[Federal Register: October 8, 2008 (Volume 73, Number 196)]
[Proposed Rules]
[Page 58903-58906]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08oc08-26]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-1071; Directorate Identifier 2008-NM-093-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 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 airplanes. The
existing AD currently requires repetitive inspections to detect
evidence of wear damage in the area at the interface between the
vertical stabilizer seal and fuselage skin, and corrective actions, if
necessary. The existing AD also provides for an optional terminating
action for the repetitive inspections. For all airplanes, this proposed
AD would require doing repetitive inspections for wear damage and
cracks of the fuselage skin in the interface area of the vertical
stabilizer seal and fuselage skin, doing a detailed inspection for wear
damage and cracks of the surface of any skin repair doubler in the
area, and doing corrective actions. For airplanes on which the fuselage
skin has been blended to remove wear damage, this proposed AD would
require doing repetitive external detailed inspections or high
frequency eddy current inspections for cracks of the blended area of
the fuselage skin, and corrective actions if necessary. This proposed
AD results from reports of wear damage on airplanes with fewer than
8,000 total flight cycles. In addition, there have been three reports
of skin wear damage on airplanes that applied BMS 10-86 Teflon-filled
coating (terminating action per AD 2002-26-15). We are issuing this AD
to detect and correct wear damage and cracks of the fuselage skin in
the interface area of the vertical stabilizer seal and fuselage skin in
sections 46 and 48, which could cause in-flight depressurization of the
airplane.
DATES: We must receive comments on this proposed AD by November 24,
2008.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
For service information identified in this AD, contact Boeing
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.
Examining the AD Docket
You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Office (telephone 800-647-5527) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.
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:
Comments Invited
We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2008-1071;
Directorate Identifier 2008-NM-093-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD because of those comments.
We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.
Discussion
On December 24, 2002, we issued AD 2002-26-15, amendment 39-13003
(68 FR 476, January 6, 2003), for certain Boeing Model 747 series
airplanes. That AD requires repetitive inspections to detect evidence
of skin wear damage in the interface area of the vertical stabilizer
seal and fuselage skin, and corrective actions, if necessary. The
existing AD also provides for an optional terminating action for the
repetitive inspections. That AD resulted from reports of wear damage at
the interface area of the vertical stabilizer seal and fuselage skin in
sections 46 and 48. We issued that AD to detect and correct wear damage
of the fuselage skin, which could result in thinning and cracking of
the fuselage skin, and consequent in-flight depressurization of the
airplane.
Actions Since Existing AD Was Issued
Since we issued AD 2002-26-15, we have received several reports of
skin wear damage on airplanes with less than 8,000 total flight cycles.
As a result, Boeing has revised the initial inspection threshold of the
repetitive inspections to 20,000 total flight hours. In addition, there
have been three reports of skin wear damage on airplanes that have
received the Boeing Material Specifications (BMS) 10-86 Teflon-filled
coating application (terminating action per AD 2002-26-15). We have
concluded that the one-time Teflon-filled coating application does not
provide the necessary skin wear resistance; therefore, the terminating
action no longer terminates the repetitive inspections. The
requirements of 2002-26-15 do not adequately address the identified
unsafe condition of that AD.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 747-53A2478,
Revision 1, dated March 27, 2008. The service bulletin describes the
following procedures:
For all airplanes: Do repetitive external inspections for
wear damage and cracks of the fuselage skin at the interface area of
the vertical stabilizer
[[Page 58904]]
seal and fuselage skin, and do a detailed inspection for wear damage
and cracks of the surface of any repair doubler installed in the area.
For airplanes on which the fuselage skin has been blended
to remove wear damage: Do repetitive external detailed inspections or
high frequency eddy current inspections for cracks of the blended area
of the fuselage skin.
If no wear damage or crack is found: Before further
flight, apply BMS 10-86 Teflon-filled coating.
If any wear damage or crack is found: Before further
flight, measure the depth of the wear and location, repair any wear
damage and crack, and apply BMS 10-86 Teflon-filled coating.
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 develop on other airplanes of the
same type design. For this reason, we are proposing this AD, which
would supersede AD 2002-26-15. This proposed AD would retain the
requirements of that AD and also require accomplishing the actions
described previously, except as discussed under ``Differences Between
the Proposed AD and the Service Bulletin.''
Differences Between the Proposed AD and Service Bulletin
The service bulletin specifies to contact the manufacturer for
actions if corrosion resistant steel rubstrips are installed in the
interface area of the vertical stabilizer seal and fuselage skin, but
this proposed AD would require contacting the FAA for inspections using
a method that we approve.
Costs of Compliance
There are about 917 airplanes of the affected design in the
worldwide fleet. The following table provides the estimated costs for
U.S. operators to comply with this proposed AD.
Estimated Costs
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Number of U.S.-
Action Work hours Average labor Parts Cost per airplane registered Fleet cost
rate per hour airplanes
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Inspection (required by AD 2002-26- 12 $80 None................. $960, per inspection 253 $242,880, per
15). cycle. inspection cycle.
Inspection and application of BMS 8 80 None................. $640, per inspection 165 $105,600, per
10-86 Teflon-filled coating (new cycle. inspection cycle.
proposed action).
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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 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
removing amendment 39-13003 (68 FR 476, January 6, 2003) and adding the
following new airworthiness directive (AD):
Boeing: Docket No. FAA-2008-1071; Directorate Identifier 2008-NM-
093-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by November
24, 2008.
Affected ADs
(b) This AD supersedes AD 2002-26-15.
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-
53A2478, Revision 1, dated March 27, 2008.
[[Page 58905]]
Unsafe Condition
(d) This AD results from reports of skin wear damage on
airplanes with fewer than 8,000 total flight cycles. In addition,
there have been three reports of skin wear damage on airplanes on
which BMS 10-86 Teflon-filled coating was applied (terminating
action per AD 2002-26-15). We are issuing this AD to detect and
correct wear damage and cracks of the fuselage skin in the interface
area of the vertical stabilizer seal and fuselage skin in sections
46 and 48, which could cause in-flight depressurization 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 2002-26-15
Inspections for Damage/Corrective Actions
(f) For airplanes identified in Boeing Alert Service Bulletin
747-53A2478, dated February 7, 2002: Prior to the accumulation of
15,000 total flight cycles, or within 1,200 flight cycles after
February 10, 2003 (the effective date of AD 2002-26-15), whichever
occurs later, perform a detailed inspection to detect evidence of
wear damage of the fuselage skin at the interface area of the
vertical stabilizer seal and fuselage skin, per the service
bulletin.
(1) If no wear damage of the fuselage skin is detected or any
existing blendout is within the structural repair manual (SRM)
allowable damage limits: Repeat the detailed inspection at intervals
not to exceed 6,000 flight cycles.
(2) If any wear damage of the fuselage skin is detected or any
existing blendout exceeds the allowable damage limits specified in
the SRM: Before further flight, repair the vertical stabilizer seal
interface and refinish the skin with BMS 10-86 Teflon-filled
coating, per the alert service bulletin. Accomplishment of the
repair and refinishing is terminating action for the repetitive
inspections required by paragraph (f)(1) of this AD.
Note 1: For the purposes of this AD, a detailed inspection is
defined as: ``An intensive visual examination of a specific
structural area, system, installation, or assembly to detect damage,
failure, or irregularity. Available lighting is normally
supplemented with a direct source of good lighting at intensity
deemed appropriate by the inspector. Inspection aids such as mirror,
magnifying lenses, etc., may be used. Surface cleaning and elaborate
access procedures may be required.''
Previously Accomplished Inspections and Terminating Action
(g) For airplanes identified in Boeing Alert Service Bulletin
747-53A2478, dated February 7, 2002: Inspections and terminating
action done before February 10, 2003, per Boeing Service Bulletin
747-53-2192, dated July 21, 1981, are acceptable for compliance with
the corresponding actions required by paragraph (f) of this AD,
provided BMS 10-86 Teflon-filled coating was used, and the new
allowable damage limits specified in Boeing Alert Service Bulletin
747-53A2478, dated February 7, 2002, are met.
New Requirements of This AD
New Service Bulletin Revision
(h) The term ``service bulletin,'' as used in paragraphs (i)
through (l) of this AD, means Boeing Alert Service Bulletin 747-
53A2478, Revision 1, dated March 27, 2008, unless otherwise
specified.
New Repetitive Inspections
(i) Except as provided by paragraph (j) of this AD: At the
applicable times specified in Table 1 of this AD, do the actions
specified in paragraphs (i)(1) and (i)(2) of this AD, as applicable.
Accomplishing the initial inspection specified in paragraph (i)
terminates the requirements of paragraph (f) of this AD.
(1) For all airplanes: Do the actions specified in paragraphs
(i)(1)(i) and (i)(1)(ii) of this AD, as applicable.
(i) Do repetitive external detailed inspections for wear damage
and cracks of the fuselage skin in the interface area of the
vertical stabilizer seal and fuselage skin, in accordance with the
Accomplishment Instructions of the service bulletin.
(ii) Where a skin repair doubler is present in the interface
area of the vertical stabilizer seal and fuselage skin, do a
detailed inspection for wear damage and cracks of the surface of the
repair doubler.
(2) For airplanes that have reduced skin thickness in Section 46
due to blending without reinforcement: Do repetitive external
detailed inspections or high frequency eddy (HFEC) current
inspections for cracks of the blended area of the fuselage skin, in
accordance with the Accomplishment Instructions of the service
bulletin.
Table 1--Compliance Times
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Compliance time (whichever occurs later)
Action ----------------------------------------------------- Repeat interval (not
Threshold Grace period to exceed)
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For actions required by paragraph Prior to the accumulation Within 6,000 flight 7,500 flight hours.
(i)(1) of this AD. of 20,000 total flight hours after the
hours since the date of effective date of
issuance of the original this AD.
airworthiness certificate
or the date of issuance of
the original export
certificate of
airworthiness, or within
7,500 flight hours after
the last inspection of
this AD, whichever occurs
later.
For actions required by paragraph Prior to the accumulation Within 1,000 flight 1,200 flight cycles
(i)(2) of this AD. of 20,000 total flight cycles after the for external detailed
cycles since the date of effective date of inspection, or 6,000
issuance of the original this AD. flight cycles for
airworthiness certificate HFEC inspection.
or the date of issuance of
the original export
certificate of
airworthiness, or within
6,000 flight cycles after
the initial blend,
whichever occurs later.
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Exception to the Repetitive Inspections
(j) If corrosion-resistant steel rubstrips are installed in the
interface area of the vertical stabilizer seal and fuselage skin:
Within the applicable compliance times specified in paragraph (i) of
this AD, inspect the fuselage skin using a method approved in
accordance with the procedures specified in paragraph (m) of this
AD.
For No Wear Damage or Cracks Found: Apply Teflon
(k) If no wear damage or crack is found in the fuselage skin
during any inspection required by paragraph (i) of this AD: Before
further flight, apply Boeing Material Specifications (BMS) 10-86
Teflon-filled coating in accordance with the Accomplishment
Instructions of the service bulletin.
For Any Wear Damage or Crack Found: Applicable Corrective Actions
(l) If any wear damage or crack is found in the fuselage skin
during any inspections required by paragraph (i) of this AD: Before
further flight, after the inspection required by paragraph (i), do
the actions specified in paragraphs (l)(1), (l)(2), and (l)(3) of
this AD, in accordance with the Accomplishment Instructions of the
service bulletin.
(1) Measure the depth of the wear and record the location.
(2) Repair any wear damage and any crack.
[[Page 58906]]
(3) Apply BMS 10-86 Teflon-filled coating.
Alternative Methods of Compliance (AMOCs)
(m)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S,
FAA, Seattle ACO, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone (425) 917-6437; fax (425) 917-6590; has the
authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19.
(2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
(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 September 26, 2008.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-23824 Filed 10-7-08; 8:45 am]
BILLING CODE 4910-13-P