[Federal Register: October 9, 2003 (Volume 68, Number 196)]
[Rules and Regulations]
[Page 58268-58271]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09oc03-3]
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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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