FR Doc 05-2762

[Federal Register: February 14, 2005 (Volume 70, Number 29)]
[Proposed Rules]
[Page 7446-7449]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14fe05-23]

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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

[[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]

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