[Federal Register Volume 68, Number 196 (Thursday, October 9, 2003)]
[Rules and Regulations]
[Pages 58268-58271]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-25491]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-326-AD; Amendment 39-13331; AD 2003-20-13]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-400, -500, -600, -700, 
and -800 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 737-400, -500, -600, -700, and -800 
series airplanes, that requires either modification of the wiring to 
the windshield wiper motors in the flight compartment or replacement of 
those windshield wiper motor/converters with new motor/converters. This 
action is necessary to prevent a reduction in flight crew visibility 
due to stalled wiper motors during heavy precipitation and a period of 
substantial crew workload, which could result in damage to the airplane 
structure and injury to flight crew, passengers, or ground personnel 
during final approach for landing. This action is intended to address 
the identified unsafe condition.

DATES: Effective November 13, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 13, 2003.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Don Eiford, Aerospace Engineer, Cabin 
Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 917-6465; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 737-400, -
500, -600, -700, and -800 series airplanes was published in the Federal 
Register on December 2, 2002 (67 FR 71500). That action proposed to 
require modification of the wiring to the windshield wiper motors in 
the flight compartment and nose wheel well areas. For certain 
airplanes, that action also provided for optional replacement of the 
windshield wiper motor/converters in the flight compartment.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Remove Prior/Concurrent Requirement for Optional Replacement

    The airplane manufacturer requests that the FAA remove the 
requirement specified in paragraph (b) of the proposed AD to accomplish 
the modification prior to or concurrently with the replacement. The 
airplane manufacturer states that the current production airplanes with 
the new wiper motor/converters, and the

[[Page 58269]]

equivalent service bulletins (discussed below), include the proposed 
wiring modification. It asserts that, if new wiper motor/converters are 
installed, accomplishing the airplane wiring modification prior to or 
concurrent with the wiper motor/converter replacement is redundant and 
does not add to the safety of the airplane. The airplane manufacturer 
also states that it will revise Boeing Service Bulletins 737-30-1054 
and 737-30-1055 to remove the recommendation to accomplish the airplane 
wiring modification prior to or concurrent with the wiper motor/
converter replacement.
    The FAA agrees. We find that replacement of the new wiper motor/
converters, without referencing the concurrent requirements of 
paragraph (a) of the proposed AD, will correct the root cause of the 
wiper motor stalls. Therefore, we have removed the requirement to 
accomplish the airplane wiring modification specified in paragraph (b) 
of this final rule (paragraph (a) of the proposed AD) prior to or 
concurrent with the replacement specified in paragraphs (c) and (d) of 
this final rule (paragraph (b) of the proposed AD).

Request To Mandate Optional Replacement

    One commenter requests that we mandate the proposed optional 
replacement of the windshield wiper motor/converters provided in 
paragraph (b) of the proposed AD, because the proposed wiring 
modification and wiper blade load reduction specified in paragraph (a) 
of the proposed AD would only make the flight crew's visibility worse 
due to wiper blade load reduction. This commenter also requested an 
extension of compliance time to allow adequate time to produce enough 
replacements. The other commenter, the airplane manufacturer, requests 
that we allow operators to accomplish either the modification or 
replacement.
    We partially agree with the commenters' requests. We do not agree 
that the optional replacement should be mandated. While we do agree 
that replacing the windshield wiper motor/converters is preferable to 
modifying the wiring to the windshield wiper motor, we have determined 
that the required modification will provide an acceptable level of 
safety for the affected airplanes. Therefore, we have changed this 
final rule to add a new paragraph (a), and re-lettered subsequent 
paragraphs accordingly, to clarify that operators have the option of 
accomplishing either the modification or replacement.
    Although we do not agree to mandate the replacement, we do agree 
that the compliance time of this final rule for accomplishing either 
the modification or replacement may be extended. The wiper motor/
converter manufacturer has confirmed that 36 months will allow it 
sufficient time to manufacture/refurbish motor/converters in the new 
configuration, provided operators order the motor/converters in a 
timely manner after the effective date of this final rule. We have 
determined that a compliance time of 36 months will not adversely 
affect safety and will ensure enough time for production of new motor/
converters and enable operators to comply using the preferred method. 
We have revised this final rule accordingly.

Request To Reference Additional Service Information

    Both commenters request that Boeing Service Bulletin 737-30-1055, 
Revision 1, dated March 6, 2003, which describes procedures for 
replacement of the wiper motor/converters for Model 737-400 and ``500 
series airplanes equipped with brushless windshield wiper motor/
converters, be added to the proposed AD for accomplishing the optional 
replacement for those airplanes. Both commenters further point out that 
this service bulletin was not included in the proposed AD.
    We agree. Since the issuance of the proposed AD, we have reviewed 
and approved Revision 1 of Boeing Service Bulletins 737-30-1054 and 
737-30-1055, both dated March 6, 2003, which describe procedures for 
the replacement of the wiper motor/converters. The proposed AD 
referenced the original issue of Boeing Service Bulletin 737-30-1054 as 
the appropriate source of service information for accomplishment of the 
replacement for Model 737-600, -700, and -800 series airplanes. The 
procedures specified in Revision 1 are essentially similar to those in 
the original issue of the service bulletins. We have changed this final 
rule to reference Revision 1 of those service bulletins as the 
appropriate sources of service information for the replacement. We have 
also added paragraph (d) to this final rule to add the replacement for 
Model 737-400 and -500 series airplanes, and added new paragraphs (e) 
and (f) to this final rule to give credit to operators for replacements 
accomplished before the effective date of this AD per the original 
issue of Boeing Service Bulletins 737-30-1054 and 737-30-1055. 
Replacement, accomplished after the effective date of this AD, shall be 
done in accordance with Boeing Service Bulletin 737-30-1055, Revision 
1, dated March 6, 2003.

Request To Remove References to Windshield Wiper Blade Flutter

    The airplane manufacturer also states that Boeing Service Bulletin 
737-30-1055 will be revised to state that it corrects the wiper 
stalling problem, not the wiper blade flutter as described in the 
original issue of Boeing Service Bulletin 737-30-1054. The airplane 
manufacturer asserts that the wiper blade flutter was a Boeing 
production issue, neither affecting safe operation of the system nor 
prevalent in the fleet.
    From this statement, we infer that the airplane manufacturer is 
requesting that we remove references to loss of wiper blade load 
leading to flutter of the wiper arm from the proposed AD. We agree and 
have revised this final rule accordingly.

Request To Clarify Description of Cause of Unsafe Condition

    The airplane manufacturer requests that we clarify the cause of the 
reported incidents stated in the Discussion section of the proposed AD. 
The airplane manufacturer explains that further investigation of the 
windshield wiper stalling problem revealed the root cause of the 
stalling to be inadequate backlash or clearance between the gears 
inside the wiper motor's converter, causing large internal losses due 
to friction between the gears, not the result of inadequate torque 
caused by insufficient electrical current as described in the proposed 
AD.
    In light of the results of the additional investigation described 
previously, we agree that the cause of the wiper motor/converter 
stalling could be more accurately described. However, the Discussion 
section is not repeated in a final rule, so no change to this final 
rule is necessary in this regard.

Request To Revise the Description of Location of the Modification

    The other commenter requests that we revise the proposed AD to 
exclude references to the ``nose wheel well areas.'' The commenter 
points out that Boeing Alert Service Bulletin 737-30A1052 does not 
specify a wiring modification in the those areas. We agree and have 
revised this final rule to remove references to the nose wheel well 
areas.

Request To Allow Designated Engineering Representative (DER) Approval

    The airplane manufacturer requests that certification of the new 
wiper motor/converter installed on airplanes without the wiring 
modification or production equivalent be accomplished by DER approval 
of revised Boeing

[[Page 58270]]

Service Bulletins 737-30-1054 and 737-30-1055.
    We do not agree. Because we have revised this final rule to allow 
operators to accomplish the replacement per Boeing Service Bulletins 
737-30-1054 and 737-30-1055, as applicable, as explained previously, 
there is no need for DER approval. No change to this final rule is 
necessary in this regard.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Changes to 14 CFR Part 39/Effect on the AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance. However, for clarity and consistency in this final rule, we 
have retained the language of the NPRM regarding that material.

Change to Labor Rate Estimate

    We have reviewed the figures we have used over the past several 
years to calculate AD costs to operators. To account for various 
inflationary costs in the airline industry, we find it necessary to 
increase the labor rate used in these calculations from $60 per work 
hour to $65 per work hour. The cost impact information, below, reflects 
this increase in the specified hourly labor rate.

Cost Impact

    There are approximately 483 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 162 Model 737-600, -700, and -
800 series airplanes of U.S. registry will be affected by this AD.
    The wiring modification, if accomplished in lieu of the wiper 
motor/converter replacement, will take approximately 15 work hours per 
airplane to accomplish, at an average labor rate of $65 per work hour. 
Required parts will be provided by the airplane manufacturer at no cost 
to operators. Based on these figures, the cost impact of the wiring 
modification required by this AD on U.S. operators is estimated to be 
$157,950, or $975 per airplane.
    The wiper motor/converter replacement, if accomplished in lieu of 
the wiring modification, will take approximately 3 work hours per 
airplane to accomplish, at an average labor rate of $65 per work hour. 
Parts cost will be minimal. Based on these figures, the cost impact of 
the replacement required by this AD is estimated to be $31,590, or $195 
per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.
    Currently, there are no affected Model 737-400 or -500 series 
airplanes on the U.S. Register. However, should an airplane be imported 
and placed on the U.S. Register in the future, the wiring modification, 
if accomplished in lieu of the wiper motor/converter replacement, will 
take approximately 20 work hours to accomplish, at an average labor 
rate of $65 per work hour. Required parts will be provided by the 
airplane manufacturer at no cost to operators. Based on these figures, 
the cost impact of the wiring modification will be $1,300 per airplane.
    Should an affected Model 737-400 or -500 series airplane be 
imported and placed on the U.S. Register in the future, wiper motor/
converter replacement, if accomplished in lieu of the wiring 
modification, will take approximately 4 work hours to accomplish the 
replacement of the wiper motor/converters, at an average labor rate of 
$65 per work hour. Parts cost will be minimal. Based on these figures, 
the cost impact of the replacement will be $260 per airplane.

Regulatory Impact

    The regulations adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness 
directive:

2003-20-13 Boeing: Amendment 39-13331. Docket 2001-NM-326-AD.

    Applicability: Model 737-400 and -500 series airplanes, as 
listed in Boeing Alert Service Bulletin 737-30A1052, dated October 
12, 2000; and Model 737-600, -700, and -800 series airplanes, as 
listed in Boeing Alert Service Bulletin 737-30A1049, dated June 1, 
2000; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (g) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a reduction in flight crew visibility due to stalled 
wiper motors during

[[Page 58271]]

heavy precipitation and a period of substantial crew workload, which 
could result in damage to the airplane structure and injury to 
flight crew, passengers, or ground personnel during final approach 
for landing; accomplish the following:

Compliance Time

    (a) For all airplanes: Within 36 months after the effective date 
of this AD, do the actions specified in paragraph (b) of this AD, or 
paragraph (c) or (d) of this AD, as applicable.

Modification

    (b) Modify the wiring to the left and right windshield wiper 
motors in the flight compartment (including changing certain wire 
bundles, reducing the windshield wiper blade force to between 3.5 
and 4.5 pounds, and doing an operational test of the windshield 
wiper system), per Boeing Alert Service Bulletin 737-30A1052, dated 
October 12, 2000 (for Model 737-400 and -500 series airplanes); or 
Boeing Alert Service Bulletin 737-30A1049, dated June 1, 2000 (for 
Model 737-600, -700, and -800 series airplanes); as applicable.

Replacement

    (c) For Model 737-600, -700, and -800 series airplanes: Replace 
the left and right windshield wiper motor/converters in the flight 
compartment (including increasing the blade force of the windshield 
wipers to between 6.5 and 7.5 pounds; and doing an operational test 
of the windshield wiper system), per Boeing Service Bulletin 737-30-
1054, Revision 1, dated March 6, 2003.
    (d) For Model 737-400 and -500 series airplanes equipped with 
brushless windshield wiper motor/converters: Replace the left and 
right windshield wiper motor/converters in the flight compartment 
(including increasing the blade force of the windshield wipers to 
between 6.5 and 7.5 pounds; and doing an operational test of the 
windshield wiper system), per Boeing Service Bulletin 737-30-1055, 
Revision 1, dated March 6, 2003.

Credit for Previously Accomplished Replacements

    (e) Replacement of the left and right windshield wiper motor/
converters accomplished prior to the effective date of this AD per 
Boeing Service Bulletin 737-30-1054, dated May 9, 2002, is 
considered acceptable for compliance with the requirements of 
paragraph (c) of this AD.
    (f) Replacement of the left and right windshield wiper motor/
converters accomplished prior to the effective date of this AD per 
Boeing Service Bulletin 737-30-1055, dated November 14, 2002, is 
considered acceptable for compliance with the requirements of 
paragraph (d) of this AD.

Alternative Methods of Compliance

    (g) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permit

    (h) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

Incorporation by Reference

    (i) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Boeing Alert Service Bulletin 737-30A1049, 
dated June 1, 2000; Boeing Alert Service Bulletin 737-30A1052, dated 
October 12, 2000; Boeing Service Bulletin 737-30-1054, Revision 1, 
dated March 6, 2003; or Boeing Service Bulletin 737-30-1055, 
Revision 1, dated March 6, 2003; as applicable. This incorporation 
by reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, 
Seattle, Washington 98124-2207. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (j) This amendment becomes effective on November 13, 2003.

    Issued in Renton, Washington, on October 2, 2003.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-25491 Filed 10-8-03; 8:45 am]
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