[Federal Register: November 5, 2004 (Volume 69, Number 214)]
[Proposed Rules]
[Page 64517-64520]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05no04-17]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2004-19538; Directorate Identifier 2003-NM-99-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to supersede an existing airworthiness
directive (AD) for certain Boeing Model 747 series airplanes. That AD
currently requires inspections to detect cracks in the front spar
pressure bulkhead chord, and repair, if necessary. This proposed AD
would require repetitive high frequency eddy current (HFEC) inspections
of the body station (BS) 1000 bulkhead chord for cracks, repetitive
detailed inspections of the bathtub fittings, if installed, for cracks,
and corrective action, if necessary. Accomplishment of new inspections
would end the inspections of the existing AD. This proposed AD would
also revise the applicability of the existing AD to include additional
[[Page 64518]]
airplanes. This proposed AD is prompted by reports of cracks in the BS
1000 bulkhead chord. We are proposing this AD to detect and correct
fatigue cracks in the BS 1000 bulkhead chord, which, if not repaired
before they reach critical length, could result in the failure of the
adjacent structure and skin and lead to in-flight depressurization of
the airplane.
DATES: We must receive comments on this proposed AD by December 20,
2004.
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.
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, P.O. Box 3707, Seattle, Washington 98124-
2207.
You can examine the contents of this AD docket on the Internet at
http://dms.dot.gov, or 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.
FOR FURTHER INFORMATION CONTACT: Technical information: Nick Kusz,
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6432; fax (425) 917-6590.
Plain language information: Marcia Walters, marcia.walters@faa.gov.
SUPPLEMENTARY INFORMATION:
Docket Management System (DMS)
The FAA has implemented new procedures for maintaining AD dockets
electronically. As of May 17, 2004, new AD actions are posted on DMS
and assigned a docket number. We track each action and assign a
corresponding directorate identifier. The DMS AD docket number is in
the form ``Docket No. FAA-2004-99999.'' The Transport Airplane
Directorate identifier is in the form ``Directorate Identifier 2004-NM-
999-AD.'' Each DMS AD docket also lists the directorate identifier
(``Old Docket Number'') as a cross-reference for searching purposes.
Comments Invited
We invite you to submit any written relevant data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2004-19538;
Directorate Identifier 2003-NM-99-AD'' at the beginning 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 received 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 our
docket 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 the 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.
We are reviewing the writing style we currently use in regulatory
documents. We are interested in your comments on whether the style of
this document is clear, and your suggestions to improve the clarity of
our communications that affect you. You can get more information about
plain language at http://www.faa.gov/language and http://www.plainlanguage.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
On April 19, 1990, we issued AD 90-09-09, amendment 39-6586 (55 FR
17928, April 30, 1990), for certain Boeing Model 747 series airplanes
(a correction of that AD was published in the Federal Register on May
21, 1990 (55 FR 20894)). That AD requires repetitive high frequency
eddy current (HFEC) inspections to detect cracks in the front spar
pressure bulkhead chord, and repair, if necessary. That AD was prompted
by a determination that accomplishing a certain modification may result
in fuel leakage from the wing center section fuel tank. We issued that
AD to prevent a potential fire hazard in the forward cargo compartment.
Actions Since Existing AD was Issued
Since we issued AD 90-09-09 (applicable to Boeing Model 747-100, -
100B, -100B SUD, -200B, -200C, and -200F series airplanes, line numbers
1 through 201 inclusive), we have received reports of cracks in the
body station (BS) 1000 bulkhead chord of Boeing Model 747 series
airplanes after line number 201. We have also received reports of
cracking in the chords of airplanes that received the chord replacement
per Boeing Service Bulletin 747-53-2362, dated March 26, 1992 (for
Model 747-100, -100B, -100B SUD, -200B, -200C, and -200F series
airplanes, line numbers 1 through 201 inclusive). Boeing Service
Bulletin 747-53-2362 was intended to address cracking in the chord.
Fatigue cracking in the BS 1000 bulkhead chord, if not repaired before
they reach critical length, could result in the failure of the adjacent
structure and skin and lead to in-flight depressurization of the
airplane.
Related ADs Due to Common Access
On May 23, 2000, we issued AD 2000-11-07 (65 FR 34932, June 1,
2000), applicable to certain Boeing Model 747-200, -300, and -400
series airplanes, that requires repetitive HFEC inspections to detect
cracking of the front spar web of the center section of the wing, and
repair, if necessary.
On October 19, 2001, we issued AD 2001-22-04 (66 FR 54422, October
29, 2001), applicable to all Boeing Model 747 series airplanes, that
requires repetitive inspections for cracking of the fuselage skin
adjacent to the drag splice fitting, and follow-on actions, if
necessary.
The inspections in the above ADs may be accomplished concurrently
with this proposed AD due to common access but they are not required by
this AD.
[[Page 64519]]
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 747-53A2471, dated
March 27, 2003. The service bulletin describes procedures for
performing repetitive HFEC inspections of the BS 1000 bulkhead chord
for cracks; performing repetitive detailed inspections of the bathtub
fittings, if installed, for cracks; and corrective action, if
necessary. Accomplishing the inspections would end the inspections
required by AD 90-09-09. The corrective action includes replacing the
BS 1000 bulkhead chord with a new chord and replacing the bathtub
fittings with new bathtub fittings.
Accomplishment of the actions specified in the service bulletin is
intended to adequately address the identified unsafe condition.
The service bulletin also recommends concurrent accomplishment, due
to common access, of the inspections specified in Boeing Service
Bulletin 747-53A2444 (Boeing Service Bulletin 747-53A2444, Revision 1,
dated June 15, 2000; and Boeing Alert Service Bulletin 74753A2444,
Revision 2, dated May 24, 2001, are listed as relevant sources of
service information for AD 2001-22-04); Boeing Service Bulletin 747-57-
2297; and Boeing Service Bulletin 747-57A2298 (Boeing Alert Service
Bulletin 747-57A2298, Revision 1, dated September 12, 1996; Boeing
Service Bulletin 747-57A2298, Revision 2, dated October 2, 1997; and
Boeing Alert Service Bulletin 747-57A2298, Revision 3, dated January 7,
1999; are listed as relevant sources of service information for AD
2000-11-07). These service bulletins are not required by this AD.
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 products
of this same type design. Therefore, we are proposing this AD, which
would supersede AD 90-09-09. This proposed AD would continue to require
repetitive HFEC inspections to detect cracks in the front spar pressure
bulkhead chord, and repair, if necessary. This proposed AD would also
require repetitive HFEC inspections of BS 1000 bulkhead chord for
cracks, repetitive detailed inspections of the bathtub fittings, if
installed, for cracks, and corrective action, if necessary.
Accomplishment of new inspections would end the inspections of the
existing AD. The proposed AD would also revise the applicability of the
existing AD to include additional airplanes. This proposed AD would
require you to use the service information described previously to
perform these actions except as discussed under ``Difference Between
the Proposed AD and the Service Bulletin.''
Difference Between the Proposed AD and the Service Bulletin
Operators should note that, although the service bulletin specifies
that the manufacturer may be contacted for disposition of certain
repair conditions, this proposed AD would require the repair of those
conditions to be accomplished per a method approved by the FAA.
Clarification of Inspection Type
Where Boeing Alert Service Bulletin 747-53A2471, dated March 27,
2003, specifies to do a ``detailed visual inspection,'' this proposed
AD specifies to do a ``detailed inspection.'' We have also added a note
to the proposed AD to clarify the definition of detailed inspection.
Changes to Existing AD
This proposed AD would retain the requirements of AD 90-09-09.
However, the AD format has been revised, and certain paragraphs have
been rearranged. As a result, the corresponding paragraph identifiers
have changed in this proposed AD, as listed in the following table:
Revised Paragraph Identifiers
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Corresponding requirement
Requirement in AD 90-09-09 in this proposed AD
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Paragraph A............................... Paragraph (f).
Paragraph B............................... Paragraph (g).
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Costs of Compliance
There are about 1,350 Model 747 series airplanes worldwide of the
affected design. This proposed AD would affect about 245 airplanes of
U.S. registry.
The actions that are required by AD 90-09-09 and retained in this
proposed AD take about 84 work hours per airplane, at an average labor
rate of $65 per work hour. We estimate 102 airplanes of U.S. registry
are affected by AD 90-09-09. Based on these figures, the estimated cost
of the currently required actions is $556,920, or $5,460 per airplane,
per inspection cycle.
The new proposed inspections would take about 14 work hours per
airplane, at an average labor rate of $65 per work hour. Based on these
figures, the estimated cost of the new actions specified in this
proposed AD for U.S. operators is $222,950, or $910 per airplane, per
inspection cycle.
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 removing amendment 39-6586 (55 FR
20894, May 21, 1990), and adding the following new airworthiness
directive (AD):
Boeing: Docket No. FAA-2004-19538; Directorate Identifier 2003-NM-
99-AD.
Comments Due Date
(a) The Federal Aviation Administration must receive comments on
this airworthiness directive (AD) action by December 20, 2004.
Affected ADs
(b) This AD supersedes AD 90-09-09, amendment 39-6586 (55 FR
20894, May 21, 1990.
Applicability
(c) This AD applies to Model 747 series airplanes, line numbers
1 through 1307
[[Page 64520]]
inclusive, 1309 through 1312 inclusive, and 1314; certificated in
any category.
Unsafe Condition
(d) This AD was prompted by reports of cracks in the body
station (BS) 1000 bulkhead chord. We are issuing this AD to detect
and correct fatigue cracks in the BS 1000 bulkhead chord, which, if
not repaired before they reach critical length, could result in the
failure of the adjacent structure and skin and lead to in-flight
depressurization of the airplane.
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.
Restatement of Requirements of AD 90-09-09
(f) For airplanes listed in Boeing Service Bulletin 747-53-2064,
Revision 4, dated September 23, 1983, that have not been modified in
accordance with Boeing Service Bulletin 747-53-2064, dated July 25,
1972: Within the next 1,000 landings after October 15, 1984 (the
effective date of AD 84-18-06, amendment 39-4912), or prior to the
accumulation of 10,000 landings, whichever occurs later, and
thereafter at intervals not to exceed 7,000 landings, conduct a high
frequency eddy current (HFEC) inspection of the chord to detect
cracks between stringers S-37 and S-39 at the chord radius, heel,
and flanges adjacent to the fastener holes identified for inspection
in Boeing Service Bulletin 747-53-2064, Revision 4, dated September
23, 1983. If cracks are found in the pressure bulkhead chord,
accomplish the repair in accordance with the service bulletin before
further flight. Repair of cracks along the chord radius under 5
inches in length, or across a chord flange that have not severed the
chord flange, may be deferred 1,000 landings by stop drilling and
reinspecting for crack progression every 200 landings using HFEC. If
crack progression is found, repair in accordance with the service
bulletin prior to further flight. Inspections are to continue at
intervals not to exceed 7,000 landings after repair.
(g) For airplanes listed in Boeing Service Bulletin 747-53-2064,
Revision 4, dated September 23, 1983, that have been modified in
accordance with Boeing Service Bulletin 747-53-2064, dated July 25,
1972: Within the next 1,000 landings after October 15, 1984, or
prior to the accumulation of 10,000 landings after the modification,
whichever is later, and thereafter at intervals not to exceed 10,000
landings, conduct an HFEC inspection to detect cracks in the front
spar pressure bulkhead lower chord heel from stringers S-37 to S-39,
and conduct an ultrasonic inspection to detect cracks in the
fuselage skin originating at the indicated fastener holes beneath
the forward drag splice fitting flanges, in accordance with the
service bulletin. If any cracks are found, repair in accordance with
Boeing Service Bulletin 747-53-2064, Revision 4, dated September 23,
1983, before further flight. Inspections are to continue at
intervals not to exceed 10,000 landings after repair.
New Requirements of This AD
Initial Inspections
(h) At the later of the times specified in paragraph (h)(1),
(h)(2), or (h)(3) of this AD: Except as provided by paragraph (i) of
this AD, perform an HFEC inspection of BS 1000 bulkhead chord for
cracks, a detailed inspection of the bathtub fittings, if installed,
for cracks, and corrective action, as applicable, by accomplishing
all the actions specified in the Accomplishment Instructions of
Boeing Alert Service Bulletin 747-53A2471, dated March 27, 2003. Any
applicable corrective action must be done before further flight.
Accomplishment of the HFEC and detailed inspections required by
paragraph (h) of this AD ends the requirements of paragraphs (f) and
(g) of this AD.
Note 1: For the purposes of this AD, a detailed inspection is
``an intensive examination of a specific item, installation, or
assembly to detect damage, failure, or irregularity. Available
lighting is normally supplemented with a direct source of good
lighting at an intensity deemed appropriate. Inspection aids such as
mirrors, magnifying lenses, etc., may be necessary. Surface cleaning
and elaborate procedures may be required.''
(1) Prior to the accumulation of 10,000 total flight cycles.
(2) Within 18 months after the effective date of this AD.
(3) For airplanes on which the repair (i.e., chord replacement)
has been accomplished in accordance with Boeing Service Bulletin
747-53-2362, dated March 26, 1992, or in accordance with paragraph
(f) or (g) of this AD (i.e., per Boeing Service Bulletin 747-53-
2064, Revision 4, dated September 23, 1983): Within 3,000 flight
cycles after the replacement was accomplished.
Note 2: Repairs (i.e., chord replacement) accomplished prior to
the effective date of this AD in accordance with Boeing Service
Bulletin 747-53-2064, Revision 1, dated May 18, 1973; Revision 2,
dated February 22, 1974; Revision 3, dated September 13, 1974;
Revision 5, dated July 23, 1987; or Revision 6, dated June 22, 1989;
are considered to be applicable to the inspection threshold
specified in paragraph (h)(3) of this AD.
(i) If any crack is found during any inspection required by
paragraph (h) of this AD, and Boeing Alert Service Bulletin 747-
53A2471, dated March 27, 2003, specifies contacting Boeing for
additional information: Before further flight, repair per a method
approved by the Manager, Seattle Aircraft Certification Office
(ACO), FAA. For a repair method to be approved by the Manager,
Seattle ACO, as required by this paragraph, the Manager's approval
letter must specifically refer to this AD.
Repetitive Inspections
(j) Except as provided by paragraph (k) of this AD, repeat the
inspections required by paragraph (h) of this AD thereafter at
intervals not to exceed 3,000 flight cycles.
(k) For airplanes on which both the chord replacement and
bathtub fitting replacement were done in accordance with the
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2471, dated March 27, 2003: Repeat the inspections required by
paragraph (h) of this AD within 6,000 flight cycles after
accomplishing both replacements. Thereafter repeat the inspections
at intervals not to exceed 3,000 flight cycles.
Alternative Methods of Compliance (AMOC)
(l)(1) In accordance with 14 CFR 39.19, the Manager, Seattle
ACO, FAA, is authorized to AMOCs for this AD.
(2) AMOCs, approved previously in accordance with AD 90-09-09,
amendment 39-6586, are approved as AMOCs with paragraph (f) or (g)
of this AD, as applicable.
Issued in Renton, Washington, on October 26, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-24726 Filed 11-4-04; 8:45 am]
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