[Federal Register Volume 71, Number 227 (Monday, November 27, 2006)]
[Rules and Regulations]
[Pages 68434-68437]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-19805]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26388; Directorate Identifier 2006-NM-234-AD; 
Amendment 39-14834; AD 2006-24-05]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Airplanes

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

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 747 airplanes. This AD requires repetitive 
inspections for any cracking of the fuselage skin in section 41 of the 
airplane, and related investigative and corrective actions if 
necessary. This AD results from a report of fatigue cracks found in the 
skin in section 41 of the fuselage, on an in-service Model 747 
airplane. We are issuing this AD to detect and correct fatigue cracks 
at the fastener rows of the fuselage skin in section 41, which could

[[Page 68435]]

join together and cause a loss of structural integrity and rapid 
decompression of the airplane.

DATES: This AD becomes effective December 12, 2006.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of December 12, 
2006.
    We must receive comments on this AD by January 26, 2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this 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.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; 
fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We have received a report indicating that fatigue cracks were found 
in the skin in section 41 of the fuselage, on an in-service Model 747 
airplane. A 10-inch skin crack and numerous smaller skin cracks in 
multiple adjacent fastener rows were found immediately aft of the left 
number 1 main entry door. The cracks occurred less than 7,000 flight 
cycles after the terminating action required by AD 2006-20-02, 
(described below), had been done. The fatigue cracks are the result of 
cyclic loading during cabin pressurization and de-pressurization. Skin 
cracks at the fastener rows in section 41 of the fuselage, if not 
detected and corrected in a timely manner, could join together and 
result in a loss of structural integrity and rapid decompression of the 
airplane.

Related AD

    On September 14, 2006, we issued AD 2006-20-02, amendment 39-14771 
(71 FR 56861, September 28, 2006) (which superseded AD 96-23-02, 
amendment 39-9807 (61 FR 57991, November 12, 1996)), for certain Boeing 
Model 747 airplanes. That AD requires inspections to detect disbonding, 
corrosion, and cracking at the longitudinal rows of fasteners in the 
bonded skin panels in section 41 of the fuselage, and repair, if 
necessary. That AD also requires inspections of airplanes that may have 
Alodine-coated rivets installed. That AD resulted from a report of 
cracking discovered in a skin lap joint that was previously inspected 
using the eddy current method. We issued that AD to prevent rapid 
decompression of the airplane due to disbonding and subsequent cracking 
of the skin panels.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2675, dated 
October 12, 2006. The alert service bulletin describes procedures for 
repetitive inspections for any cracking of the fuselage skin in section 
41 of the airplane, reports of inspection findings to Boeing, and 
related investigative and corrective actions if necessary. Repetitive 
inspections for any cracking of the fuselage skin includes using 
surface high-frequency eddy current (HFEC) inspections or, as a short-
term alternative to surface HFEC inspections, external detailed 
inspections of the skin panel around fastener heads; and open-hole HFEC 
inspections or, as a short-term alternative to open-hole HFEC 
inspections, external surface low-frequency eddy current (LFEC) 
inspections of the skin at the edge row fasteners common to an external 
doubler and a bonded internal doubler. Related investigative and 
corrective actions may involve using a surface HFEC, or an open-hole 
HFEC inspection, as applicable, on all the affected fuselage skin in 
section 41; and repairing any crack damage as given in the applicable 
Boeing 747 Structural Repair Manual, or by contacting Boeing for repair 
data.
    The alert service bulletin also specifies the following initial 
compliance times for the inspections: Within 150 flight cycles after 
the date on the alert service bulletin; before the accumulation of 
8,000 total flight cycles; or within 2,000 flight cycles after the last 
HFEC inspection, Method 1 (external Ultrasonic) or Method 2 (internal 
detailed) disbond inspection as given in Boeing Alert Service Bulletin 
747-53A2409 (which is referenced in AD 2006-20-02 as the appropriate 
source of service information for doing the actions for that AD); 
whichever occurs last. The inspections must be repeated at intervals 
not to exceed 2,000 flight cycles for the HFEC inspections, and not to 
exceed 150 flight cycles for the alternative detailed and LFEC 
inspections that are also not to be repeated more than nine times 
before the applicable HFEC inspection is started.

FAA's Determination and Requirements of this AD

    The unsafe condition described previously is likely to exist or 
develop on other airplanes of the same type design. For this reason, we 
are issuing this AD to detect and correct fatigue cracks at fastener 
rows, which could join together and cause a loss of structural 
integrity and rapid decompression of the airplane. This AD requires 
accomplishing the actions specified in the service information 
described previously, except as discussed under ``Difference Between 
the AD and the Alert Service Bulletin.'' The AD also requires sending 
the inspection results of each inspection to the manufacturer.

Difference Between the AD and the Alert Service Bulletin

    The alert service bulletin specifies that you may contact the 
manufacturer for instructions on how to repair certain conditions, but 
this AD requires 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.

Interim Action

    This is considered to be interim action. The manufacturer has 
advised that it currently is developing a new inspection program that 
will expand the size of the inspection area and add repetitive 
inspections that will address the unsafe condition addressed by this AD 
and AD 2006-20-02. Once this new inspection program is developed, 
approved, and available, we may consider additional rulemaking.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we have found that notice and opportunity for 
public comment before

[[Page 68436]]

issuing this AD are impracticable, and that good cause exists to make 
this AD effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety and was not preceded by notice and an opportunity for 
public comment; however, we invite you to submit any relevant written 
data, views, or arguments regarding this AD. Send your comments to an 
address listed in the ADDRESSES section. Include ``Docket No. FAA-2006-
26388; Directorate Identifier 2006-NM-234-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD that might 
suggest a need to modify it.
    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 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 may review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you may visit 
http://dms.dot.gov.

Examining the Docket

    You may 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 Docket Management System 
receives them.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. 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.
    We are issuing this rulemaking 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 AD will not have federalism 
implications under Executive Order 13132. This AD will 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 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 AD and placed it in the AD docket. 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2006-24-05 Boeing: Amendment 39-14834. Docket No. FAA-2006-26388; 
Directorate Identifier 2006-NM-234-AD.

Effective Date

    (a) This AD becomes effective December 12, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 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-
53A2675, dated October 12, 2006.

Unsafe Condition

    (d) This AD results from a report that fatigue cracks were found 
in the skin in section 41 of the fuselage, on an in-service Model 
747 airplane. We are issuing this AD to detect and correct fatigue 
cracks at the fastener rows of the fuselage skin in section 41, 
which could join together and cause a loss of structural integrity 
and rapid decompression 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, Investigative and Corrective Actions

    (f) At the applicable compliance time specified in paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 747-53A2675, 
dated October 12, 2006, do the applicable inspection for any 
cracking of the fuselage skin in the section 41 area, and do all 
applicable related investigative and corrective actions, by 
accomplishing all the actions specified in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2675, dated 
October 12, 2006, except as provided by paragraphs (g) and (h) of 
this AD. Repeat the applicable inspection at intervals not to exceed 
those specified in paragraph 1.E. of the service bulletin. If any 
crack is found, do all applicable related investigative and 
corrective actions before further flight.
    (g) Where Boeing Alert Service Bulletin 747-53A2675, dated 
October 12, 2006, recommends an initial inspection threshold 
relative to the date on the service bulletin, this AD requires the 
initial inspection threshold relative to the effective date of this 
AD.
    (h) If any crack is found during any inspection required by this 
AD, and Boeing Alert Service Bulletin 747-53A2675, dated October 12, 
2006, specifies to contact Boeing for appropriate action: Before 
further flight, repair the cracking using a method approved in 
accordance with the procedures specified in paragraph (j) of this 
AD.

Inspection Reports

    (i) Submit a report of the findings (both positive and negative) 
of the inspections required by paragraph (f) of this AD to Boeing 
Commercial Airplanes Group, Attention: Manager, Airline Support, 
P.O. Box 3707, Seattle, Washington 98124-2207, at the applicable 
time specified in paragraph (i)(1) or (i)(2) of this AD. The report 
must include the inspection results, a description of any 
discrepancies/crack found, the airplane serial

[[Page 68437]]

number, and the number of landings and flight hours on the airplane. 
Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 
et seq.), the Office of Management and Budget (OMB) has approved the 
information collection requirements contained in this AD and has 
assigned OMB Control Number 2120-0056.
    (1) For each inspection done after the effective date of this 
AD: Submit the report within 10 days after the inspection.
    (2) For each inspection accomplished prior to the effective date 
of this AD: Submit the report within 10 days after the effective 
date of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle Aircraft Certification Office (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) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.
    (3) 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 Commercial Airplanes 
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 repair must meet the certification basis 
of the airplane, and the approval must specifically refer to this 
AD.

Material Incorporated by Reference

    (k) You must use Boeing Alert Service Bulletin 747-53A2675, 
dated October 12, 2006, to perform the actions that are required by 
this AD, unless the AD specifies otherwise. The Director of the 
Federal Register approved the incorporation by reference of this 
document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for a copy of this service information. You 
may review copies at the Docket Management Facility, U.S. Department 
of Transportation, 400 Seventh Street SW., Room PL-401, Nassif 
Building, Washington, DC; on the Internet at http://dms.dot.gov; or 
at the National Archives and Records Administration (NARA). For 
information on the availability of this material at the NARA, call 
(202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on November 13, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-19805 Filed 11-24-06; 8:45 am]
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