[Federal Register: December 8, 2004 (Volume 69, Number 235)]
[Proposed Rules]
[Page 70936-70938]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08de04-21]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2004-19812; Directorate Identifier 2003-NM-197-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100, -100B, -100B SUD,
-200B, -200C, -200F, and -300 Series Airplanes; and Model 747SP and
747SR Series Airplanes; Equipped With Pratt and Whitney Model JT9D-3 or
-7 (except -70) Series Engines
AGENCY: Federal Aviation Administration (FAA), 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 transport category airplanes. This proposed AD would
require repetitive detailed inspections to detect cracking of the aft
and forward surfaces of the bulkhead web at nacelle station 180, and
repair if necessary. This proposed AD is prompted by reports of
cracking of the web bulkhead at nacelle station 180. We are proposing
this AD to detect and correct fatigue cracking of the web bulkhead, and
consequent loss of the load path of the bulkhead at nacelle station
180, which when combined with the loss of the midspar load path, could
result in the in-flight separation of the engine and strut. Such
separation may result in secondary damage to the airplane and
consequent reduced controllability of the airplane.
DATES: We must receive comments on this proposed AD by January 24,
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, 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 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.
FOR FURTHER INFORMATION CONTACT: Technical information: Tamara
Anderson, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 917-6421; 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 relevant written data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2004-19812;
Directorate Identifier 2003-NM-197-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
[[Page 70937]]
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
.
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
We have received several reports of cracking of the web bulkhead at
nacelle station 180 on several Boeing Model 747 airplanes equipped with
Pratt and Whitney Model JT9D-3 and -7 (except -70) series engines.
These airplanes had approximately 4,100 to 18,500 total flight cycles
and 23,500 to 89,100 total flight hours. The cracking was caused by
fatigue and sonic-induced vibration. Fatigue cracking of the web
bulkhead, if not detected and corrected, could result in the loss of
the load path of the bulkhead at nacelle station 180, which when
combined with the loss of the midspar load path, could result in the
in-flight separation of the engine and strut. Such separation may
result in secondary damage to the airplane and consequent reduced
controllability of the airplane.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 747-54A2220, dated
July 31, 2003. The service bulletin describes procedures for repetitive
detailed inspections to detect cracking of the aft and forward surfaces
of the bulkhead web at nacelle station 180, and repair if necessary.
The compliance time for the repetitive detailed inspections is either
600 or 1,200 flight cycles, depending on the configuration of the
airplane. 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 you to use the service information described previously
to perform these actions, except as discussed under ``Difference
Between the Proposed AD and Service Bulletin.''
Difference Between Proposed AD and Service Bulletin
The service bulletin specifies that you should repair cracks in
accordance with the applicable 747 Structural Repair Manual (SRM), but
this proposed AD would require you to repair any crack that exceeds the
repair limits specified in the applicable SRM in one of the following
ways:
Using a method that we approve; or
Using data that meet the type certification basis of the
airplane, and that have been approved by a Boeing Company Designated
Engineering Representative who has been authorized by the FAA to make
those findings.
Costs of Compliance
This proposed AD would affect about 223 airplanes worldwide and 73
airplanes of U.S. registry. The proposed actions would take about 1
work hour per airplane, at an average labor rate of $65 per work hour.
Based on these figures, the estimated cost of the proposed AD for U.S.
operators is $4,745, or $65 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 adding the following new
airworthiness directive (AD):
Boeing: Docket No. FAA-2004-19812; Directorate Identifier 2003-NM-
197-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this AD action by January 24, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 747-100, -100B, -100B SUD, -
200B, -200C, -200F, and ``300 series airplanes; and Model 747SP and
747SR series airplanes; equipped with Pratt and Whitney Model JT9D-
3, or -7 (except for -70) series engines; as identified in Boeing
Alert Service Bulletin 747-54A2220, dated July 31, 2003;
certificated in any category.
Unsafe Condition
(d) This AD was prompted by reports of cracking of the web
bulkhead at nacelle station 180. We are issuing this AD to detect
and correct fatigue cracking of the web bulkhead, and consequent
loss of the load path of the bulkhead at nacelle station 180, which
when combined with the loss of the midspar load path, could result
in the in-flight separation of the engine and strut. Such separation
may result in secondary damage to the airplane and consequent
reduced controllability 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.
Repetitive Inspections and Repair
(f) Within 9 months after the effective date of this AD, do a
detailed inspection to detect
[[Page 70938]]
cracking of the aft and forward surfaces of the bulkhead web at
nacelle station 180, in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin 747-54A2220, dated
July 31, 2003.
(1) If no cracking is detected, repeat the detailed inspection
at the applicable intervals specified in the ``Repeat Inspection
Interval'' column of Tables 1 and 2 in Figure 1 of the service
bulletin.
(2) If any cracking is detected, before further flight, repair
the cracking in accordance with the service bulletin, except as
provided by paragraph (f)(3) of this AD. Thereafter, repeat the
detailed inspection at the applicable intervals specified in the
``Repeat Inspection Interval'' column of Tables 1 and 2 in Figure 1
of the service bulletin.
(3) If any cracking exceeds the repair limits specified in the
applicable Structural Repair Manual (referenced in the service
bulletin), before further flight, repair the cracking in accordance
with a method approved by the Manager, Seattle Aircraft
Certification Office (ACO), FAA; or in accordance with data meeting
the type certification basis of the airplane approved by a Boeing
Company Designated Engineering Representative who has been
authorized by the Manager, Seattle ACO, to make such findings. For a
repair method to be approved, the approval must specifically
reference this AD.
Alternative Methods of Compliance (AMOCs)
(g)(1) The Manager, Seattle ACO, FAA, 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 a
Boeing Company Designated Engineering Representative 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 November 30, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-26920 Filed 12-7-04; 8:45 am]
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