[Federal Register Volume 65, Number 10 (Friday, January 14, 2000)]
[Rules and Regulations]
[Pages 2285-2287]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-876]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-342-AD; Amendment 39-11480; AD 99-26-21]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-300, -400, -500, -600, 
-700, and -800 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 737-300, -400, -500, -600, -700, 
and -800 series airplanes. This action requires a one-time detailed 
visual inspection of certain wire bundles and hydraulic hoses for the 
electric motor driven pump (EMDP) for hydraulic system ``B'' located in 
the right main wheel well to detect discrepancies; and corrective 
actions, if necessary. This amendment is prompted by a report that the 
wire bundle to the EMDP had been chafed by the pressure hose for 
hydraulic system ``B'' on a Model 737-700 series airplane, and reports 
of failed or damaged case drain or pressure hoses on the EMDP for 
hydraulic system ``B'' on Model 737-400 series airplanes. The actions 
specified in this AD are intended to prevent electrical arcing due to 
chafing between certain hydraulic hoses and adjacent wire bundles, 
which could result in a consequent increased risk of fire.

DATES: Effective January 31, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 31, 2000.
    Comments for inclusion in the Rules Docket must be received on or 
before March 14, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-342-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    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 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.

FOR FURTHER INFORMATION CONTACT: Stephen S. Oshiro, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; telephone (425) 227-2793; fax (425) 
227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received one report from an 
operator of a Boeing Model 737-700 series airplane describing how one 
of the three electrical wires in the wire bundle to the electric motor 
driven pump (EMDP) had chafed the pressure hose for hydraulic system 
``B.'' The FAA also has received several reports of failed or damaged 
case drain or pressure hoses on the EMDP for hydraulic system ``B'' for 
Boeing Model 737-300, -400, and -500 series airplanes. Chafing between 
the hydraulic case drain and pressure hoses could damage the hoses, and 
cause a hydraulic leak and failure of the pressure hose. Chafing 
between the wire bundle and hydraulic hoses could damage those 
components, and lead to electrical arcing between the components and a 
consequent hydraulic leak, which could result in an increased risk of 
fire.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-29A1076, Revision 1 (for Model 737-300, -400, and -500 series 
airplanes), and Boeing Alert Service Bulletin 737-29A1077, Revision 1 
(for Model 737-600, -700, and -800 series airplanes); both dated 
October 21, 1999; which describe procedures for an inspection of wire 
bundles W0334 and W5230, and the hydraulic case drain and pressure 
hoses for the EMDP for hydraulic system ``B'' to detect any 
discrepancies; and corrective actions, if necessary. Corrective actions 
include repair of the wire bundles if any damage is found; replacement 
of any hose that is damaged outside specified limits, and any 
incorrectly sized or loose components; and certain modifications. 
Modifications include adjusting or changing certain support clamps, 
fittings, and check valves; and installing additional clamps and 
spacers in the hydraulic hoses to obtain specified separation between 
the wire bundle and the hoses. For certain EMDP's, modifications also 
include ensuring that certain components are attached correctly.
    The alert service bulletins also specify a test of the EMDP if wire 
bundles W0334 or W5230 were repaired, or a leak test if the hydraulic 
case drain or pressure hoses were replaced in accordance with either 
Part 1 or Part 2 of the Accomplishment Instructions of the Boeing alert 
service bulletins, as applicable.

Explanation of Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Boeing Model 737-300, -400, -500, -600, -700, 
and -800 series airplanes of the same type design, this AD is being 
issued to prevent electrical arcing due to chafing between certain 
hydraulic hoses and adjacent wire bundles, which could result in a 
consequent increased risk of fire. This AD requires a one-time detailed 
visual inspection of wire bundles W0334 and W5230 and the hydraulic 
case drain and pressure hoses for the EMDP for hydraulic system ``B'' 
located in the right main wheel well to detect discrepancies; and 
corrective actions, if necessary. The actions are required to be 
accomplished in accordance with the alert service bulletins described 
previously, except as described below.

[[Page 2286]]

Differences Between This AD and the Alert Service Bulletins

    Operators should note that the alert service bulletins recommend 
accomplishment of the inspection and corrective actions as soon as 
manpower and equipment are available. However, the FAA has determined 
that the compliance time proposed by the manufacturer would not address 
the identified unsafe condition in a timely manner. In developing an 
appropriate compliance time for this AD, the FAA considered not only 
the manufacturer's recommendation, but the degree of urgency associated 
with addressing the subject unsafe condition, the average utilization 
of the affected fleet, and the time necessary to perform the inspection 
(less than two hours). In light of all these factors, the FAA finds a 
90-day compliance time for accomplishing the required actions to be 
warranted, in that it represents an appropriate interval of time 
allowable for affected airplanes to continue to operate without 
compromising safety.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-342-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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

    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

    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:

99-26-21  Boeing: Amendment 39-11480. Docket 99-NM-342-AD.

    Applicability: Model 737-300, -400, and -500 series airplanes, 
as listed in Boeing Alert Service Bulletin 737-29A1076, Revision 1, 
dated October 21, 1999; and Model 737-600, -700, and -800 series 
airplanes, as listed in Boeing Alert Service Bulletin 737-29A1077, 
Revision 1, dated October 21, 1999; 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 (e) 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 electrical arcing due to chafing between certain 
hydraulic hoses and adjacent wire bundles, which could result in a 
consequent increased risk of fire; accomplish the following:

Actions for Model 737-300, -400, and -500 Series Airplanes

    (a) For certain Model 737-300, -400, and -500 series airplanes 
on which the actions specified by Boeing Alert Service Bulletin 737-
29A1076, dated April 2, 1998, have not been accomplished: Within 90 
days after the effective date of this AD, perform a one-time 
detailed visual inspection of wire bundle W0334 and the hydraulic 
case drain and pressure hoses for the electric motor driven pump 
(EMDP) for hydraulic system ``B'' to detect any discrepancy (e.g., 
damage or chafing of wire bundle W0334 and the hydraulic case drain 
and pressure hoses, and incorrect separation between those 
components), in accordance with Part 1 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-29A1076, Revision 
1, dated October 21, 1999.
    (1) If no discrepancy is found, no further action is required by 
this paragraph.
    (2) If any discrepancy is found, prior to further flight, 
perform corrective actions in accordance with Part 1 of the 
Accomplishment Instructions of the alert service bulletin.

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at an

[[Page 2287]]

intensity deemed appropriate by the inspector. Inspection aids such 
as mirrors, magnifying lenses, etc. may be used. Surface cleaning 
and elaborate access procedures may be required.''

    (b) For certain Model 737-300, -400, and -500 series airplanes 
on which the actions specified by Boeing Alert Service Bulletin 737-
29A1076, dated April 2, 1998, have been accomplished: Within 90 days 
after the effective date of this AD, perform a one-time detailed 
visual inspection of wire bundle W0334 and the hydraulic case drain 
and pressure hoses for the EMDP for hydraulic system ``B'' to detect 
any discrepancy (e.g., damage or chafing of wire bundle W0334 and 
the hydraulic case drain and pressure hoses; and incorrect 
separation between those components), in accordance with Part 2 of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-29A1076, Revision 1, dated October 21, 1999.
    (1) If no discrepancy is found, no further action is required by 
this paragraph.
    (2) If any discrepancy is found, prior to further flight, 
perform corrective actions in accordance with Part 2 of the 
Accomplishment Instructions of the alert service bulletin.

Actions for Model 737-600, -700, and -800 Series Airplanes

    (c) For certain Model 737-600, -700, and -800 series airplanes 
on which the actions specified by Boeing Alert Service Bulletin 737-
29A1077, dated March 4, 1999, have not been accomplished: Within 90 
days after the effective date of this AD, perform a one-time 
detailed visual inspection of wire bundle W5230 and the hydraulic 
case drain and pressure hoses for the EMDP for hydraulic system 
``B'' to detect any discrepancy (e.g., damage or chafing of the 
W5230 wire bundle and the hydraulic case drain and pressure hoses; 
and incorrect separation between those components) in accordance 
with Part 1 of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-29A1077, Revision 1, dated October 21, 1999.
    (1) If no discrepancy is found, no further action is required by 
this paragraph.
    (2) If any discrepancy is found, prior to further flight, 
perform corrective actions in accordance with Part 1 of the 
Accomplishment Instructions of the alert service bulletin.
    (d) For certain Model 737-600, -700, and -800 series airplanes 
on which the actions specified by Boeing Alert Service Bulletin 737-
29A1077, dated March 4, 1999, have been accomplished: Within 90 days 
after the effective date of this AD, perform a one-time detailed 
visual inspection of wire bundle W5230 and the case drain and 
pressure hoses for the EMDP for hydraulic system ``B'' to detect any 
discrepancy (e.g., damage or chafing of the W5230 wire bundles and 
the hydraulic case drain and pressure hoses; and incorrect 
separation between those components), in accordance with Part 2 of 
Boeing Alert Service Bulletin 737-29A1077, Revision 1, dated October 
21, 1999.
    (1) If no discrepancy is found, no further action is required by 
this paragraph.
    (2) If any discrepancy is found, prior to further flight, 
perform corrective actions in accordance with Part 2 of the 
Accomplishment Instructions of the alert service bulletin.

Alternative Methods of Compliance

    (e) 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, Transport Airplane Directorate. 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (f) 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

    (g) The inspection and corrective actions shall be done in 
accordance with Boeing Alert Service Bulletin 737-29A1076, Revision 
1, dated October 21, 1999; or Boeing Alert Service Bulletin 737-
29A1077, Revision 1, dated October 21, 1999; 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.
    (h) This amendment becomes effective on January 31, 2000.

    Issued in Renton, Washington, on January 7, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-876 Filed 1-13-00; 8:45 am]
BILLING CODE 4910-13-U