[Federal Register Volume 64, Number 23 (Thursday, February 4, 1999)]
[Rules and Regulations]
[Pages 5590-5592]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-2495]
[[Page 5590]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-362-AD; Amendment 39-11022; AD 99-03-08]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-600, -700, -700IGW,
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 737-600, -700, -700IGW, and -800
series airplanes. This action requires repetitive inspections to detect
discrepancies of the quick-disconnect coupling on the fuel hose,
located at the fan case firewall; corrective action, if necessary; and
installation of a clamp shell on the coupling to prevent separation of
the coupling halves. This amendment is prompted by a report that a
quick-disconnect coupling on the fuel hose on an in-service airplane
was found loose and leaking fuel. The actions specified in this AD are
intended to detect and correct excessive wear of the quick-disconnect
coupling on the fuel hose, which could result in major fuel leakage,
fire in the engine nacelle, and consequent loss of thrust from the
affected engine.
DATES: Effective February 19, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of February 19, 1999.
Comments for inclusion in the Rules Docket must be received on or
before April 5, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-362-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: Bernie Gonzalez, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2682; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: The FAA has received a report indicating
that the quick-disconnect coupling on the fuel hose was found loose and
leaking fuel on an in-service Boeing Model 737-700 series airplane. As
a result of this report, Boeing requested that all operators perform
inspections to detect wear of the quick-disconnect coupling on the fuel
hose on both engines of all Boeing Model 737-600, -700, -700IGW, and -
800 series airplanes. During these inspections, an excessively worn
coupling was found on numerous airplanes, and several of these
discrepant couplings were leaking fuel. Wear of the coupling, which is
located at the fan case firewall of the engines, has been attributed to
resonance vibration from the engine-driven hydraulic pump.
Excessive wear of the quick-disconnect coupling on the fuel hose,
if not corrected, could initially cause leakage of a small amount of
fuel into the fan case fire zone of the engines. If such initial
leakage is not detected and corrected, the coupling could become
disconnected. Such disconnection could result in major fuel leakage,
fire in the engine nacelle, and consequent loss of thrust from the
affected engine.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
737-73A1011, dated November 25, 1998, which describes procedures for
repetitive visual inspections to detect discrepancies (i.e., fuel
leakage, wear of the lock teeth, and missing lock pins on the coupling
nut) of the quick-disconnect coupling on the fuel hose; and corrective
action, if necessary. If the coupling is found to be leaking,
corrective actions include tightening the coupling nut; or if the
coupling nut is tight, the lock teeth on the coupling are excessively
worn, or one or more lock pins are missing, corrective actions include
replacing the O-ring packing on the engine strut fuel fitting and
replacing the fuel hose assembly. The alert service bulletin also
describes procedures for installation of a clamp shell on the quick-
disconnect coupling to prevent separation of the coupling halves.
Accomplishment of the actions specified in the alert service bulletin
is intended to adequately address the identified unsafe condition.
Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design, this AD is
being issued to detect and correct excessive wear of the quick-
disconnect coupling on the fuel hose, located at the fan case firewall
of the engines; which could result in major fuel leakage, fire in the
engine nacelle, and consequent loss of thrust from the affected engine.
This AD requires accomplishment of the actions specified in the alert
service bulletin described previously, except as discussed below.
Differences Between This Rule and the Alert Service Bulletin
Operators should note that this AD requires, within 30 days, the
installation of the clamp shell described in the alert service
bulletin. Installation of the clamp shell is identified in the alert
service bulletin as an option that would allow the repetitive
inspection interval to be increased from 500 to 1,000 flight hours.
The FAA has determined that long-term continued operational safety
will be better assured by installation of a device to prevent
separation of the coupling halves and repetitive inspections at an
interval not to exceed 1,000 flight hours, rather than by
accomplishment of more frequent repetitive inspections (at intervals
not to exceed 500 flight hours). Inspections alone (i.e., without the
installation of the clamp shell) may not provide the degree of safety
assurance necessary for the transport airplane fleet.
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
availability of required parts, and the time necessary to perform the
installation (2 work hours). In light of all of these factors, the FAA
finds a compliance time of 30 days for accomplishing the installation
to be warranted, in that it represents an appropriate interval of time
allowable for affected airplanes to continue to operate without
compromising safety.
Interim Action
This is considered to be interim action. The manufacturer has
advised that it currently is developing a modification that will
positively address the unsafe condition addressed by this AD. Once this
modification is developed, approved, and available, the FAA may
consider additional rulemaking.
[[Page 5591]]
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 98-NM-362-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:
99-03-08 Boeing: Amendment 39-11022. Docket 98-NM-362-AD.
Applicability: Model 737-600, -700, -700IGW, and -800 series
airplanes; 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 detect and correct excessive wear of the quick-disconnect
coupling on the fuel hose, which could result in major fuel leakage,
fire in the engine nacelle, and consequent loss of thrust from the
affected engine, accomplish the following:
(a) Within 7 days after the effective date of this AD, perform a
visual inspection to detect discrepancies (i.e., fuel leakage, wear
of the lock teeth, or missing lock pins on the coupling nut) of the
quick-disconnect coupling on the fuel hose, located at the fan case
firewall, in accordance with Boeing Alert Service Bulletin 737-
73A1011, dated November 25, 1998.
(1) If no discrepancy is detected, repeat the inspection
thereafter at intervals not to exceed 500 flight hours, until the
installation required by paragraph (b) of this AD is accomplished.
(2) If any discrepancy is detected, prior to further flight,
perform follow-on corrective actions, as applicable, in accordance
with TABLE 1. of the Accomplishment Instructions of the alert
service bulletin, and repeat the inspection thereafter at the time
specified in TABLE 1. of the Accomplishment Instructions of the
alert service bulletin.
(b) Within 30 days after the effective date of this AD, install
an Aeroquip Clamp Shell, having part number (P/N) AE20074-165, on
the quick-disconnect coupling on the fuel hose, which is located at
the fan case firewall, in accordance with Boeing Alert Service
Bulletin 737-73A1011, dated November 25, 1998. Accomplishment of
such installation terminates the repetitive inspection requirements
of paragraph (a)(1) and (a)(2) of this AD. Within 1,000 flight hours
after installation of the clamp shell, repeat the inspection
specified in paragraph (a) of this AD.
(1) If no discrepancy is detected, repeat the inspection
thereafter at intervals not to exceed 1,000 flight hours.
(2) If any discrepancy is detected, prior to further flight,
perform follow-on corrective actions, as applicable, in accordance
with TABLE 1. of the Accomplishment Instructions of the alert
service bulletin, and repeat the inspection thereafter at the time
specified in TABLE 1. of the Accomplishment Instructions of the
alert service bulletin.
(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, 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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(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.
(e) The actions shall be done in accordance with Boeing Alert
Service Bulletin 737-73A1011, dated November 25, 1998. This
[[Page 5592]]
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.
(f) This amendment becomes effective on February 19, 1999.
Issued in Renton, Washington, on January 28, 1999.
Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-2495 Filed 2-3-99; 8:45 am]
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