[Federal Register Volume 67, Number 231 (Monday, December 2, 2002)]
[Proposed Rules]
[Pages 71500-71502]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-30348]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-326-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 737-400, -
500, -600, -700, and -800 series airplanes. This proposal would require 
modification of the wiring to the windshield wiper motors in the flight 
compartment and nose wheel well areas. For certain airplanes, this 
proposal also provides for optional replacement of the windshield wiper 
motor/converters in the flight compartment. 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: Comments must be received by January 16, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-326-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain

[[Page 71501]]

``Docket No. 2001-NM-326-AD'' in the subject line and need not be 
submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Don Eiford, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2788; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-326-AD.'' The postcard will be date stamped 
and returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2001-NM-326-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports of windshield motors stalling during 
flight on certain Boeing Model 737 series airplanes. In a number of 
incidents, the windshield wipers of both the pilot and first officer 
stalled. Stalling of the wiper motors was attributed to inadequate 
torque, caused by insufficient electrical current to the motor due to 
undersized wires to the windshield wiper motors. In addition, there 
have been reports of loss of windshield wiper blade load, which can 
lead to flutter of the windshield wiper arm and inability to clear the 
windshield. Such conditions could result in a reduction in flight crew 
visibility during heavy precipitation and a period of substantial crew 
workload, and consequent damage to the airplane structure and injury to 
flight crew, passengers, or ground personnel during final approach for 
landing.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Alert Service Bulletins 737-
30A1049, dated June 1, 2000 (for Model 737-600, -700, and -800 series 
airplanes); and 737-30A1052, dated October 12, 2000 (for Model 737-400 
and -500 series airplanes). The service bulletins describe procedures 
for modification of the wiring to the windshield wiper motor in the 
flight compartment and nose wheel well areas, as applicable. The 
modification specified in service bulletin 737-30A1049 includes 
changing wire bundles W0018, W2108, W2208, W2653, and W5506 in the 
flight compartment, and W2175 and W5506 above the nose wheel well area; 
reducing the blade force of the windshield wipers to between 3.5 and 
4.5 pounds; and doing an operational test of the windshield wiper 
system. The modification specified in Service Bulletin 737-30A1052 
includes changing wire bundles W0018, W0036, W0504, and W0544 in the 
flight compartment; reducing the blade force of the windshield wipers 
to between 3.5 and 4.5 pounds; and doing an operational test of the 
windshield wiper system.
    Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe condition.
    We also have reviewed and approved Boeing Service Bulletin 737-30-
1054, dated May 9, 2002 (for Model 737-600, -700, -700C, -800, and -900 
series airplanes). The service bulletin describes procedures for 
replacing the windshield wiper motor/converters in the flight 
compartment; 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. Replacement of the motor/converters will 
support an increase in blade load, which will eliminate the flutter of 
the windshield wiper arms. The service bulletin recommends prior or 
concurrent accomplishment of Service Bulletin 737-30A1049.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require modification of the wiring to the windshield 
wiper motors in the flight compartment and nose wheel well areas. For 
certain airplanes, this proposal also provides for optional replacement 
of the windshield wiper motor/converters in the flight compartment. The 
modification would be required to be accomplished in accordance with 
Service Bulletins 737-30A1049, and 737-30A1052, as applicable, except 
as discussed below.

Differences Between Proposed AD and Service Information

    The Boeing service bulletins listed below differ from the proposed 
AD in the compliance times specified for accomplishment of the proposed 
modification.
    [sbull] 737-30A1052 recommends that the modification of the wiring 
to the windshield wiper motors be done as soon as manpower and 
facilities are available.
    [sbull] 737-30A1049 recommends that the modification of the left-
side wiring be done within 90 days of receipt of the service bulletin, 
and the modification of the right-side wiring at the next 5,000-hour 
maintenance interval.
    We find that we must ensure that the necessary modification is 
completed in a timely manner. Therefore, this proposed AD would require 
modification of the windshield wiper motors within 18 months after the 
effective date of this AD.

[[Page 71502]]

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 would be affected by this 
proposed AD.
    It would take approximately 15 work hours per airplane to 
accomplish the proposed wiring modification, at an average labor rate 
of $60 per work hour. Required parts would be provided by the 
manufacturer at no cost to operators. Based on these figures, the cost 
impact of the modification proposed by this AD on U.S. operators is 
estimated to be $145,800, or $900 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this proposed 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.
    Should an operator elect to do the replacement of the wiper motor/
converters, it would take approximately 3 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Parts cost 
would be minimal. Based on these figures, the cost impact of the 
replacement proposed by this AD is estimated to be $180 per airplane.
    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, it would require 
approximately 20 work hours to accomplish the proposed modification, at 
an average labor rate of $60 per work hour. Required parts would be 
provided by the manufacturer at no cost to operators. Based on these 
figures, the cost impact of this proposed modification would be $1,200 
per airplane.

Regulatory Impact

    The regulations proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that 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) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (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

Sec.  39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Boeing: 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 (c) 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 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:

Modification

    (a) For all airplanes, within 18 months after the effective date 
of this AD: Modify the wiring to the left and right windshield wiper 
motors in the flight compartment and nose wheel well areas, as 
applicable (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.

Optional Replacement

    (b) 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, dated May 9, 2002. Paragraph (a) of this AD must be done prior 
to or concurrent with this paragraph. Replacement of the motor/
converters will support an increase in blade load, which will 
eliminate the flutter of the windshield wiper arms.

Alternative Methods of Compliance

    (c) 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

    (d) 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.

    Issued in Renton, Washington, on November 20, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-30348 Filed 11-29-02; 8:45 am]
BILLING CODE 4910-13-P