E8-27527. Airworthiness Directives; Boeing Model 737-400, -500, -600, -700, -700C, -800, and -900 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-400, -500, -600, -700, -700C, -800, and -900 series airplanes. This AD requires an inspection to determine the part and serial numbers of the windshield wiper motors for the pilot's and first officer's windshields, and doing applicable corrective actions. This AD results from two reports that the left and right windshield wipers stopped working in flight. We are issuing this AD to prevent failure of the windshield wipers in wet weather, which could result in decreased visibility for the flightcrew.

DATES:

This AD is effective December 30, 2008.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of December 30, 2008.

ADDRESSES:

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207; telephone [phone]; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com.

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 (telephone [phone]) is the 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:

Nick Wilson, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Airplane Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

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 certain Boeing Model 737-400, -500, -600, -700, -700C, -800, and -900 series airplanes. That NPRM was published in the Federal Register on February 8, 2008 (73 FR 7492). That NPRM proposed to require an inspection to determine the part and serial numbers of the windshield wiper motors for the pilot's and first officer's windshields, and the applicable corrective action.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received.

Request for Clarification of Certain Language

Boeing asks that the language in Note 1 of the NPRM, which specifies “determining the windshield wiper motor has been previously replaced,” be changed for clarification to “determining whether the power module replacement has been previously accomplished.” Boeing states that the list included as part of Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, provides information for determining whether the power module has been replaced with a properly soldered module.

We agree that the language in Note 1 of the AD should be clarified because the part description is different in Boeing Alert Service Bulletin 737-30A1059, dated September 10, 2007, and Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007 (referred to in the AD as the appropriate sources of service information for accomplishing the specified actions), and Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006 (referred to as an additional source of service information for determining the part and serial numbers of the windshield wiper motors). Boeing Alert Service Bulletin 737-30A1059, dated September 10, 2007, and Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007, specify replacing the windshield wiper motor, and Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, specifies replacing the power module of the windshield wiper motor. We disagree with using Boeing's suggested wording, which could result in confusion since the Boeing service bulletins specify replacing the motor instead of replacing the power module. We have changed Note 1 for clarification to include the description specified in Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006.

Request for Credit for Previously Accomplished Actions

Boeing also asks that we change paragraph (h) of the NPRM to include credit for Model 737-400 and -500 series airplanes on which the actions specified in Boeing Alert Service Bulletin 737-30A1059, dated September 10, 2007, were done before the effective date of the AD. Boeing states that Boeing Alert Service Bulletin 737-30A1059, dated September 10, 2007, provides instructions for corrective action for those airplanes.

We acknowledge and agree with Boeing's intent that credit should be given for actions done before the effective date of the AD. However, we do not agree to include credit for using the original issue of the service bulletin to do the actions specified in paragraph (h) of the AD. Boeing Alert Service Bulletin 737-30A1059, dated September 10, 2007, is already referred to in paragraph (f) of this AD as the appropriate source of service information for accomplishing the inspection and corrective actions for Model 737-400 and -500 series airplanes. Paragraph (e) of the AD specifies that compliance with the AD before the effective date (comply within the compliance times specified unless already done) meets the requirements of the AD. We have made no change to the AD in this regard.

Requests To Clarify Requirements for Maintenance Record Review and Re-Identifying the Wiper Motor Part Number

Southwest Airlines (SWA), KLM Fleet Services, and Airtran Airways request clarification of the review of airplane maintenance records and reidentification of the wiper motor part number, as specified in paragraph (f) of the NPRM.

SWA asks why the wiper motor must be re-identified while on the airplane since the review of airplane maintenance records is acceptable in lieu of an on-airplane inspection of the wiper motor part number and serial number. SWA also notes that the referenced service information requires operators to re-identify the part number of a wiper motor that has been determined to be in good and acceptable working condition. SWA states that re-identifying the part number would be more efficient and convenient if it could be done at the manufacturing facility during maintenance when the motor is removed for another reason.

KLM states that it is unclear if it is still mandatory to re-identify the wiper motor part number within the 60-month compliance time after reviewing the maintenance records, knowing that the wiper motor serial numbers are outside the affected modification range specified in Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006. KLM adds that intensive work is necessary if the wiper motor must be re-identified even if it is not affected.

AirTran reiterates the views of SWA and KLM and adds that units with replaced modules have eliminated the unsafe condition described in the NPRM. AirTran states that the wiper motors are located in a difficult location to view or access, and they cannot be re-identified while installed. AirTran notes that gaining access to the airplane, removing the wiper motor, re-identifying the motor, and re-installing the motor is an undue burden on the airlines, since the re-identification does not improve the safety of the airplane. AirTran suggests that the final rule specify that, for airplanes having a wiper motor module that has been replaced, as indicated in Appendix A of Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, the part number may be changed at the next shop visit, as opposed to changing the part number in service.

We agree with the commenters' concerns. Operators may review the maintenance records to comply with the AD during the 60-month compliance time proposed in the NPRM, as long as applicable corrective actions are also done in that time. In light of the comments provided, we have determined that, in this case, if the wiper motor is not affected by the requirements of the AD, re-identifying the wiper motor part number is not necessary to ensure an acceptable level of safety. Operators should not be required to remove and replace a part if it is deemed to be an acceptable part. We have added this clarification to paragraph (f) of this AD accordingly.

Request for Clarification of Wiper Motor Replacement Requirement

SWA asks that the wiper motor replacement be required only if the part number and serial number cannot be read or are listed in Appendix A of Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, with the “Module Completed” column marked as “No” (as specified in Steps 1.a. and 1.d., Section 3.B.—Work Instructions) of Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007.

We agree with SWA. The procedures specified in Steps 1.a. and 1.d. (and in Steps 2.a. and 2.d.) of the Work Instructions already specify replacement of the wiper motor if the part number and serial number cannot be read or are listed in Appendix A of Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, with the “Module Completed” column marked as “No”. The procedures in Steps 1.b. and 1.c. of the Work Instructions specify re-identification of the part if the part number and serial number are not listed in Appendix A or are listed in Appendix A of Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, with the “Module Completed” column marked as “Yes.” The replacement is required only if it meets the conditions specified in Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007, Steps 1.a. and 1.d. (or Steps 2.a. and 2.d.), of the Work Instructions. Therefore, we have made no change to the AD in this regard.

Request To Clarify Certain Part Numbers in Paragraphs (g) and (i) of the NPRM

Air Transport Association (ATA) on behalf of its member Delta Airlines states that the part numbers specified in paragraphs (g) and (i) of the NPRM have variations (P/N 2313M347-3 or P/N 2313M348-3), which should be noted in those paragraphs.

We agree with the commenters because the part numbers are the same, the variation is only in the dashes; therefore we have added those alternate part numbers to paragraphs (g) and (i) of this AD for clarification.

Request To Correct Typographical Error in Rosemount Service Bulletin

ATA on behalf of its member Delta Airlines states that Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, has a typographical error in Appendix A as follows: For Model Number 2313M-348-3, serial number (S/N) “M252” should be S/N “M0252.” Delta adds that this determination was made in cooperation with Rosemount.

Based on the information provided by the commenter, and confirmation from Rosemount Aerospace, we agree that the serial number specified in Appendix A of Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, is incorrect. We have added a new Note 2 to this AD to clarify the correct serial number as follows: For Model Number 2313M-348-3, S/N “M252” should be S/N “M0252.” We have been informed that Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, is being revised and the correct serial number will be included in the revision.

Request To Clarify Certain Requirements in Boeing Service Bulletin

ATA on behalf of its member Delta Airlines states that Boeing Service Bulletin 737-30A1057, dated October 6, 2006, referred to an incorrect airplane maintenance manual (AMM) section for the Windshield Wiper Motor System Operational Test. In addition, that service bulletin did not provide wiper motor condition information in the Work Instructions. That information was provided only in the Compliance section of Boeing Service Bulletin 737-30A1057, dated October 6, 2006.

We infer that the commenters are asking that paragraph (h) of the NPRM be revised to note these corrections; we agree with the commenters. There were mistakes in Boeing Service Bulletin 737-30A1057, dated October 6, 2006, which were corrected in Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007 (referred to in the AD as the appropriate source of service information for accomplishing the actions). The commenter states that it identified and incorporated the changes, which resulted in the issuance of Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007. The AMM section specified accomplishing the operational test in Boeing Alert Service Bulletin 737-30A1057, dated October 6, 2006, is AMM 30-42-21/501; the correct AMM section specified for accomplishing the operational test in Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007, is AMM 30-42-00/501. We have clarified paragraph (h) of this AD to refer to Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007, to ensure that the mistakes in the original issue of the service bulletin have been addressed.

Request To Extend Compliance Time

ATA on behalf of its member American Airlines (AAL) notes concern with the 60-month compliance time specified for accomplishing the actions specified in the NPRM. AAL states that its standard maintenance interval is 72 months; therefore, a 60-month compliance time could unnecessarily drive up out-of-service time and related costs. AAL recommends that we extend the compliance time to 72 months to align with industry standard material review board task intervals.

We do not agree to extend the compliance time. In developing an appropriate compliance time for this action, we considered the urgency associated with the subject unsafe condition, the availability of required parts, and the practical aspect of accomplishing the required actions within a period of time that corresponds to the normal scheduled maintenance for most affected operators. In light of these items, we have determined that a 60-month compliance time is appropriate. However, under the provisions of paragraph (j) of the AD, we will consider requests to adjust the compliance time if sufficient data are submitted to substantiate that the new compliance time would provide an acceptable level of safety. We have made no change to the AD in this regard.

Request To Allow an Alternative Method for Part Number Marking

SWA asks that another method of part marking be included in the NPRM. SWA asks why “classification RO” (Rubber Stamp Only per BAC5307) must be used to change the part number on the wiper motor. SWA asks that the NPRM allow another form of acceptable marking for the part number, such as permanent marker.

We agree that any permanent method of part marking is acceptable. We have added a new Note 3 to this AD to clarify that any permanent method is acceptable.

Request To Change Parts Installation Paragraph

WestJet asks that paragraph (i) of the NPRM (Parts Installation) be changed as follows: “As of the effective date of this AD, no person may install on any aircraft a Rosemount Aerospace windshield wiper motor having P/N 2313M-347-3 or P/N 2313M-348-3 that has a serial number that is listed in Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01.” WestJet states that windshield wiper motors having P/N 2313M-347-3 and P/N 2313M-348-3 with serial numbers outside of the affected modification range, that have not yet been “re-labeled” per Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, may be installed on any aircraft. WestJet adds that this change would allow operators to install a “mechanically serviceable” part (that has not yet been “re-labeled”) on an aircraft.

We do not agree to change paragraph (h) of the AD. Common industry practice is to control part configuration by part number, not by serial number. While we already agreed that it is not necessary to remove parts from the airplane just to revise the part numbers, we do not agree that it is acceptable to install the subject replacement parts without revising the part number. Ensuring that only parts with correct part numbers are installed on the airplane is an important part of maintaining configuration control and safe operation of the fleet. We have made no change to the AD in this regard.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD.

Costs of Compliance

We estimate that this AD affects 767 airplanes of U.S. registry. We also estimate that it takes about 1 work-hour per product to comply with the inspection. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $61,360 or $80 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, 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 airplane 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), 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
• Airplane
• 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

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

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

2008-24-05 Boeing: Amendment 39-15745. Docket No. FAA-2008-0152; Directorate Identifier 2007-NM-348-AD.

Effective Date

(a) This airworthiness directive (AD) is effective December 30, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to the Boeing airplanes identified in paragraphs (c)(1) and (c)(2) of this AD, certificated in any category.

(1) Model 737-400 and -500 series airplanes as identified in Boeing Alert Service Bulletin 737-30A1059, dated September 10, 2007.

(2) Model 737-600, -700, -700C, -800, and -900 series airplanes as identified in Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007.

Unsafe Condition

(d) This AD results from two reports that the left and right windshield wipers stopped working in flight. We are issuing this AD to prevent failure of the windshield wipers in wet weather, which could result in decreased visibility for the flightcrew.

Compliance

(e) Comply with this AD within the compliance times specified, unless already done.

Inspection and Corrective Actions if Necessary

(f) Except as provided by paragraph (g) of this AD: Within 60 months after the effective date of this AD, inspect to determine the part number and serial number of the windshield wiper motors for the pilot's and first officer's windshields, and do all applicable corrective actions, by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 737-30A1059, dated September 10, 2007 (for Model 737-400 and -500 series airplanes); or Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007 (for Model 737-600, -700, -700C, -800, and -900 series airplanes); as applicable. A review of airplane maintenance records is acceptable in lieu of the inspection required by paragraph (f) of this AD if the part number and serial number of the windshield wiper motors can be conclusively determined from that review. Following the inspection or records review, as applicable, for any windshield wiper motor that is found not to be affected by the requirements of this AD, re-identifying the part number is not required.

Note 1:

Boeing Alert Service Bulletin 737-30A1059, dated September 10, 2007; and Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007; refer to Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, as an additional source of service information for determining whether the windshield wiper motor (identified in the Rosemount service bulletin as the “power module”) has been previously replaced and for changing the part number.

Note 2:

Appendix A of Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, identifies an incorrect serial number for Model Number 2313M-348-3. Serial number M252” should be M0252.

Note 3:

Rosemount Aerospace Service Bulletin 2313M-347/2313M-348-30-01, dated June 30, 2006, specifies marking affected parts with an approved opaque material per BAC5307, classification RO, with an approved permanent marking material; however, for the purposes of this AD, any permanent method of part marking is acceptable.

Credit for Modification Done According to AD 2003-20-13

(g) For Model 737-400, -500, -600, -700, and -800 series airplanes: Accomplishing the modification required by paragraph (b) of AD 2003-20-13, amendment 39-13331, is acceptable for compliance with the requirements of paragraph (f) of this AD, provided that no Rosemount Aerospace windshield wiper motor having P/N 2313M-347-3 or P/N 2313M-348-3 (P/N 2313M347-3 or P/N 2313M348-3) has been installed.

Credit for Actions Done According to Previous Issue of Service Bulletin

(h) For Model 737-600, -700, -700C, -800, and -900 series airplanes: Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 737-30A1057, dated October 6, 2006, are acceptable for compliance with the requirements of paragraph (f) of this AD; provided that the wiper motor serial number was legible for inspection purposes and the operational test specified in Step 3 in Work Packages 2 and 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007, was completed.

Parts Installation

(i) As of the effective date of this AD, no person may install Rosemount Aerospace windshield wiper motors having P/N 2313M-347-3 or P/N 2313M-348-3 (P/N 2313M347-3 or P/N 2313M348-3) on any airplane.

Alternative Methods of Compliance (AMOCs)

(j)(1) The Manager, Seattle Airplane Certification Office, FAA, ATTN: Nick Wilson, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]; has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

(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 appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

Material Incorporated by Reference

(k) You must use Boeing Alert Service Bulletin 737-30A1059, dated September 10, 2007; or Boeing Service Bulletin 737-30A1057, Revision 1, dated October 31, 2007, 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 this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207; telephone [phone]; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com.

(3) You may review copies of the service information incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, 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 November 10, 2008.

Ali Bahrami,

Manager, Transport Airplane Directorate, Airplane Certification Service.