[Federal Register Volume 70, Number 29 (Monday, February 14, 2005)]
[Proposed Rules]
[Pages 7446-7449]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-2762]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20364; Directorate Identifier 2004-NM-186-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 747 airplanes. This proposed AD would require 
repetitive inspections of the dual side braces (DSBs), underwing 
midspar fittings, and associated parts; other specified actions; and 
corrective actions if necessary. This proposed AD also provides an 
optional terminating action for the inspections and other specified 
actions. This proposed 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 proposing 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: We must receive comments on this proposed AD by March 31, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW, Nassif Building, room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, PO Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street, SW., room PL-
401, on the plaza level of the Nassif Building, 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:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-20364; 
Directorate Identifier 2004-NM-186-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments submitted by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.

Examining the Docket

    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 DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

Discussion

    We have received reports of corroded, migrated, and rotated 
bearings for the dual side braces (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 on Boeing Model 747-400 
and Model 747SP series airplanes. These conditions, if not corrected, 
could result in the loss of the DSB or underwing midspar fitting load 
path, which could result in the transfer of loads and motion to other 
areas of a

[[Page 7447]]

strut, and possible separation of a strut and engine from the airplane 
during flight.
    The subject area on certain Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400D, 747-400F, 
and 747SR series airplanes is of a similar type design to those on the 
affected Model 747-400 and 747SP series airplanes. Therefore, all of 
these models may be subject to the same unsafe condition.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-54A2218, dated 
June 17, 2004. The service bulletin describes procedures for repetitive 
inspections of the DSBs, underwing midspar fittings, and associated 
parts; other specified actions; and corrective actions if necessary. 
This proposed AD also provides an optional terminating action for the 
repetitive actions.
    The service bulletin specifies that the initial inspections of the 
DSBs and of the underwing midspar fitting be done within 24 months 
after the release date of the service bulletin. The service bulletin 
also specifies that the initial corrosion removal and re-lubrication of 
the DSB bearings be done within 72 months after the release date of the 
service bulletin (unless directed by the findings of the initial 
inspections of the DSBs to be done earlier). The service bulletin 
specifies that repetitive intervals range between 24 months and 72 
months for the aforementioned actions. The service bulletin also 
specifies that the corrective actions be done before further flight or 
within 24 months of finding certain conditions.
    The service bulletin specifies that the following actions for the 
inboard and outboard struts are applicable to Groups 1-3 airplanes, and 
that only the actions for the inboard struts are applicable to Group 4 
airplanes:

Part 1--Dual Side Brace Inspections

    The service bulletin describes the following DSB inspections:
     Do a detailed inspection of the bearing spherical ball for 
corrosion, corrosion pitting, and corrosion products.
     Do a detailed inspection for migration and rotation of the 
bearing outer race.
     Do a detailed inspection for cracks or fracture of the 
eccentric bushing retainer.
    The service bulletin specifies that if no discrepancies are found 
during the inspections, either repeat Part 1 and Part 4, or do Part 4 
and Part 3 (terminating action).
    The service bulletin specifies that if any discrepancies are found 
during the inspections, the corrective actions include doing Part 4 and 
Part 2; or doing Part 4 and Part 3 (terminating action); as applicable.
    The service bulletin also specifies that Part 2 may be done instead 
of Part 1.

Part 2--Bearing Corrosion Removal and Re-Lubrication

    The service bulletin describes the following inspections and rework 
of the DSB bearings and associated parts, and other specified actions.
     Do a detailed inspection of the bearing for migration and 
rotation.
     Do a detailed inspection for cracks or fracture of the 
swaged lips.
     Do a detailed inspection for cracks or fracture of the 
eccentric bushing retainer.
     Do a detailed inspection of the eccentric bushing for 
damage.
     Do a detailed inspection of the bushing and fuse pin for 
damage.
     Do a detailed inspection of the bolt for damage.
     The other specified actions include determining if the 
amount of play in the bearing exceeds specified limits, determining if 
corrosion exceeds specified limits, and removing corrosion, as 
applicable; and lubricating the spherical ball and inside of the outer 
race.
    The service bulletin specifies that if no discrepancies are found 
during the actions specified in Part 2: Either repeat both Part 1 and 
Part 4, and Part 4 and Part 2; or do Part 4 and Part 3 (terminating 
action).
    The service bulletin specifies that if any discrepancies are found 
during the actions specified in Part 2, the corrective actions include 
repeating both Part 1 and Part 4, and Part 4 and Part 2; or doing Part 
4 and Part 3 (terminating action); as applicable. The corrective 
actions also include replacing any damaged bushings/eccentric bushings/
fuse pins/bolts with new or serviceable bushings/eccentric bushings/
fuse pins/bolts; and contacting Boeing for additional instructions.

Part 3--Dual Side Brace Bearing Replacement and Side Link Modification

    The service bulletin describes procedures for replacing the strut 
and wing side DSB bearings with new or serviceable strut and wing side 
bearings (includes, for Groups 3 and 4, installing cups per Part 7), 
modifying side links, and doing related investigative and corrective 
actions.
    Related investigative actions include the following inspections:
     Detailed inspection of the fuse pin for damage.
     Detailed inspection for damage of the strut fitting lug 
bore and chamfers.
     Fluorescent penetrant inspection (FPI) or high frequency 
eddy current inspection for cracks of the strut fitting lug bore and 
chamfers.
     Detailed inspection for cracking of the swaged lip of the 
bearing.
     FPI of the eccentric bushing bore in the link for cracks, 
corrosion, and damage.
     Detailed inspection of the bushing for damage.
    Corrective actions include replacing any damaged fuse pin with a 
new or serviceable fuse pin; contacting Boeing for additional 
instructions; oversizing the lug bore; and replacing any damaged 
bearing with a new or serviceable bearing.

Part 4--Underwing Midspar Fitting Inspection

    The service bulletin describes an inspection to determine the gap 
between the underwing midspar fitting and strut midspar fitting.
    The service bulletin specifies that if the gap is within limits 
specified in the service bulletin no further action is required.
    The service bulletin specifies that if the gap is not within limits 
specified in the service bulletin, the corrective action includes doing 
Part 4 and Part 3 (terminating action) or doing Part 3, Part 5, and 
Part 6 (terminating action), as applicable.

Part 5--Underwing Midspar Fitting Inspection and Rework

    The service bulletin describes procedures to do a detailed 
inspection of the underwing midspar fitting lugs, strut spring beam 
lugs and bushings, and strut fitting lugs for damage, and corrective 
action if necessary.
    The corrective action includes reworking the underwing midspar 
fitting, spring beams, and strut fitting; and contacting Boeing for 
additional instructions.

Part 6--Dual Side Brace Fitting and Underwing Midspar Fitting Tension 
Bolt Inspection

    The service bulletin describes procedures to do a detailed 
inspection of the dual side brace fitting and underwing fittings for 
missing or fractured tension bolts or for broken sealant around the 
fasteners; and do a detailed inspection of the visible areas of the 
underwing fitting lugs and strut fitting lugs or spring beam lugs for 
damage; and corrective action if necessary. The corrective action is

[[Page 7448]]

repairing any damage and contacting Boeing for additional instructions.

Part 7--Vapor Seal Web Cup Installation

    The service bulletin describes procedures for Groups 3 and 4 to 
install cups for the vapor seal web.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. Therefore, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Differences Between the AD and the Service Bulletin.''
    The FAA is not proposing to mandate the optional terminating action 
for several reasons:
    1. Accessing the areas for inspection at the intervals is easily 
accomplished.
    2. The inspection items are easily performed by means of a detailed 
inspection.
    3. Long-term continued operational safety in this case will be 
adequately ensured by repetitive inspections to prevent the loss of a 
DSB or underwing midspar fitting load path.

Differences Between the Proposed AD and the Service Bulletin

    The service bulletin specifies that you may contact the 
manufacturer for instructions on how to repair certain conditions, but 
this proposed AD would require you to repair those conditions in one of 
the following ways:
     Using a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by an Authorized Representative 
for the Boeing Delegation Option Authorization Organization who has 
been authorized by the FAA to make those findings.

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 proposed AD.

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

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. 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.
    This rulemaking is promulgated 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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. 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 proposed 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, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Boeing: Docket No. FAA-2005-20364; Directorate Identifier 2004-NM-
186-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by March 31, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B,

[[Page 7449]]

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 Alert Service Bulletin 747-54A2218, dated June 17, 2004.

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 Corrective Action

    (f) At the times specified in Figure 1 of Boeing Alert Service 
Bulletin 747-54A2218, dated June 17, 2004, 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 dual 
side braces, 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.
    (g) Where Boeing Alert Service Bulletin 747-54A2218, dated June 
17, 2004, 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.
    (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 Alert 
Service Bulletin 747-54A2218, dated June 17, 2004; 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 approval must specifically refer to this AD.

Alternative Methods of Compliance (AMOCs)

    (i)(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 approval must specifically refer to this AD.

    Issued in Renton, Washington, on February 7, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-2762 Filed 2-11-05; 8:45 am]
BILLING CODE 4910-13-P