[Federal Register: September 16, 2005 (Volume 70, Number 179)]
[Proposed Rules]
[Page 54668-54671]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16se05-22]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-22423; Directorate Identifier 2005-NM-068-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-200C and -200F 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 supersede an existing airworthiness
directive (AD) that applies to certain Boeing Model 747-200C and -200F
series airplanes. The existing AD currently requires repetitive
inspections to find fatigue cracking in the upper chord of the upper
deck floor beams, and repair if necessary. For certain airplanes, the
existing AD also provides an optional repair/modification, which
extends certain repetitive inspection intervals. This proposed AD would
reduce the compliance time for all initial inspections and reduce the
repetitive interval for a certain inspection. This proposed AD is
prompted by new reports of cracks in the upper deck floor beams
occurring at lower flight cycles. We are proposing this AD to find and
fix cracking in certain upper deck floor beams. Such cracking could
extend and sever floor beams at a floor panel attachment hole location
and could result in rapid decompression and loss of controllability of
the airplane.

DATES: We must receive comments on this proposed AD by October 31,
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.
     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. This docket
number is FAA-2005-22423; the directorate identifier for this docket is
2005-NM-068-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 under ADDRESSES. Include ``Docket No. FAA-2005-22423;
Directorate Identifier 2005-NM-068-AD'' at the beginning of your
comments. We specifically invite

[[Page 54669]]

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.


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 Docket Management System
(DMS) receives them.

Discussion

    On January 29, 2004, we issued AD 2004-03-11, amendment 39-13455
(69 FR 5920, February 9, 2004), for certain Boeing Model 747-200C and -
200F series airplanes. That AD requires repetitive inspections to find
fatigue cracking in the upper chord of certain upper deck floor beams,
and repair if necessary. For certain airplanes, that AD also provides
an optional repair/modification, which extends certain repetitive
inspection intervals. That AD was prompted by a report of fatigue
cracking of the station (STA) 340 upper deck floor beam. We issued that
AD to find and fix cracking in certain upper deck floor beams. Such
cracking could extend and sever floor beams at a floor panel attachment
hole location and could result in rapid decompression and loss of
controllability of the airplane.

Actions Since Existing AD Was Issued

    Since we issued AD 2004-03-11, we have received new reports of
cracks in the upper deck floor beams on several airplanes. The
airplanes had accumulated between 19,580 and 23,561 total flight
cycles. In one case, the aft reinforcing strap of the upper chord of
the floor beam at station 520 was found severed at 19,580 total flight
cycles. Another airplane with 19,687 total flight cycles had
significant cracks in the same area. The threshold for the initial
inspection required by AD 2004-03-11 is 22,000 total flight cycles.
Therefore, we have determined that the initial inspections and a
certain repetitive inspection required by that AD need to be done
earlier to detect cracks in the upper deck floor beams in a timely
manner.

Relevant Service Information

    We have reviewed Revision 1 of Boeing Alert Service Bulletin 747-
53A2439, dated March 10, 2005. The inspections, repair, and optional
repair/modification described in Revision 1 are essentially identical
to those in the original issue, which is referenced in AD 2004-03-11 as
the appropriate source of service information for the required actions.
Revision 1 reduces the compliance time for all initial inspections and
reduces the repetitive inspection interval for surface high frequency
eddy current (HFEC) inspection of the upper deck floor beams (header
beams) at STAs 440 and 520. The compliance time for accomplishing the
inspection of repaired areas ranges between 5,000 and 15,000 flight
cycles depending on the diameter of the fastener hole. 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

    The unsafe condition described previously is likely to exist or
develop on other airplanes of the same type design that may be
registered in the U.S. at some time in the future. We are proposing to
supersede AD 2004-03-11. This proposed AD would continue to require
repetitive inspections to find fatigue cracking in the upper chord of
the upper deck floor beams, and repair if necessary. This proposed AD
would also continue to provide, for certain airplanes, an optional
repair/modification, which extends certain repetitive inspection
intervals. This proposed AD would also reduce the compliance time for
all initial inspections and reduce the repetitive interval for a
certain inspection. The actions would be required to be accomplished in
accordance with the service bulletin 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 provides the following information in Note 9
of the Accomplishment Instructions: ``For the purposes of this service
bulletin, do not count flight-cycles with a cabin pressure differential
of 2.0 psi or less. However, any flight-cycle with momentary spikes in
cabin pressure differential above 2.0 psi must be included as a full-
pressure flight-cycle.'' We have determined that an adjustment of
flight cycles due to a lower cabin differential pressure is not
substantiated and will not be allowed for use in determining the flight
cycle threshold for this proposed AD.
    The service bulletin specifies that you may contact the
manufacturer for instructions on how to repair certain conditions, but
this proposed AD would require 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 whom we
have authorized to make those findings.
    Although the Accomplishment Instructions of the service bulletin
describe procedures for submitting inspection results to Boeing, this
proposed AD would not require that action. We do not need this
information from operators.

Change to Existing AD

    This proposed AD would retain certain requirements of AD 2004-03-
11. Since AD 2004-03-11 was issued, 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
------------------------------------------------------------------------
                                             Corresponding  requirement
       Requirement in AD 2004-03-11             in  this proposed AD
------------------------------------------------------------------------
Paragraph (a).............................  Paragraphs (f) and (g).
Paragraph (b).............................  Paragraph (h).
------------------------------------------------------------------------

Costs of Compliance

    There are about 78 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 21 airplanes of
U.S. registry.

[[Page 54670]]

    The inspections that are required by AD 2004-03-11 and retained in
this proposed AD take about 29 work hours per airplane, at an average
labor rate of $65 per work hour. Based on these figures, the estimated
cost of the currently required inspections for U.S. airplanes is
$39,585, or $1,885 per airplane, per inspection cycle.

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 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 39-13455 (69 FR
5920, February 9, 2004) and adding the following new airworthiness
directive (AD):

Boeing: Docket No. FAA-2005-22423; Directorate Identifier 2005-NM-
068-AD.

Comments Due Date

    (a) The Federal Aviation Administration must receive comments on
this AD action by October 31, 2005.

Affected ADs

    (b) This AD supersedes AD 2004-03-11, amendment 39-13455.

Applicability

    (c) This AD applies to Boeing Model 747-200C and -200F series
airplanes, certificated in any category, as listed in Boeing Alert
Service Bulletin 747-53A2439, dated July 5, 2001.

Unsafe Condition

    (d) This AD was prompted by new reports of cracks in the upper
deck floor beams occurring at lower flight cycles. We are issuing
this AD to find and fix cracking in certain upper deck floor beams,
which could extend and sever floor beams at a floor panel attachment
hole location and could result in rapid decompression and loss of
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.

Requirements of AD 2004-03-11

Initial Compliance Time at a New Reduced Threshold

    (f) At the earliest of the times specified in paragraphs (f)(1)
through (f)(3) of this AD, do the inspection required by paragraph
(g) of this AD.
    (1) Before the accumulation of 22,000 total flight cycles, or
within 1,000 flight cycles after March 15, 2004 (the effective date
of AD 2004-03-11), whichever occurs later.
    (2) For airplanes with 17,000 or more total flight cycles as of
the effective date of this AD: Before the accumulation of 18,000
total flight cycles, or within 90 days after the effective date of
this AD, whichever occurs later.
    (3) For airplanes with fewer than 17,000 total flight cycles as
of the effective date of this AD: Before the accumulation of 15,000
total flight cycles, or within 1,000 flight cycles after the
effective date of this AD, whichever occurs later.

Inspections at Reduced Intervals for Certain Floor Beams and Repair

    (g) Do the applicable inspection to find fatigue cracking in the
upper chord of the upper deck floor beams as specified in Part 1
(Open-Hole High Frequency Eddy Current (HFEC) Inspection Method) or
Part 2 (Surface HFEC Inspection Method) of the Work Instructions of
Boeing Alert Service Bulletin 747-53A2439, dated July 5, 2001. Do
the inspections per the service bulletin. As of the effective date
of this AD, the actions must be done per the Work Instructions of
Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March
10, 2005.
    (1) If any crack is found, before further flight, repair per
Part 3 (Upper Chord Repair) of the Work Instructions of the service
bulletin; except where the service bulletin specifies to contact
Boeing for appropriate action, before further flight, repair
according to a method approved by the Manager, Seattle Aircraft
Certification Office (ACO), FAA; or according to data meeting the
certification basis of the airplane approved by an a Boeing Company
Designated Engineering Representative (DER) or Authorized
Representative for the Boeing Delegation Option Authorization
Organization who has been authorized by the Manager, Seattle ACO, to
make such findings. For a repair method to be approved by the
Manager, Seattle ACO, as required by this paragraph, the Manager's
approval letter must specifically reference this AD. Do the
applicable inspection of the repaired area per Part 1 of the Work
Instructions of the service bulletin at the applicable time per Part
3 of the Work Instructions of the service bulletin, and repeat the
applicable inspection at the applicable interval per Figure 1 of the
service bulletin. As of the effective date of this AD, do the
applicable inspection of the repaired area per Parts 1 and 6 of the
Work Instructions of the service bulletin at the applicable time per
Table 1 of Part 3 of the Work Instructions of the service bulletin,
and repeat the applicable inspection thereafter at intervals not to
exceed 3,000 flight cycles.
    (2) If no crack is found, repeat the applicable inspection per
paragraph (g) of this AD at the applicable time specified in
paragraphs (g)(2)(i) through (g)(2)(iii) of this AD. As an option,
accomplishment of paragraph (h)(1) or (h)(2) of this AD, before
further flight, extends the threshold for the initiation of the
repetitive inspections required by this paragraph.
    (i) If the open-hole HFEC inspection method was used: Repeat
that inspection at intervals not to exceed 3,000 flight cycles.
    (ii) If the surface HFEC inspection method was used at stations
340 through 420 inclusive and station 500: Repeat that inspection at
intervals not to exceed 750 flight cycles.
    (iii) If the surface HFEC inspection method was used at stations
440 and 520: Repeat that inspection at the earlier of the times
specified in paragraphs (g)(2)(iii)(A) and (g)(2)(iii)(B) of this
AD, and thereafter at intervals not to exceed 250 flight cycles.

[[Page 54671]]

    (A) Within 750 flight cycles since the last surface HFEC
inspection required by paragraph (g) of this AD.
    (B) Within 250 flight cycles after the effective date of this
AD.

Optional Repair/Modification

    (h) For airplanes on which the inspection required by paragraph
(g) of this AD is done per Part 1 of the Work Instructions of Boeing
Alert Service Bulletin 747-53A2439, dated July 5, 2001, or Revision
1, dated March 10, 2005; and on which no cracking is found:
Accomplishment of the actions specified in either paragraph (h)(1)
or (h)(2) of this AD extends the threshold for the initiation of the
repetitive inspections required by paragraph (g)(2) of this AD. For
airplanes on which the inspection required by paragraph (g) of this
AD is done per Part 2 of the Work Instructions of Boeing Alert
Service Bulletin 747-53A2439, dated July 5, 2001, or Revision 1,
dated March 10, 2005; and on which no cracking is found:
Accomplishment of the actions specified in paragraph (h)(1) of this
AD extends the threshold for the initiation of the repetitive
inspections required by paragraph (g)(2) of this AD.
    (1) Do the applicable repair per Part 3 of the Work Instructions
of the service bulletin. At the applicable time specified in Table 1
of Part 3 of the Work Instructions of the service bulletin, do the
applicable inspection of the repaired area per Part 1 of the Work
Instructions of the service bulletin. Repeat the inspection
thereafter within the applicable interval per Figure 1 of the
service bulletin. As of the effective date of this AD, the actions
must be done per Parts 1, 3, and 6 of the Work Instructions of
Boeing Alert Service Bulletin 747-53A2439, Revision 1, dated March
10, 2005, as applicable, and repeat the applicable inspection
thereafter at intervals not to exceed 3,000 flight cycles.
    (2) Do the modification of the attachment hole of the floor
panel per Figure 5 of the service bulletin. Within 10,000 flight
cycles after accomplishment of the modification, do the inspection
of the modified area per Part 1 of the Work Instructions of the
service bulletin. Repeat the inspection thereafter within the
applicable interval per Figure 1 of the service bulletin. As of the
effective date of this AD, the actions must be done per Figure 5 and
Part 1 of the Work Instructions of Boeing Alert Service Bulletin
747-53A2439, Revision 1, dated March 10, 2005, and repeat the
inspection thereafter at intervals not to exceed 3,000 flight
cycles.

Determining the Number of Flight Cycles for Compliance Time

    (i) For the purposes of calculating the compliance threshold and
repetitive intervals for actions required by paragraphs (f), (g), or
(h) of this AD: As of the effective date of this AD, all flight
cycles, including the number of flight cycles in which cabin
differential pressure is at 2.0 pounds per square inch (psi) or
less, must be counted when determining the number of flight cycles
that have occurred on the airplane.

No Reporting Requirement

    (j) Although the service bulletin referenced in this AD
specifies to submit certain information to the manufacturer, this AD
does not include that requirement.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office
(SACO), 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 an
Authorized Representative for the Boeing 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.
    (3) AMOCs approved previously according to AD 2004-03-11 are
approved as AMOCs for the corresponding provisions of paragraphs (f)
and (g) of this AD.

    Issued in Renton, Washington, on September 7, 2005.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-18403 Filed 9-15-05; 8:45 am]

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