
[Federal Register Volume 77, Number 29 (Monday, February 13, 2012)]
[Rules and Regulations]
[Pages 7518-7520]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[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: 
me.boecom@boeing.com; 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 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: chris.r.parker@faa.gov.

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:
     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
     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: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (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: chris.r.parker@faa.gov.

(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: 
me.boecom@boeing.com; Internet https://www.myboeingfleet.com.
    (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 http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    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


