AD 2012-02-14
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 737-600 Series | Airworthiness Directives; The Boeing Company Airplanes |
| aircraft | The Boeing Company | 737-700 Series | Airworthiness Directives; The Boeing Company Airplanes |
| aircraft | The Boeing Company | 737-700C Series | Airworthiness Directives; The Boeing Company Airplanes |
| aircraft | The Boeing Company | 737-800 Series | Airworthiness Directives; The Boeing Company Airplanes |
| aircraft | The Boeing Company | 737-900 Series | Airworthiness Directives; The Boeing Company Airplanes |
| aircraft | The Boeing Company | 737-900ER Series | Airworthiness Directives; The Boeing Company Airplanes |
Unsafe Condition
The top 3 inches of the aero/fire seals of the blocker doors on the thrust reverser torque boxes are not fireproof.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the aero/fire seals of the blocker doors on the thrust reverser torque boxes to determine their part numbers. Replace affected aero/fire seals with new, improved aero/fire seals.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 60 months or 8,200 flight cycles, whichever occurs first, after the effective date of this AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, certificated in any category.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD was prompted by a report that the top 3 inches of the aero/fire seals of the blocker doors on the thrust reverser torque boxes are not fireproof. This AD requires a one-time inspection to determine the part numbers of the aero/fire seals of the blocker doors on the thrust reverser torque boxes on the engines, and replacing affected aero/fire seals with new, improved aero/fire seals. We are issuing this AD to prevent a fire in the fan compartment (a fire zone) from migrating through the seal to a flammable fluid in the thrust reverser actuator compartment (a flammable fluid leakage zone), which could result in an uncontrolled fire.
Applicability Source Text
Show captured applicability text from the source AD
(c) Applicability
This AD applies to all The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any
category.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 77, Number 29 (Monday, February 13, 2012)]
[Rules and Regulations]
[Pages 7518-7520]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2012-2679]
=======================================================================
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2006-25001; Directorate Identifier 2006-NM-079-AD;
Amendment 39-16937; AD 2012-02-14]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: We are adopting a new airworthiness directive (AD) for all The
Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER
series airplanes. This AD was prompted by a report that the top 3
inches of the aero/fire seals of the blocker doors on the thrust
reverser torque boxes are not fireproof. This AD requires a one-time
inspection to determine the part numbers of the aero/fire seals of the
blocker doors on the thrust reverser torque boxes on the engines, and
replacing affected aero/fire seals with new, improved aero/fire seals.
We are issuing this AD to prevent a fire in the fan compartment (a fire
zone) from migrating through the seal to a flammable fluid in the
thrust reverser actuator compartment (a flammable fluid leakage zone),
which could result in an uncontrolled fire.
DATES: This AD is effective March 19, 2012.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in the AD as of March 19,
2012.
ADDRESSES: For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management,
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-
[[Page 7519]]
2207; telephone 206-544-5000, extension 1; fax 206-766-5680; email:
<a href="/cdn-cgi/l/email-protection#7419115a161b11171b1934161b111d1a135a171b19"><span class="__cf_email__" data-cfemail="7b161e5519141e1814163b19141e12151c55181416">[email protected]</span></a>; Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>. 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 <a href="http://www.regulations.gov">http://www.regulations.gov</a>; 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 AD, the regulatory evaluation,
any comments received, and other information. The address for the
Docket Office (phone: 800-647-5527) is Document Management Facility,
U.S. Department of Transportation, Docket Operations, M-30, West
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE.,
Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Chris Parker, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone:
425-917-6496; fax: 425-917-6590; email: <a href="/cdn-cgi/l/email-protection#23404b514a500d510d534251484651634542420d444c55"><span class="__cf_email__" data-cfemail="4b28233922386539653b2a39202e390b2d2a2a652c243d">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Discussion
We issued a third supplemental notice of proposed rulemaking to
amend 14 CFR part 39 to include an airworthiness directive (AD) that
would apply to the specified products. That third supplemental NPRM was
published in the Federal Register on October 11, 2011 (76 FR 62649).
The original NPRM (71 FR 34025, June 13, 2006) proposed to require
replacing the aero/fire seals of the blocker doors on the thrust
reverser torque boxes on the engines with new improved aero/fire seals.
The first supplemental NPRM (73 FR 51382, September 3, 2008) proposed
to add airplanes to the applicability. The second supplemental NPRM (74
FR 34518, July 16, 2009) proposed to change the compliance time for the
replacement of the aero/fire seals. The third supplemental NPRM (76 FR
62649, October 11, 2011) proposed to additionally prohibit the
installation of certain non-fireproof thrust reverser seals.
Comments
We gave the public the opportunity to participate in developing
this AD. We have considered the comments received. The Boeing Company
and American Airlines both support the third supplemental NPRM (76 FR
62649, October 11, 2011).
Conclusion
We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
the AD as proposed except for minor editorial changes. We have
determined that these minor changes:
<bullet> Are consistent with the intent that was proposed in the
third supplemental NPRM (76 FR 62649, October 11, 2011), for correcting
the unsafe condition; and
<bullet> Do not add any additional burden upon the public than was
already proposed in the third supplemental NPRM (76 FR 62649, October
11, 2011).
Costs of Compliance
We estimate that this AD affects 803 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
Inspection for part number..... 1 work-hour x $85 None.................. $85 per $68,255 per
per hour = $85 inspection cycle. inspection
per inspection cycle.
cycle.
----------------------------------------------------------------------------------------------------------------
We estimate the following costs to do any necessary replacements
that would be required based on the results of the inspection. We have
no way of determining the number of aircraft that might need this
replacement:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product
----------------------------------------------------------------------------------------------------------------
Replacement............................. 5 work-hours x $85 per hour = $4,770 $5,195
$425.
----------------------------------------------------------------------------------------------------------------
According to the manufacturer, some of the costs of this AD may be
covered under warranty, thereby reducing the cost impact on affected
individuals. We do not control warranty coverage for affected
individuals. As a result, we have included all costs in our cost
estimate.
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
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 this AD:
[[Page 7520]]
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
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 FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):
2012-02-14 The Boeing Company: Amendment 39-16937; Docket No. FAA-
2006-25001; Directorate Identifier 2006-NM-079-AD.
(a) Effective Date
This AD is effective March 19, 2012.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any
category.
(d) Subject
Joint Aircraft System Component (JASC)/Air Transport Association
(ATA) of America Code 78, Engine exhaust.
(e) Unsafe Condition
This AD was prompted by a report that the top 3 inches of the
aero/fire seals of the blocker doors on the thrust reverser torque
boxes are not fireproof. We are issuing this AD to prevent a fire in
the fan compartment (a fire zone) from migrating through the seal to
a flammable fluid in the thrust reverser actuator compartment (a
flammable fluid leakage zone), which could result in an uncontrolled
fire.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Inspection To Determine Type of Aero/Fire Seals
For airplanes having an original airworthiness certificate
issued before the effective date of this AD, and for airplanes on
which the date of issuance of the original export certificate of
airworthiness is before the effective date of this AD: Within 60
months or 8,200 flight cycles, whichever occurs first, after the
effective date of this AD, perform a one-time detailed inspection to
determine the color of the aero/fire seals of the blocker doors on
the thrust reverser torque boxes on the engines. For any aero/fire
seal having a completely grey color (which is the color of seals
with part number (P/N) 315A2245-1 or 315A2245-2), with no red at the
upper end of the seal, do the actions specified in paragraph (i) of
this AD. For any aero/fire seal having a red color at the upper end
of the seal (which indicates installation of seals with P/N
315A2245-7 or 315A2245-8), no further action is required by this AD.
A review of airplane maintenance records is acceptable in lieu of
this inspection if from that review the part number of the correct
aero/fire seals (P/N 315A2245-7 or 315A2245-8) can be conclusively
determined to be installed.
(h) Definition
For the purposes of this AD, a detailed inspection is: ``An
intensive examination of a specific item, installation, or assembly
to detect damage, failure, or irregularity. Available lighting is
normally supplemented with a direct source of good lighting at an
intensity deemed appropriate. Inspection aids such as mirrors,
magnifying lenses, etc., may be necessary. Surface cleaning and
elaborate procedures may be required.''
(i) Replacement of the Aero/Fire Seals
For any aero/fire seal identified during the inspection/records
check required by paragraph (g) of this AD to have a non-fireproof
seal: Within six months after doing the actions required by
paragraph (g) of this AD, replace the aero/fire seals of the blocker
doors on the thrust reverser torque boxes on the engines with new,
improved aero/fire seals, in accordance with the Accomplishment
Instructions of Boeing Special Attention Service Bulletin 737-78-
1074, Revision 1, dated September 15, 2005. Replacing the aero/fire
seals of the blocker doors on the thrust reverser torque boxes on
the engines with new, improved aero/fire seals, in accordance with
the Accomplishment Instructions of Boeing Special Attention Service
Bulletin 737-78-1074, Revision 1, dated September 15, 2005, is
terminating action for the inspection required by paragraph (g) of
this AD.
(j) Parts Installation
As of the effective date of this AD, no person may install a
non-fireproof thrust reverser seal having P/N 315A2245-1 or P/N
315A2245-2 on any airplane.
(k) Credit for Actions Accomplished in Accordance With Previous Service
Information
Replacements done before the effective date of this AD in
accordance with the Accomplishment Instructions of Boeing Special
Attention Service Bulletin 737-78-1074, dated April 7, 2005, are
acceptable for compliance with the requirements of paragraph (i) of
this AD.
(l) Alternative Methods of Compliance (AMOCs)
(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. In accordance with 14
CFR 39.19, send your request to your principal inspector or local
Flight Standards District Office, as appropriate. If sending
information directly to the manager of the ACO, send it to the
attention of the person identified in the Related Information
section of this AD. Information may be emailed to: <a href="/cdn-cgi/l/email-protection#1c25315d5251314f797d68687079315d5f53315d51535f314e796d69796f686f5c7a7d7d327b736a"><span class="__cf_email__" data-cfemail="6b52462a252646380e0a1f1f070e462a2824462a26242846390e1a1e0e181f182b0d0a0a450c041d">[email protected]</span></a>.
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
(m) Related Information
For more information about this AD, contact Chris Parker,
Aerospace Engineer, Propulsion Branch, ANM-140S, 1601 Lind Avenue
SW., Renton, Washington 98057-3356; phone: 425-917-6496; fax: 425-
917-6590; email: <a href="/cdn-cgi/l/email-protection#fd9e958f948ed38fd38d9c8f96988fbd9b9c9cd39a928b"><span class="__cf_email__" data-cfemail="fb9893899288d589d58b9a89909e89bb9d9a9ad59c948d">[email protected]</span></a>.
(n) Material Incorporated by Reference
(1) You must use the following service information to do the
actions required by this AD, unless the AD specifies otherwise. The
Director of the Federal Register approved the incorporation by
reference (IBR) under 5 U.S.C. 552(a) and 1 CFR part 51.
(i) Boeing Special Attention Service Bulletin 737-78-1074,
Revision 1, dated September 15, 2005.
(2) For service information identified in this 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; email:
<a href="/cdn-cgi/l/email-protection#b4d9d19ad6dbd1d7dbd9f4d6dbd1dddad39ad7dbd9"><span class="__cf_email__" data-cfemail="ff929ad19d909a9c9092bf9d909a969198d19c9092">[email protected]</span></a>; Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
(3) You may review copies of the 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.
(4) You may also review copies of the service information that
is incorporated by reference at the National Archives and Records
Administration (NARA). For information on the availability of this
material at an NARA facility, call 202-741-6030, or go to <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.
Issued in Renton, Washington, on January 12, 2012.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2012-2679 Filed 2-10-12; 8:45 am]
BILLING CODE 4910-13-P
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Retrieved: Apr 6, 2026
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