[Federal Register Volume 69, Number 235 (Wednesday, December 8, 2004)]
[Proposed Rules]
[Pages 70936-70938]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-26920]


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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, [email protected].

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]
BILLING CODE 4910-13-P