 describes procedures for modification of the nacelle strut 
attachment fittings. The commenter notes that Service Bulletin 747-57-
2246 also describes procedures for checking the surface wear on the 
underwing fittings of the outboard pylon midspar that were caused by 
interference with the spring beam flanged bushings, and removal of any 
damage by spotfacing. The commenter states that only four of its 
airplanes required the spotfaces to be larger than what was allowed in 
the service bulletin, and the larger spotfaces were approved by the 
FAA. The commenter adds that cracks were never found in the wear/
spotface area; however, several of the 50 airplanes must have had the 
insufficient gap condition for many years. The commenter concludes that 
if additional surface damage occurs on the underwing midspar fittings, 
it would be detected in a timely manner when performing the proposed 
inspections.
    A third commenter, the airplane manufacturer, states that it is 
concerned with the comments regarding a no-gap condition that may exist 
during inspection, and the actions specified in paragraph (f) of the 
proposed AD per Parts 4, 5, and 6 of the referenced service bulletin. 
The commenter adds that a deferral for these actions may be justified 
for a no-gap condition, provided that no damage is found during the 
Part 4 inspection. The commenter's position is based on fleet history 
data with similar conditions, as provided by other commenters. The 
commenter may consider a change to the referenced service bulletin upon 
a recommended course of action, and will advise us accordingly. The 
commenter adds that we may choose to approve an alternative method of 
compliance (AMOC) on a case-by-case basis, at our discretion.
    We acknowledge the new information provided by the commenters. The 
airplane manufacturer has informed us that it is planning to revise the 
service bulletin to reflect this new information by the end of 2005. 
Delaying this action until after the release and approval of the 
manufacturer's planned service bulletin is not warranted. We have 
determined that the inspections must be conducted to ensure continued 
operational safety. When a new revision of the service bulletin has 
been developed, we will review that revision and consider approving it 
as an alternative method of compliance with the requirements of this 
AD. In light of this, we have determined that all the actions required 
by this AD are appropriate and warranted. No change is made to the AD 
in this regard.
    Additionally, insufficient technical justification was provided by 
the

[[Page 54614]]

commenters to justify delaying issuance of the AD; however, if 
sufficient technical justification is provided, we may approve an AMOC, 
in accordance with paragraph (j)(1) of the AD.

Requests to Change Costs of Compliance Section/Extend Compliance Time

    One commenter states that we should revise the Costs of Compliance 
section that is specified in the preamble of the proposed AD. The 
language in that section states, ``The following table provides the 
estimated costs for U.S. operators to comply with this proposed AD.'' 
The commenter notes that the table provides the cost impact of the 
required inspections, but offers no estimate of the cost impact should 
an inspection detect the specific discrepancy that is the basis for the 
proposal. The commenter states that it is well aware that the FAA's 
policy for estimating the impact of proposed ADs does not include 
publishing the impact of aircraft re-routing, preparation, access, 
correction of discrepancies found, aircraft close-up, or return-to-
flight tests and procedures, often categorizing them as ``incidental'' 
impacts. The commenter does not support that policy. The commenter 
states that, in this particular proposal, the impact of the man hours 
necessary for accomplishing the corrective action alone can be an 
order-of-magnitude greater than the per airplane cost published for 
comment. The commenter asks us to consider adopting a policy for 
proposed ADs that consistently states the per airplane impact of the 
prescribed corrective action in cases where that action is found 
necessary.
    A second commenter states that it will be subjected to a huge 
economic impact when accomplishing the actions specified in the 
proposed AD, per the referenced service bulletin, due to the mandatory 
status of the follow-up inspections and modification after an 
insufficient gap is found. The commenter adds that the follow-up 
inspections require engine and pylon removal. The commenter lists, and 
we respond to, the following factors that will make the economic impact 
of the proposed AD even greater:
    1. Experience with the modification specified in Part 3 of the 
referenced service bulletin shows that one of the DSB underwing fitting 
bolts may interfere with the modification tool. If a bolt interferes, 
it will have to be removed. Removal of a bolt requires removal of the 
WS 1140 rib to gain access to the DSB underwing fitting bolt for 
modification, which is a very time-consuming job.
    Since we issued the proposed AD, this condition has not been 
reported by any other operators. In addition, accomplishing the 
modification is only necessary if damage or cracking is found, thus 
making it an on-condition action and not part of the inspections 
required by the AD.
    2. The tooling kit specified in the referenced service bulletin 
limits the operator to modifying only one fitting on one pylon at a 
time, and not two or more pylons simultaneously. This results in 
additional downtime when more than one pylon must be modified.
    As we stated previously, accomplishing the modification is an on-
condition action. Obtaining the tooling kits necessary for 
accomplishing the modification should be addressed by operators on a 
case-by-case basis.
    3. The airplane manufacturer does not seem ready to support so many 
modifications with tooling and material kits. Currently, the airplane 
manufacturer does not have enough tooling and material kits available 
to support all operators in the 24-month timeframe allowed for the 
modification.
    We have no way of estimating how many operators will be 
accomplishing the on-condition modifications. The airplane manufacturer 
has confirmed that it will have the necessary tooling and material kits 
available to complete the on-condition actions required by the AD.
    A third commenter states that the maintenance and economic impact 
of the proposed AD could be significantly greater than that specified 
in the ``Costs of Compliance'' section. The commenter notes that a 
review of labor estimates in the referenced service bulletin revealed 
that over 500 labor hours per airplane may be required to perform the 
necessary corrective actions if problems exist at all four engine strut 
to wing attachment locations. The commenter adds that this would raise 
the labor cost for compliance to over $30K per airplane; additionally, 
material costs total over $21K per airplane, plus tooling rental 
charges in excess of $1K per day are expected.
    We do not agree with the commenters that request changing the work 
hours in this AD, because the AD reflects only the direct costs of the 
specific required actions based on the best data available from the 
manufacturer. We recognize that operators may incur incidental costs 
(such as the time for planning and associated administrative actions) 
in addition to the direct costs. The cost analysis in ADs, however, 
typically does not include incidental costs.
    The 24-month compliance time for the initial inspection required by 
this AD should allow ample time for the majority of affected operators 
to do the required actions at the same time as scheduled major airplane 
inspection and maintenance activities, which would reduce the 
additional time and costs associated with special scheduling. We note 
that the 24-month compliance time is consistent with the compliance 
time specified in the referenced service bulletin. However, operators 
may submit a request for approval of an AMOC, as specified in paragraph 
(j)(1) of this AD. The request must include data substantiating that an 
acceptable level of safety would be maintained by extending the 
compliance time. No change is made to the AD in this regard.

Conclusion

    We have carefully reviewed the available data, including the 
comments that have been submitted, 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

    There are about 1,091 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this AD.

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                 Number  of
                                           Work     Average                                       Cost per          U.S.-
                 Action                   hours    labor rate               Parts                 airplane       registered            Fleet cost
                                                    per hour                                                      airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Part 1 Inspections, per inspection             8          $65  None..........................            $520             229  $119,080, per inspection
 cycle.                                                                                                                         cycle.

[[Page 54615]]

 
Part 2 Inspections, per inspection            48           65  None..........................           3,120             229  714,480, per inspection
 cycle.                                                                                                                         cycle.
Part 4 Inspections, per inspection             4           65  None..........................             260             229  59,540, per inspection
 cycle.                                                                                                                         cycle.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this 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. 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 FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2005-19-09 Boeing: Amendment 39-14274. Docket No. FAA-2005-20364; 
Directorate Identifier 2004-NM-186-AD.

Effective Date

    (a) This AD becomes effective October 21, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to 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; as identified in Boeing Service Bulletin 747-54A2218, 
Revision 1, dated February 24, 2005.

Unsafe Condition

    (d) This AD was prompted by reports of corroded, migrated, and 
rotated bearings for the dual side braces (DSB) in the inboard and 
outboard struts, a report of a fractured retainer for the eccentric 
bushing for one of the side links of a DSB, and reports of wear and 
damage to the underwing midspar fitting on the outboard strut. We 
are issuing this AD to prevent the loss of a DSB or underwing 
midspar fitting load path, which could result in the transfer of 
loads and motion to other areas of a strut, and possible separation 
of a strut and engine from the airplane during flight.

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.

Inspections and Other Specified Actions

    (f) At the times specified in Figure 1 of Boeing Service 
Bulletin 747-54A2218, Revision 1, dated February 24, 2005, except as 
provided by paragraph (g) of this AD: Do the various inspections and 
other specified actions in the figure to detect discrepancies of the 
DSBs, underwing midspar fittings, and associated parts, by doing all 
of the actions specified in Parts 1, 2, and 4; and the applicable 
corrective actions specified in Parts 3, 5, 6, and 7; of the 
Accomplishment Instructions of the service bulletin, except as 
provided by paragraph (h) of this AD. Repeat the inspections and 
other specified actions thereafter at the intervals specified in 
Figure 1 of the service bulletin. Accomplishment of any terminating 
action specified in Figure 1 of the service bulletin terminates the 
inspections and other specified actions for the affected strut.
    (g) Where Boeing Service Bulletin 747-54A2218, Revision 1, dated 
February 24, 2005, recommends an initial compliance threshold of 
``within 24 months after the original issue date on this service 
bulletin'' for Parts 1 and 4 of the service bulletin, and of 
``within 72 months after the original issue date on this service 
bulletin'' for Part 2 of the service bulletin, this AD requires an 
initial compliance threshold of ``within 24 months after the 
effective date of this AD'' for Parts 1 and 4 of the service 
bulletin and of ``within 72 months after the effective date of this 
AD'' for Part 2 of the service bulletin.

Corrective Actions

    (h) If any damage or crack is found during any inspection or 
corrective action required by this AD, before further flight, repair 
in accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-54A2218, Revision 1, dated February 24, 2005; except, 
where the service bulletin specifies to contact Boeing, 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.

Actions Accomplished According to Previous Issue of Service Bulletin

    (i) Inspections and other specified and corrective actions 
accomplished before the effective date of this AD in accordance with

[[Page 54616]]

Boeing Alert Service Bulletin 747-54A2218, dated June 17, 2004, are 
considered acceptable for compliance with the corresponding actions 
specified in paragraph (f) of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle ACO, has the authority to approve 
AMOCs for this AD, if requested in accordance with the procedures 
found in 14 CFR 39.19.
    (2) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing 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.

Material Incorporated by Reference

    (k) You must use Boeing Service Bulletin 747-54A2218, Revision 
1, dated February 24, 2005, to perform the actions that are required 
by this AD, unless the AD specifies otherwise. The Director of the 
Federal Register approves the incorporation by reference of this 
document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To 
get copies of the service information, contact Boeing Commercial 
Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. To view 
the AD docket, go to the Docket Management Facility, U.S. Department 
of Transportation, 400 Seventh Street SW., room PL-401, Nassif 
Building, Washington, DC. To review copies of the service 
information, go to 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 September 8, 2005.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-18313 Filed 9-15-05; 8:45 am]
BILLING CODE 4910-13-P