Airworthiness Directives; The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER Series Airplanes

[Federal Register Volume 76, Number 117 (Friday, June 17, 2011)]
[Rules and Regulations]
[Pages 35327-35330]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-14344]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0853; Directorate Identifier 2010-NM-116-AD; 
Amendment 39-16720; AD 2011-12-13]
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: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD requires repetitive testing of the 
stabilizer takeoff warning switches, and corrective actions if 
necessary. This AD was prompted by reports that the warning horn did 
not sound during the takeoff warning system test of the S132 ``nose up 
stab takeoff warning switch.'' We are issuing this AD to detect and 
correct a takeoff warning system switch failure, which could reduce the 
ability of the flightcrew to maintain the safe flight and landing of 
the airplane.

DATES: This AD is effective July 22, 2011.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of July 22, 
2011.

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 98124-2207; 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 docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (phone: 800-647-5527) is

[[Page 35328]]

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: Jeffrey W. Palmer, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office (ACO), 1601 Lind Avenue, SW., Renton, Washington 
98057-3356; phone: 425-917-6472; fax: 425-917-6590; e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
the specified products. That NPRM published in the Federal Register on 
September 14, 2010 (75 FR 55691). That NPRM proposed to require 
repetitive testing of the stabilizer takeoff warning switches, and 
corrective actions if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
and the FAA's response to each comment.

Support for the NPRM

    Continental Airlines, Delta Air Lines, and the Air Line Pilots 
Association (ALPA), International, support the NPRM.

Requests To Revise Costs of Compliance Section of the NPRM

    American Airlines (AA) requested that we revise the Cost of 
Compliance section of the NPRM to show a more accurate cost to 
operators. Delta Air Lines noted that the actual cost to operators will 
be more than what is described in the Costs of Compliance section given 
in the NPRM.
    AA explained that the Costs of Compliance estimate provided in the 
NPRM specifies 1 work-hour per product at an average labor rate of $85 
per hour. However, AA stated that Boeing Service Bulletin 737-27-1289, 
dated April 7, 2010, estimates 4.25 hours to accomplish the test of the 
switches and an additional 2.25 hours each to replace the switches. AA 
asserted that Boeing Service Bulletin 737-27-1289, dated April 7, 2010, 
estimates a cost to operators of $361.25 to $743.75 per product.
    We agree to provide clarification of the Costs of Compliance 
section in this final rule. Since the issuance of the NPRM, Boeing has 
issued Service Bulletin Information Notice 737-27-1289 IN 02, dated 
September 27, 2010, which provides revised work-hours for testing (1 
work-hour) and the on-condition replacement (2 work-hours) of the 
switches. We have revised the Costs of Compliance section of this final 
rule to reflect the latest cost information provided by the 
manufacturer.

Request To Add Terminating Action for Repetitive Inspections

    ALPA requested that we revise the NPRM to include a terminating 
action for the repetitive inspections proposed by the NPRM. AA stated 
that the lack of a terminating action for the repetitive inspections 
proposed by the NPRM places pressure on the operator because it is 
required to continue the repetitive inspections at intervals of 750 
flight cycles for the affected airplanes.
    We disagree to include a terminating action in the final rule. The 
manufacturer has advised that extensive modifications would be required 
to eliminate the repetitive inspections. No terminating action is 
currently available. However, if a modification that addresses the 
unsafe condition addressed by this AD is developed, approved, and 
available, operators could request approval of an alternative method of 
compliance (AMOC) to this AD for doing that modification. No change has 
been made to the final rule in regard to this issue.

Request To Allow Repair of Switch Before Replacing

    AA questioned why operators could not attempt to repair a failed 
switch before being required to replace the failed switch. AA explained 
that the NPRM and Boeing Service Bulletin 737-27-1289, dated April 7, 
2010, require the switch to be replaced if it fails the test. AA 
reasoned that the switches are adjustable per ``AMM 31-51-02--
Stabilizer Takeoff Warning Switches--Adjustment/Test.''
    From these statements, we infer that AA is requesting that we 
revise the NPRM to allow operators to repair a failed switch. We 
disagree. The intent of the test specified in paragraph (g) of the 
final rule is to find and, if necessary, replace switches that fail to 
electrically open or close properly regardless of adjustment [within 
the switch's allowable range of adjustment], not switches that are 
simply out of adjustment. For switches that are out of adjustment, it 
is acceptable to attempt to adjust a switch that fails the test, prior 
to replacing the switch. However, the allowable range of adjustment is 
limited. If the switch continues to fail the test within the switch's 
allowable range of adjustment, it must be replaced. To preclude test 
failures due to an out-of-adjustment switch, the manufacturer 
recommends doing the test with stabilizer trim set at least one unit 
outside the green band. Doing the test according to the manufacturer's 
recommendation will ensure that any test failures are due to a 
malfunctioning switch, not due to a switch that is simply out of 
adjustment. No change has been made to the final rule in regard to this 
issue.

Request To Allow Additional Replacement Switch

    Delta Air Lines (the commenter) requested that we revise the NPRM 
to allow switch part number (P/N) 35EN27-4 to be an additional 
acceptable replacement switch for failed switches. The commenter 
explained that paragraph (h) of the NPRM specifies that a stabilizer 
takeoff warning switch which fails the required test must be replaced 
with a new switch prior to further flight, in accordance with Boeing 
Service Bulletin 737-27-1289, dated April 7, 2010. The commenter 
further explained that ``Section 3.B `Work Instructions' '' of this 
service information does not specify replacement switches by part 
number. The commenter also explained that replacement switch part 
numbers are found in ``Section 2.C.2 `Parts and Materials Supplied by 
the Operator' of the SB,'' and that this section lists only three part 
numbers. The commenter expressed that it is aware of an additional 
switch, which is not listed in Boeing Service Bulletin 737-27-1289, 
dated April 7, 2010.
    We do not agree to allow switch P/N 35EN27-4 to be an additional 
acceptable replacement switch. This part has not been validated as an 
acceptable replacement part at this time. The manufacturer is currently 
assessing the acceptability of this part as a replacement part and 
might revise the service information at a later time to include this 
part number. If this part number is found to be acceptable at a later 
date, its use might be approved as an AMOC to this AD. No change has 
been made to the final rule in regard to this issue.

Effect of This AD on AD 88-22-09

    Paragraph (b) (``Affected ADs'') of this AD has been revised to 
note that this AD affects AD 88-22-09, Amendment 39-6054 (Docket No. 
88-NM-132-AD; 53 FR 41313, October 21, 1988). In addition, we have 
revised paragraph (g) of this AD to state that accomplishment of the 
repetitive tests required by this

[[Page 35329]]

AD terminates the operational and functional checks of the takeoff 
configuration warning system required by paragraph A., required item 3 
(``Elevator out of Green Band switches'') of AD 88-22-09 for the 
airplanes affected by this new AD.

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.

Costs of Compliance

    We estimate that this AD would affect 963 airplanes of U.S. 
registry. We also estimate that it would take about 1 work-hour per 
product to comply with this AD. The average labor rate is $85 per work-
hour. Based on these figures, we estimate the cost of this AD to the 
U.S. operators to be $81,855, or $85 per product, per inspection cycle.
    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed inspection. 
We have no way of determining the number of aircraft that might need 
this replacement:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
2 work-hours x $85 per hour = $170............  Replacement.....................              $0            $170
----------------------------------------------------------------------------------------------------------------

    According to the manufacturer, some of the costs of this proposed 
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:
    (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):

2011-12-13 The Boeing Company: Amendment 39-16720; Docket No. FAA-
2010-0853; Directorate Identifier 2010-NM-116-AD.

Effective Date

    (a) This AD is effective July 22, 2011.

Affected ADs

    (b) This AD affects AD 88-22-09, Amendment 39-6054 (Docket No. 
88-NM-132-AD). This AD does not supersede the requirements of AD 88-
22-09.

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 737-27-1289, 
dated April 7, 2010.

Subject

    (d) Air Transport Association (ATA) of America Code 27: Flight 
Controls.

Unsafe Condition

    (e) This AD was prompted by reports that the warning horn did 
not sound during the takeoff warning system test of the S132 ``nose 
up stab takeoff warning switch.'' The Federal Aviation 
Administration is issuing this AD to detect and correct a takeoff 
warning system switch failure, which could reduce the ability of the 
flightcrew to maintain the safe flight and landing of the airplane.

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.

Test

    (g) Within 6 months after the effective date of this AD, test 
the stabilizer takeoff warning switches, in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 737-27-1289, 
dated April 7, 2010. Repeat the test thereafter at intervals not to 
exceed 750 flight hours. Accomplishment of the repetitive tests 
required by paragraph (g) of this AD terminates the operational and 
functional checks of the takeoff configuration warning system 
required by paragraph A., required item 3 (``Elevator out of Green 
Band switches'') of AD 88-22-09.

Replacement and Re-test

    (h) If any stabilizer takeoff warning switch fails the test 
required in paragraph (g) or (h) of this AD, replace the stabilizer 
takeoff warning switch with a new switch and test the new switch 
before further flight, in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 737-27-1289, dated April 7, 
2010. Within 750 flight hours after replacement of any switch, test 
the replaced switch, in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 737-27-1289, dated April 7, 
2010; and repeat this test on the replaced

[[Page 35330]]

switch thereafter at intervals not to exceed 750 flight hours.

Special Flight Permit

    (i) Special flight permits, as described in Section 21.197 and 
Section 21.199 of the Federal Aviation Regulations (14 CFR 21.197 
and 21.199), are not allowed.

Alternative Methods of Compliance (AMOCs)

    (j)(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 e-mailed to: [email protected].
    (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.

Related Information

    (k) For more information about this AD, contact Jeffrey W. 
Palmer, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, 
FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue, 
SW., Renton, Washington 98057-3356; phone: 425-917-6472; fax: 425-
917-6590; e-mail: [email protected].

Material Incorporated by Reference

    (l) You must use Boeing Service Bulletin 737-27-1289, dated 
April 7, 2010, to do the actions required by this AD, unless the AD 
specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of Boeing Service Bulletin 737-27-1289, 
dated April 7, 2010, under 5 U.S.C. 552(a) and 1 CFR part 51.
    (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; phone: 206-
544-5000, extension 1; fax: 206-766-5680; e-mail: 
[email protected]; 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 June 3, 2011.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-14344 Filed 6-16-11; 8:45 am]
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