[Federal Register Volume 71, Number 89 (Tuesday, May 9, 2006)]
[Proposed Rules]
[Pages 26888-26890]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-7016]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24695; Directorate Identifier 2006-NM-035-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-200B, 747-200C, 747-
200F, 747-300, and 747SR Series 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 747-200B, 747-200C, 747-200F, 747-300, and 
747SR series airplanes. This proposed AD would require doing repetitive 
inspections of engine struts 1 through 4, as applicable, for heat 
discoloration, cracking, buckling, or wrinkling. This proposed AD also 
would require a conductivity test to detect the extent of the heat 
damage and an inspection to detect cracking of the heat-discolored, 
buckled, or wrinkled area; and repair; if necessary. This proposed AD 
results from reports of heat damage and cracking of the skin and 
internal structure adjacent to and aft of the precooler exhaust vent on 
several engine struts. We are proposing this AD to detect and correct 
cracking, buckling, wrinkling, or heat damage of the skin and internal 
structure of the engine struts, which could result in extensive damage 
to the engine struts and consequent possible separation of an engine 
from the airplane during flight.

DATES: We must receive comments on this proposed AD by June 23, 2006.

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.
     Governmentwide 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.

[[Page 26889]]

    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for the service information identified in this 
proposed 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 in the ADDRESSES section. Include the docket number ``FAA-2006-
24695; Directorate Identifier 2006-NM-035-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 
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 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.

Discussion

    We have received reports of heat damage and cracking of the skin 
and internal structure adjacent to and aft of the precooler exhaust 
vent on 14 engine struts on in-service airplanes. These airplanes had 
the terminating modification specified in Boeing Service Bulletin 747-
54-2163 incorporated, which installed external titanium doublers and 
internal frame reinforcement to originally address high-temperature air 
from the precooler exhaust vent of the engine struts. However, the 
reported damage has occurred in unmodified areas, as well as modified 
areas. High-temperature air from the precooler exhaust vent could heat 
up and potentially anneal (reducing the strength) the skin and internal 
structure of the engine struts, which could result in cracking, 
buckling, wrinkling, or heat damage of the skin and internal structure 
of the engine struts. Such cracking, buckling, wrinkling, or heat 
damage, if not detected and corrected, could result in extensive damage 
to the engine strut and consequent possible separation of an engine 
from the airplane during flight.

Other Relevant Rulemaking

    We have previously issued AD 95-13-07, amendment 39-9287 (60 FR 
33336, June 28, 1995), applicable to certain Boeing Model 747 series 
airplanes. That AD requires modifications of the nacelle strut and wing 
structure, inspections and checks to detect discrepancies, and 
correction of discrepancies. The actions required by that AD must be 
done in accordance with Boeing Alert Service Bulletin 747-54A2158, 
dated November 30, 1994. That service bulletin refers to several 
service bulletins as additional sources of service information for 
doing the actions required by AD 95-13-07. One of those additional 
sources is Boeing Service Bulletin 747-54-2163.
    We have determined that the actions specified in Boeing Service 
Bulletin 747-54-2163 continue to prevent failure of the strut and 
subsequent loss of the engine. Therefore, this proposed AD would not 
affect the requirements of AD 95-13-07.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 747-54-
2223, dated January 26, 2006. The service bulletin describes the 
following procedures:
     Doing repetitive detailed inspections of engine struts 1 
through 4, as applicable, for heat discoloration, cracking, buckling, 
or wrinkling;
     Doing a conductivity test to detect the extent of the heat 
damage and a penetrant inspection or high frequency eddy current (HFEC) 
inspection to detect cracking of the heat-discolored, buckled, or 
wrinkled area, if necessary;
     Contacting Boeing for repair instructions if necessary.

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. For this reason, 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 Proposed AD and Service Bulletin.''

Differences Between the Proposed AD and Service Bulletin

    The service bulletin specifies to contact the manufacturer for 
instructions on how to repair certain conditions, but this proposed AD 
would require repairing 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 Commercial Airplanes Delegation Option Authorization 
Organization whom we have authorized to make those findings.

Costs of Compliance

    There are about 112 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 33 airplanes of 
U.S. registry. The proposed detailed inspections would take about 4 or 
8 work hours per airplane (depending on the airplane configuration), at 
an average labor rate of $80 per work hour. Based on these figures, the 
estimated cost of the proposed AD for U.S. operators is $10,560 or 
$21,120, or $320 or $640 per airplane, per inspection cycle (depending 
on the airplane configuration).

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,

[[Page 26890]]

``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 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, 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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-24695; Directorate Identifier 2006-NM-
035-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by June 23, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-200B, 747-200C, 747-
200F, 747-300, and 747SR series airplanes, certificated in any 
category; as identified in Boeing Special Attention Service Bulletin 
747-54-2223, dated January 26, 2006.

Unsafe Condition

    (d) This AD results from reports of heat damage and cracking of 
the skin and internal structure adjacent to and aft of the precooler 
exhaust vent on several engine struts on in-service airplanes. We 
are issuing this AD to detect and correct cracking, buckling, 
wrinkling, or heat damage of the skin and internal structure of the 
engine struts, which could result in extensive damage to the engine 
struts and consequent possible separation of an 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.

Service Bulletin

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-54-2223, dated January 26, 2006.

Repetitive Detailed Inspections

    (g) Within 18 months after the effective date of this AD, do a 
detailed inspection of engine struts 1 through 4, as applicable, for 
heat discoloration, cracking, buckling, or wrinkling, in accordance 
with the service bulletin. Repeat the detailed inspection thereafter 
at intervals not to exceed 18 months.

Corrective Actions

    (h) If any heat discoloration, buckling, or wrinkling is found 
during any detailed inspection required by paragraph (g) of this AD, 
before further flight, do a conductivity test to detect the extent 
of the heat damage and a penetrant inspection or high frequency eddy 
current inspection to detect cracking of the heat-discolored, 
buckled, or wrinkled area, in accordance with the service bulletin.
    (1) If the conductivity test results are within the limits 
specified in the service bulletin and no cracking is detected, 
before further flight, repair any buckled or wrinkled area using a 
method approved in accordance with the procedures specified in 
paragraph (j) of this AD. Heat discoloration does not need to be 
repaired if the conductivity test results of the heat-discolored 
area are within the specified limits in the service bulletin.
    (2) If the conductivity test results are outside the limits 
specified in the service bulletin or if any cracking is detected, 
before further flight, repair any cracking, heat discoloration, or 
buckled or wrinkled area using a method approved in accordance with 
the procedures specified in paragraph (j) of this AD.
    (i) If any cracking is found during any detailed inspection 
required by paragraph (g) of this AD, before further flight, repair 
the cracking using a method approved in accordance with the 
procedures specified in paragraph (j) 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.

    Issued in Renton, Washington, on April 28, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E6-7016 Filed 5-8-06; 8:45 am]
BILLING CODE 4910-13-P