[Federal Register: December 2, 2002 (Volume 67, Number 231)]
[Proposed Rules]
[Page 71500-71502]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02de02-31]
-----------------------------------------------------------------------
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).
-----------------------------------------------------------------------
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:
9-anm-nprmcomment@faa.gov. 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