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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] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration (FAA), DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM).

# 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 repetitive testing of the stabilizer takeoff warning switches, and corrective actions if necessary. This proposed AD results from 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 proposing 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:

We must receive comments on this proposed AD by October 29, 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                         *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 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:

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; telephone (425) 917-6472; 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-2010-0853; Directorate Identifier 2010-NM-116-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 received reports that the warning horn did not sound during the takeoff warning system test of the S132 “nose up stab takeoff warning switch.” Certain airplanes were found to have switch failures, which resulted in lack of aural warning when the stabilizer was positioned outside of the green band limits. Also, operators found that both internal contacts would not actuate during switch rotation. A takeoff warning system switch failure, if not corrected, could result in auto-rotation, resulting in tail strike, stall, high-speed runway overrun, rejected takeoff, or failure to clear terrain or obstacles after takeoff, which could reduce the ability of the flightcrew to maintain the safe flight and landing of the airplane. 

## Relevant Service Information 

We have reviewed Boeing Service Bulletin 737-27-1289, dated April 7, 2010, which describes procedures for repetitive testing of the stabilizer takeoff warning switches. The corrective actions include replacing failed stabilizer warning switches. 

## 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. 

## Costs of Compliance 

We estimate that this proposed AD would affect 963 airplanes of U.S. registry. We also estimate that it would take 1 work-hour per product to comply with this proposed AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $81,855, or $85 per product. 

## Authority for this Rulemaking 

                    Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I,                           ( print page 55692)                        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. 

§ 39.13 

2. The FAA amends § 39.13 by adding the following new AD:

**The Boeing Company:**                                 Docket No. FAA-2010-0853; Directorate Identifier 2010-NM-116-AD.                             

## Comments Due Date 

(a) We must receive comments by October 29, 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 737-27-1289, dated April 7, 2010. 

## Subject 

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

## Unsafe Condition 

(e) This AD results from 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 at intervals not to exceed 750 flight hours. 

## 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 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. Send information to                                 *Attn:*                                 Jeffrey W. Palmer, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle ACO, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 917-6472; fax (425) 917-6590. Information may be e-mailed to:                                 *9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.*

(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 reference this AD. 

Issued in Renton, Washington, on September 3, 2010. 

Jeffrey E. Duven, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2010-22847 Filed 9-13-10; 8:45 am] 

BILLING CODE 4910-13-P