[Federal Register Volume 67, Number 65 (Thursday, April 4, 2002)]
[Proposed Rules]
[Pages 16064-16067]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-8111]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-367-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -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 supersedure of an existing 
airworthiness directive (AD), applicable to certain Boeing Model 737-
600, -700, and -800 series airplanes, that currently 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 action would limit 
the applicability of the existing requirements, clarify certain 
existing requirements, and require removal of the clamp shell installed 
previously and replacement of the existing quick-disconnect fuel supply 
hose, coupling, and strut fitting with new, fixed-B-nut-type parts. 
Such replacement would end the requirement for repetitive inspections. 
This action is necessary to prevent major fuel leakage due to excessive 
wear of the quick-disconnect coupling on the fuel hose, fire in the 
engine nacelle, and consequent loss of thrust from the affected engine, 
which could result in reduced controllability of the airplane. This 
action is intended to address the identified unsafe condition.

DATES: Comments must be received by May 20, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-367-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 ``Docket No. 2000-NM-367-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: Douglas Pegors, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 227-1446; 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:
     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.
     For each issue, state what specific change to the proposed 
AD is being requested.
     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 2000-NM-367-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. 2000-NM-367-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 28, 1999, the FAA issued AD 99-03-08, amendment 39-11022 
(64 FR 5590, February 4, 1999), applicable to certain Boeing Model 737-
600, -700, -700IGW, and -800 series airplanes, to require 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

[[Page 16065]]

shell on the coupling to prevent separation of the coupling halves. 
That action was 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 requirements of that 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.

Actions Since Issuance of Previous Rule

    In the preamble to AD 99-03-08, the FAA specified that the actions 
required by that AD were considered ``interim action'' and that the 
manufacturer was developing a modification to positively address the 
unsafe condition. The FAA indicated that it may consider further 
rulemaking action once the modification was developed, approved, and 
available. The manufacturer now has developed such a modification, and 
the FAA has determined that further rulemaking action is indeed 
necessary; this proposed AD follows from that determination.

Explanation of Relevant Service Information

    AD 99-03-08 refers to the original issue of Boeing Alert Service 
Bulletin 737-73A1011, dated November 25, 1998, as the appropriate 
source of service information for required actions. Subsequent to the 
issuance of AD 99-03-08, the FAA reviewed and approved Boeing Alert 
Service Bulletin 737-73A1011, Revision 1, dated April 15, 1999. That 
alert service bulletin divides the list of affected airplanes into 
Group I (those airplanes on which the clamp shell was not installed on 
the quick disconnect coupling during production) and Group II (those 
airplanes on which the clamp shell was installed on the quick 
disconnect coupling during production).
    The FAA now has reviewed and approved Boeing Alert Service Bulletin 
737-73A1011, Revision 2, dated July 13, 2000. In addition to procedures 
similar to those contained in the original issue (and Revision 1) of 
the alert service bulletin, Revision 2 of the alert service bulletin 
describes procedures for replacement of the existing quick-disconnect 
fuel supply hose, coupling, and strut fitting with new, fixed-B-nut-
type parts. The procedures include removing the clamp shell installed 
on the quick-disconnect coupling on the fuel hose per the requirements 
of the existing AD (for Group I airplanes) or during production (for 
Group II airplanes). This replacement eliminates the need for 
repetitive inspections for discrepancies of the quick-disconnect 
coupling on the fuel hose. Accomplishment of the actions specified in 
Revision 2 of the alert service bulletin is intended to adequately 
address the identified unsafe condition.
    The effectivity listing of Revision 2 of the alert service bulletin 
has also been revised to list only airplanes up to and including line 
number 560. Airplanes with line number 561 and subsequent have had the 
new fuel supply hose, coupling, and strut fitting installed during 
production.

Explanation of Change in Applicability

    AD 99-03-08 applies to Boeing Model 737-600, -700, -700IGW, and -
800 series airplanes. This proposed AD would apply to certain Boeing 
Model 737-600, -700, and -800 series airplanes, as listed in Revision 2 
of the alert service bulletin, described previously. We have determined 
that no model designated ``737-700IGW'' is listed on the type 
certificate for Model 737 series airplanes, and the reference to such a 
model in the existing AD was inadvertent. For the purposes of this AD, 
we consider such airplanes, which are in an increased-gross-weight 
configuration, to be Model 737-700 series airplanes; thus it is not 
necessary to refer to them separately. Note 1 of this proposed AD 
clarifies that these airplanes would be subject to this proposed AD.

Explanation of Other Changes to the Requirements of the Existing AD

    The FAA has clarified the inspection requirement contained in 
paragraph (a) of AD 99-03-08. Whereas that AD specifies a visual 
inspection, the FAA has revised paragraph (a) of this proposed AD to 
clarify that its intent is to require a general visual inspection. Note 
3 of this proposed AD defines that inspection.
    Paragraph (b) of AD 99-03-08 requires installation of a certain 
clamp shell on the quick-disconnect coupling on the fuel hose, and 
repetitive inspections to detect discrepancies of the quick-disconnect 
coupling. Because AD 99-03-08 applies to all Boeing Model 737-600, -
700, and -800 series airplanes, all of these airplanes are currently 
subject to the requirements of paragraph (b) of that AD. However, 
certain Model 737-600, -700, and -800 series airplanes were delivered 
with the clamp shell already installed. (As stated previously, these 
airplanes are identified as Group II in Revision 2 of the alert service 
bulletin.) Thus, only the repetitive inspections required by paragraph 
(b) of AD 99-03-08 are necessary for Group II airplanes. Therefore, to 
ease the administrative burden of this proposed AD for operators of the 
Group II airplanes, the FAA has revised paragraphs (a) and (b) of this 
proposed AD to apply only to Group 1 airplanes, as listed in Revision 2 
of the alert service bulletin. Further, for clarification, the 
repetitive inspections required by paragraph (b) of AD 99-03-08 have 
been moved to paragraph (c) of this proposed AD, and the corrective 
actions in paragraphs (b)(1) and (b)(2) of AD 99-03-08 have been 
redesignated as paragraphs (c)(1) and (c)(2) of this proposed AD. Also, 
a new Note 5 has been included in this proposed AD to clarify that the 
inspections in paragraph (c) of this AD are the same as those required 
by paragraph (b) of AD 99-03-08.
    Paragraph (b)(2) of AD 99-03-08 identifies Table 1. of the alert 
service bulletin as the appropriate source of service information for 
corrective actions if any discrepancy is found during the repetitive 
inspections. The FAA has determined that Figures 1 and 3 of the alert 
service bulletin are more comprehensive sources of service information 
for corrective actions if any discrepancy is found during the 
repetitive inspections following installation of the clamp shell kit. 
Therefore, for clarification, we have revised paragraph (c)(2) of this 
proposed AD (which, as discussed previously, was designated paragraph 
(b)(2) in AD 99-03-08) to refer to Figures 1 and 3 of the alert service 
bulletin, as applicable, as the appropriate sources of service 
information for necessary corrective action.

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 supersede AD 99-03-08 to continue to require 
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. The proposed AD would 
limit the applicability of the existing requirements, clarify certain 
existing requirements, and require accomplishment of the actions in 
Revision 2 of the alert service bulletin, described previously.

[[Page 16066]]

Cost Impact

    There are approximately 560 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 271 airplanes of U.S. registry 
would be affected by this proposed AD.
    The inspection that is currently required by AD 99-03-08 takes 
approximately 1 work hour per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the currently required inspection on U.S. operators is 
estimated to be $16,260, or $60 per airplane, per inspection cycle.
    For airplanes on which it has not already been accomplished during 
production, the installation of a clamp shell required by AD 99-03-08 
takes approximately 2 work hours per airplane to accomplish, at an 
average labor rate of $60 per work hour. Required parts are provided by 
the manufacturer at no cost to the operators. Based on these figures, 
the cost impact of the currently required installation is estimated to 
be $120 per airplane.
    The new replacement that is proposed in this AD action would take 
approximately 4 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts would be provided by 
the manufacturer at no cost to the operators. Based on these figures, 
the cost impact of the proposed replacement on U.S. operators is 
estimated to be $65,040, or $240 per airplane.
    The cost impact figures discussed above are 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.

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 removing amendment 39-11022 (64 FR 
5590, February 4, 1999), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 2000-NM-367-AD. Supersedes AD 99-03-08, Amendment 39-
11022.

    Applicability: Model 737-600, -700, and -800 series airplanes, 
listed in Group 1 or 2 of Boeing Alert Service Bulletin 737-73A1011, 
Revision 2, dated July 13, 2000; certificated in any category.

    Note 1: This AD applies to Model 737-700 series airplanes in an 
increased-gross-weight configuration, as listed in the service 
bulletin referred to in the applicability statement of this AD.


    Note 2: 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 (f)(1) 
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 major fuel leakage due to excessive wear of the 
quick-disconnect coupling on the fuel hose, fire in the engine 
nacelle, and consequent loss of thrust from the affected engine, 
which could result in reduced controllability of the airplane, 
accomplish the following:

Restatement of Requirements of AD 99-03-08

Repetitive Inspections and Corrective Actions

    (a) For airplanes listed in Group I of Boeing Alert Service 
Bulletin 737-73A1011, Revision 2, dated July 13, 2000: Within 7 days 
after February 19, 1999 (the effective date of AD 99-03-08, 
amendment 39-11022), perform a general 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; or Revision 2, dated July 13, 2000.
    (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.

Installation of Clamp Shell and Repetitive Inspections

    (b) For airplanes listed in Group I of Boeing Alert Service 
Bulletin 737-73A1011, Revision 2, dated July 13, 2000: Within 30 
days after February 19, 1999, 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; or Revision 2, dated July 13, 
2000. Accomplishment of such installation terminates the repetitive 
inspection requirements of paragraphs (a)(1) and (a)(2) of this AD.

New Requirements of This AD

    Note 3: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or drop-light, and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''


    Note 4: Accomplishment of the requirements of paragraphs (a), 
(b), and (c) of

[[Page 16067]]

this AD according to Boeing Alert Service Bulletin 737-73A1011, 
Revision 1, dated April 15, 1999, is acceptable for compliance with 
those paragraphs.

Repetitive Inspections

    (c) For airplanes listed in Groups I and II of Boeing Alert 
Service Bulletin 737-73A1011, Revision 2, dated July 13, 2000: 
Within 1,000 flight hours after installation of the clamp shell 
either per paragraph (b) of this AD (for Group I airplanes) or 
during production (for Group II airplanes), perform the inspection 
specified in paragraph (a) of this AD.

    Note 5: The repetitive inspections required by paragraph (c) of 
this AD were previously required by paragraph (b) of AD 99-03-08.

    (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 Figures 1 and 3 of the Accomplishment Instructions of the alert 
service bulletin, as applicable, and repeat the inspection 
thereafter at the time specified in TABLE 1. of the Accomplishment 
Instructions of the alert service bulletin.

Replacement of Existing Parts

    (d) For airplanes listed in Groups I and II of Boeing Alert 
Service Bulletin 737-73A1011, Revision 2, dated July 13, 2000: 
Within 3 years after the effective date of this AD, remove the clamp 
shell installed per paragraph (b) of this AD (for Group I airplanes) 
or during production (for Group II airplanes), and replace the 
existing quick-disconnect fuel hose, coupling, and strut fitting 
with new, fixed-B-nut-type parts, in accordance with Boeing Alert 
Service Bulletin 737-73A1011, Revision 2, dated July 13, 2000. Such 
replacement terminates the repetitive inspections required by 
paragraphs (a)(1), (a)(2), and (c) of this AD, as applicable.

Spares

    (e) After the effective date of this AD, no one may install a 
quick-disconnect fuel supply hose, coupling, or strut fitting with a 
part number listed in the ``Existing Part Number'' column of the 
table under paragraph 2.E. of Boeing Alert Service Bulletin 737-
73A1011, Revision 2, dated July 13, 2000, on any airplane.

Alternative Methods of Compliance

    (f)(1) 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.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 99-03-08, amendment 39-11022, are approved as 
alternative methods of compliance with paragraphs (a), (b), and (c) 
of this AD.

    Note 6: 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

    (g) Special flight permits may be issued in accordance with 
Secs. 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 March 28, 2002.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-8111 Filed 4-3-02; 8:45 am]
BILLING CODE 4910-13-P