[Federal Register Volume 75, Number 186 (Monday, September 27, 2010)]
[Proposed Rules]
[Pages 59167-59170]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-24175]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2010-0858; Directorate Identifier 2010-NM-183-AD]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Model 737-600, -700,
-700C, -800, -900, and -900ER Series Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain Model 737-600, -700, -700C, -800, -900, and -900ER series
airplanes. This proposed AD would require modifying the thrust reverser
inner walls, inspecting for damage of the upper and lower inner wall
insulation blankets, measuring the electrical conductivity on the
aluminum upper compression pads 2 and 3 as applicable, inspecting for
discrepancies of the inner wall of the thrust reverser, and corrective
actions if necessary. This proposed AD would also require, for certain
airplanes, doing various concurrent actions (including replacing the
inner wall blanket insulation, installing updated full-authority
digital electronic control software, and modifying the thrust reverser
inner wall and insulation blankets). This proposed AD results from
reports of heat damage to the inner wall of the thrust reversers. We
are proposing this AD to detect and correct such heat damage, which
could result in separation of adjacent components and consequent
structural damage to the airplane, damage to other airplanes, and
injury to people on the ground.
DATES: We must receive comments on this proposed AD by November 12,
2010.
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 proposed AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management,
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; e-mail [email protected];
Internet https://www.myboeingfleet.com. You may review copies of the
referenced service information at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information
on the availability of this material at the FAA, call 425-227-1221.
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
[[Page 59168]]
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: Chris Parker, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office
(ACO), 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone
425-917-6496; 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-2010-0858;
Directorate Identifier 2010-NM-183-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
We have received reports of heat-related damage to the inner wall
of the thrust reverser. During an inspection of a thrust reverser, one
operator found heat damage at different locations of the inner wall: At
the top, in the area of the number 2 and number 3 upper compression
pads, and at the lower aft edge. A flight test at Boeing showed that
the temperatures applied to the inner walls of the thrust reversers are
too high. Higher temperatures are due to hot precooler air leakage
between the inner wall of the thrust reverser and the insulation
blankets and heat transfer through the upper compression pad area and
the fireseal bracket support flange. Heat damage to the thrust reverser
inner wall, if not corrected, could result in separation of adjacent
components and consequent structural damage to the airplane, damage to
other airplanes, and injury to people on the ground.
Relevant Service Information
We have reviewed the service bulletins identified in the following
table.
Service Information
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Service Bulletin Revision level Date
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Boeing Service Bulletin Original........ March 25, 2010.
737[dash]78[dash]1082.
Boeing Service Bulletin Original........ May 12, 2010.
737[dash]78[dash]1088.
Boeing Service Bulletin 2............... June 7, 2010.
737[dash]78[dash]1079.
Boeing Service Bulletin 4............... June 16, 2005.
737[dash]78[dash]1069.
Boeing Service Bulletin 2............... October 7, 1999.
737[dash]78[dash]1063.
CFM CFM56-7B Service Bulletin Original........ March 30, 2007.
73[dash]0135.
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Boeing Service Bulletin 737-78-1082 describes procedures for
modifying the thrust reverser inner wall by drilling a hole through the
inner wall behind the number 3 upper compression pad, and installing a
bushing, applying sealant to areas of the insulation blankets, and
installing flange insulation assemblies at the top aft edge of the
upper insulation blanket.
Boeing Service Bulletin 737-78-1088 describes procedures for the
following:
Detailed inspection for damage of the engine side and
inner wall side of the upper and lower insulation blankets.
Measurement of the electrical conductivity on the aluminum
upper compression pads 2 and 3, as applicable.
Inspections for discrepancies of the inner wall of the
thrust reverser, including an ultrasonic inspection of the thrust
reverser inner wall for interplay delamination and skin-to-core
disbond.
Detailed inspection, for certain airplanes, of the thrust
reverser inner wall for signs of heat damage.
Detailed inspection of the thrust reverser inner wall for
indications of loose fasteners where the inner wall attaches to the
hinge beam and at the fasteners for the compression pads.
Corrective actions, including repairing or replacing
damaged insulation blankets and repairing the thrust reverser inner
wall (including replacing loose fasteners and contacting Boeing for a
repair procedure), and replacing any unserviceable compression pad with
a new one.
Boeing Service Bulletin 737-78-1079 describes procedures for
essentially the same actions (including inspections and modification)
specified in Boeing Service Bulletins 737-78-1082 and 737-78-1088.
Boeing Service Bulletin 737-78-1082 also specifies the concurrent
accomplishment of the actions specified in Boeing Service Bulletin 737-
78-1063: replacement of the inner wall blanket insulation.
Boeing Service Bulletin 737-78-1082 also specifies the concurrent
accomplishment of the actions specified in CFM CFM56-7B Service
Bulletin 73-0135: installation of updated full-authority digital
electronic control (FADEC) software.
Boeing Service Bulletin 737-78-1088 specifies the concurrent
accomplishment of the actions specified in Boeing Service Bulletin 737-
78-1069: modification of the thrust reverser inner walls and insulation
blankets. The modification involves installing additional supports on
the inner wall of the thrust reverser for the attachment of the
insulation blankets, installing new brackets to attach the forward edge
of the upper and lower insulation blankets, installing additional
attachment grommets to the blankets, and sealing the blankets at the
forward edge of the fan duct inner walls.
FAA's Determination and Requirements of This Proposed AD
We are proposing this AD because we evaluated all relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of these same type
designs. This proposed AD would require accomplishing the actions
specified in the service information described previously, except as
discussed below.
Differences Between the Proposed AD and Service Information
Although Boeing Service Bulletin 737-78-1088 specifies that
operators may contact the manufacturer for disposition of certain
repair conditions, this proposed AD would require operators to repair
those conditions using a method approved by the FAA.
[[Page 59169]]
Clarification of Certain Terminology
Where Boeing Service Bulletin 737-78-1088 refers to
``unsatisfactory'' findings, this proposed AD assumes those parts or
locations are ``unserviceable.''
Costs of Compliance
We estimate that this proposed AD would affect 710 airplanes of
U.S. registry. The following table provides the estimated costs for
U.S. operators to comply with this proposed AD, at an average labor
rate of $85 per hour.
Estimated Costs
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Number of U.S.-
Actions (Service Bulletin) Work hours Parts Cost per product registered airplanes Fleet cost
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Modification (Boeing Service 14 per engine........ $2,065 or 3,702...... $4,445 or 6,082..... 710................. Up to $4,318,220.
Bulletin 737[dash]78[dash]1082).
Insulation replacement (Boeing 18 per engine........ 0.................... 3,060............... 15.................. 45,900
Service Bulletin
737[dash]78[dash]1063).
Software update (CFM CFM56-7B 1.................... 0.................... 85.................. Up to 710........... Up to 60,350.
Service Bulletin 73[dash]0135).
Inspections (Boeing Service 35................... 0.................... 2,975............... 710................. 2,112,250
Bulletin 737-78-1088).
Modifications (Boeing Service 110.................. 0.................... 9,350............... 306................. 2,861,100
Bulletin 737-78-1069).
Inspections and modification 37 per engine........ 2,070 or 3,391....... 8,360 or 9,681...... Optional action..... Optional action.
(Boeing Service Bulletin 737-78-
1079) (if done as an option to
Boeing Service Bulletin 737-78-
1088 and Boeing Service Bulletin
737-78-1082).
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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 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 this 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.
You can find our regulatory evaluation and the estimated costs of
compliance in the AD Docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, 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 AD:
The Boeing Company: Docket No. FAA-2010-0858; Directorate Identifier
2010-NM-183-AD.
Comments Due Date
(a) We must receive comments by November 12, 2010.
Affected ADs
(b) None.
Applicability
(c) This AD applies to The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes; certificated in any
category; as identified in Boeing Service Bulletin 737-78-1082,
dated March 25, 2010.
Subject
(d) Air Transport Association (ATA) of America Code 78: Engine
exhaust.
Unsafe Condition
(e) This AD results from reports of heat damage to the inner
wall of the thrust reversers. The Federal Aviation Administration is
issuing this AD to detect and correct such heat damage, which could
result in separation of adjacent components and consequent
structural damage to the airplane, damage to other airplanes, and
injury to people on the ground.
Compliance
(f) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Modification of Thrust Reverser Inner Wall
(g) Except as required by paragraph (m) of this AD: Within 24
months after the effective date of this AD, modify the thrust
reverser inner wall, in accordance with the Accomplishment
Instructions of Boeing Service Bulletin 737-78-1082, dated March 25,
2010.
Actions Concurrent With Paragraph (g)
(h) Before or concurrently with accomplishment of the
requirements of paragraph (g) of this AD, do the actions
[[Page 59170]]
specified in paragraphs (h)(1) and (h)(2) of this AD, as applicable.
(1) For Model 737-600, -700, and -800 series airplanes
identified in Boeing Service Bulletin 737-78-1063, Revision 2, dated
October 7, 1999: Replace the inner wall blanket insulation, in
accordance with the Accomplishment Instructions of Boeing Service
Bulletin 737-78-1063, Revision 2, dated October 7, 1999.
(2) For airplanes equipped with engines identified in CFM CFM56-
7B Service Bulletin 73-0135, dated March 30, 2007: Install updated
full-authority digital electronic control (FADEC) software, in
accordance with the Accomplishment Instructions of CFM CFM56-7B
Service Bulletin 73-0135, dated March 30, 2007.
Inspection/Measurement
(i) At the applicable time specified in paragraph (j) of this
AD: Do the actions specified in paragraphs (i)(1), (i)(2), and
(i)(3) of this AD, in accordance with the Accomplishment
Instructions of Boeing Service Bulletin 737-78-1088, dated May 12,
2010. If any damage or discrepancy is found, before further flight,
do all applicable corrective actions, in accordance with
Accomplishment Instructions of Boeing Service Bulletin 737-78-1088,
dated May 12, 2010; except as required by paragraph (k) of this AD;
and except where the service bulletin refers to ``unsatisfactory''
findings, this AD assumes those parts or locations are
``unserviceable.''
(1) Do a detailed inspection for damage of the engine side and
inner wall side of the upper and lower insulation blankets.
(2) Measure the electrical conductivity on the aluminum upper
compression pads 2 and 3, as applicable.
(3) Inspect for discrepancies of the thrust reverser inner wall
(including an ultrasonic inspection for interplay delamination and
skin-to-core disbond, a detailed inspection for signs of heat damage
as applicable, and a detailed inspection for loose fasteners where
the inner wall attaches to the hinge beam and at the fasteners for
the compression pads).
Compliance Times for Paragraph (i)
(j) Do the actions specified in paragraph (i) of this AD at the
applicable time specified in paragraph (j)(1), (j)(2), (j)(3),
(j)(4), or (j)(5) of this AD.
(1) For airplanes with thrust reverser part number (P/N)
315A2295-003 through 315A2295-154 inclusive: Do the actions within
30 months after the effective date of this AD.
(2) For airplanes with thrust reverser P/N 315A2295-155 through
315A2295-174 inclusive: Do the actions within 60 months after the
effective date of this AD.
(3) For airplanes with thrust reverser P/N 315A2295-175 through
315A2295-190 inclusive: Do the actions within 72 months after the
effective date of this AD.
(4) For airplanes with thrust reverser P/N 315A2295-191 through
315A2295-198 inclusive: Do the actions within 84 months after the
effective date of this AD.
(5) For airplanes with thrust reverser P/N 315A2295-199 through
315A2295-202 inclusive: Do the actions within 96 months after the
effective date of this AD.
Exception to Boeing Service Bulletin 737-78-1088 Procedures
(k) Where Boeing Service Bulletin 737-78-1088, dated May 12,
2010, specifies to contact Boeing for appropriate action, repair
before further flight in accordance with a method approved by the
Manager, Seattle Aircraft Certification Office (ACO), FAA. 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.
Actions Concurrent With Paragraph (i)
(l) For airplanes identified in Boeing Service Bulletin 737-78-
1069, Revision 4, dated June 16, 2005: Before or concurrently with
the accomplishment of the requirements of paragraph (i) of this AD,
modify the thrust reverser inner wall and insulation blankets, in
accordance with the Accomplishment Instructions of Boeing Service
Bulletin 737-78-1069, Revision 4, dated June 16, 2005. A
modification done before the effective date of this AD is also
acceptable if done in accordance with Boeing Service Bulletin 737-
78-1069, Revision 1, dated June 13, 2002; Revision 2, dated February
6, 2003; or Revision 3, dated August 5, 2004.
(m) If the actions required by paragraph (i) of this AD are done
before the compliance time specified in paragraph (g) of this AD:
Before or concurrently with the accomplishment of the actions
required by paragraph (i) of this AD, the modification required by
paragraph (g) of this AD must be done.
Option to Requirements of Paragraphs (g) and (i)
(n) Accomplishment of all of the actions (including inspections
and modification) specified in Boeing Service Bulletin 737-78-1079,
Revision 2, dated June 7, 2010, within 24 months after the effective
date of this AD, is acceptable for compliance with the requirements
of paragraphs (g) and (i) of this AD and is acceptable for
compliance with the requirements of this AD, provided applicable
repairs are done before further flight, and provided the applicable
actions specified in paragraphs (h)(1), (h)(2), and (l) of this AD
have been done. Actions done before the effective date of this AD in
accordance with Boeing Service Bulletin 737-78-1079, dated August 6,
2007; or Revision 1, dated December 17, 2007; are also acceptable
for compliance with the corresponding actions specified in this
paragraph.
Alternative Methods of Compliance (AMOCs)
(o)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. Send information to
ATTN: Chris Parker, Aerospace Engineer, Propulsion Branch, ANM-140S,
FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue,
SW., Renton, Washington 98057-3356; telephone 425-917-6496; fax 425-
917-6590. Information may be e-mailed to: [email protected].
(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 principal maintenance inspector (PMI) or
principal avionics inspector (PAI), as appropriate, or lacking a
principal inspector, your local Flight Standards District Office.
The AMOC approval letter must specifically refer to this AD.
Issued in Renton, Washington on September 15, 2010.
Robert D. Breneman,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-24175 Filed 9-24-10; 8:45 am]
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