[Federal Register Volume 62, Number 239 (Friday, December 12, 1997)]
[Rules and Regulations]
[Pages 65355-65357]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-32233]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-282-AD; Amendment 39-10239; AD 97-25-15]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 727 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 727 series airplanes. This action
requires repetitive inspections to detect cracking of the rear spar web
or fuel leakage of the wing center section, and repair, if necessary.
This amendment also provides for an optional modification of the rear
spar web that constitutes terminating action for the repetitive
inspections. This amendment is prompted by several reports of fuel
leakage due to cracking of the rear spar web of the wing center
section. The actions specified in this AD are intended to detect and
correct such cracking of the rear spar web, which could permit fuel
leakage into the airflow multiplier, and could result in an electrical
short that could cause a fire.
DATES: Effective December 29, 1997.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of December 29, 1997.
Comments for inclusion in the Rules Docket must be received on or
before February 10, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-282-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: Walter Sippel, Aerospace Engineer,
Airframe Branch, ANM-120S, Seattle Aircraft Certification Office, FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2774; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: The FAA has received reports indicating that
fuel leakage of the wing center section has occurred on several Boeing
Model 727 series airplanes due to cracking of the rear spar web of the
wing center section. The cracking initiates on the forward side of the
spar and propagates through the web at the upper machined land radius
between Left Body Buttock Line (BBL) 40 and Right BBL 40. In two
instances, cracking was reported on airplanes that had accumulated less
than 25,000 total flight cycles. In another case, fuel leakage resulted
in fuel odors being emitted into the cabin area. Investigation revealed
that fuel was leaking into the airflow multiplier. Fuel leakage into
the airflow multiplier due to cracking of the rear spar web of the wing
center section, if not detected and corrected, could result in an
electrical short that could cause a fire.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
727-57A0182, dated September 18, 1997. This alert service bulletin
describes procedures for removing the access panels of the wing center
section to perform repetitive visual inspections using a borescope, or
ultrasonic with high frequency eddy current inspections, to detect
cracking of the rear spar web or fuel leakage of the wing center
section, and repair, if necessary.
In addition, the alert service bulletin describes procedures for
modification of the rear spar web of the wing center section to prevent
cracking of the rear spar web, which eliminates the need for the
repetitive inspections the modification involves stop drilling any
[[Page 65356]]
cracking, and repairing the rear spar web.
The alert service bulletin references Boeing Drawing 65C37620 as an
additional source of service information for accomplishment of the
repair and modification.
Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other Boeing Model 727 series airplanes of the same
type design, this AD is being issued to detect and correct cracking of
the rear spar web, which could permit fuel leakage into the airflow
multiplier and resultant electrical shorting and fire. This AD requires
repetitive inspections [either visual inspections using a borescope or
a mirror, or ultrasonic and high frequency eddy current (HFEC)
inspections] to detect cracking of the rear spar web or fuel leakage of
the wing center section, and repair, if necessary. This AD also
provides for an optional modification of the rear spar web of the wing
center section, which constitutes terminating action for the repetitive
inspection requirements of this AD. The inspections, certain repairs,
and the modification are required to be accomplished in accordance with
the alert service bulletin described previously. Certain repairs are
required to be accomplished in accordance with a method approved by the
FAA.
Operators should note the following differences between this AD and
the Boeing alert service bulletin:
Although the alert service bulletin recommends an initial
inspection threshold of within 500 flight cycles for airplanes that
have accumulated between 15,000 and 25,000 total flight cycles, and an
initial inspection threshold of within 300 flight cycles for airplanes
that have accumulated 25,000 or more total flight cycles, this AD
specifies an initial compliance time of ``prior to the accumulation of
15,000 total flight cycles, or within 300 flight cycles after the
effective date of this AD, whichever occurs later.'' The FAA finds
that, in view of the reports of cracking of the rear spar web on two
airplanes that had accumulated less than 25,000 total flight cycles,
the initial compliance time specified in this AD is appropriate.
Further, the FAA finds that adequate justification for permitting an
inspection threshold of 500 flight cycles for airplanes that have
accumulated over 15,000 total flight cycles, but under 25,000 total
flight cycles, has not been presented. Therefore, an initial inspection
is required to be accomplished on all airplanes within 300 flight
cycles after the effective date of this AD.
This AD requires that, for any cracking or fuel leakage
detected that is outside the areas specified in the alert service
bulletin, repair must be accomplished in accordance with a method
approved by the FAA.
This AD requires that the access panel only be opened in
order to perform the inspections, rather than removed, as described in
the Boeing alert service bulletin. The manufacturer has advised the FAA
that procedures to remove the access panels were inadvertently included
in the alert service bulletin and will be removed at the next revision
of the alert service bulletin.
Although the alert service bulletin describes procedures
for performing the visual inspection using a borescope, the
manufacturer has advised the FAA that the option of performing the
visual inspection using a mirror was inadvertently omitted from the
alert service bulletin. Moreover, Figure 1 of the Accomplishment
Instructions of the alert service bulletin specifies that the subject
area can be examined with a borescope or mirror. Therefore, the FAA has
included the option of using a mirror as an acceptable method of
compliance with the visual inspection requirements of this AD.
Interim Action
This is considered to be interim action. The FAA is currently
considering requiring the modification of the rear spar web of the wing
center section, which will constitute terminating action for the
repetitive inspections required by this AD. However, the planned
compliance time for the installation of the modification is
sufficiently long so that notice and opportunity for prior public
comment will be practicable.
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 97-NM-282-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
[[Page 65357]]
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:
97-25-15 Boeing: Amendment 39-10239. Docket 97-NM-282-AD.
Applicability: Model 727 series airplanes having line numbers
858 through 864 inclusive, 867 through 869 inclusive, 872 through
883 inclusive, and 885 through 1832 inclusive; certificated in any
category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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 detect and correct cracking of the rear spar web, which could
permit fuel leakage into the airflow multiplier, and could result in
an electrical short that could cause a fire, accomplish the
following:
(a) Prior to the accumulation of 15,000 total flight cycles, or
within 300 flight cycles after the effective date of this AD,
whichever occurs later: Accomplish the inspections specified in
either paragraph (a)(1) or (a)(2) of this AD, in accordance with
Boeing Alert Service Bulletin 727-57A0182, dated September 18, 1997.
For purposes of this AD, the access panels specified in the alert
service bulletin need not be removed; the access panels need only be
opened.
Note 2: The fuel tank of the wing center section may be filled
with fuel to assist in detecting cracking or fuel leakage during the
accomplishment of the visual inspections required by this AD.
(1) Perform a visual inspection using a borescope or mirror to
detect cracking of the rear spar web and/or fuel leakage of the wing
center section between Right Body Buttock Line (BBL) 40 and Left BBL
40, in accordance with Part I of the Accomplishment Instructions of
the alert service bulletin. Thereafter, repeat this inspection at
intervals not to exceed 300 flight cycles. Or
(2) Perform an ultrasonic and high frequency eddy current (HFEC)
inspection to detect cracking of the rear spar web of the wing
center section between Right BBL 40 and Left BBL 40, in accordance
with Part II of the Accomplishment Instructions of the alert service
bulletin. Thereafter, repeat this inspection at intervals not to
exceed 3,000 flight cycles.
(b) If any cracking of the rear spar web and/or fuel leakage of
the wing center section is detected between Right BBL 40 and Left
BBL 40 near the upper machined land radius, prior to further flight,
repair in accordance with Part III of the Accomplishment
Instructions in Boeing Alert Service Bulletin 727-57A0182, dated
September 18, 1997. Accomplishment of this repair constitutes
terminating action for the repetitive inspection requirements of
this AD.
(c) If any cracking of the rear spar web and/or fuel leakage of
the wing center section is detected that is outside the area
specified in paragraph (b) of this AD, prior to further flight,
repair in accordance with a method approved by the Manager, Seattle
Aircraft Certification Office (ACO), FAA, Transport Airplane
Directorate.
(d) Accomplishment of paragraphs (d)(1) and either (d)(2) or
(d)(3) of this AD, as applicable, constitute terminating action for
the repetitive inspection requirements of this AD.
(1) Accomplish an ultrasonic and HFEC inspection in accordance
with the requirements of paragraph (a)(2) of this AD. And,
(2) If no cracking is detected, prior to further flight, modify
the rear spar web of the center section of the fuel tank between
Right BBL 40 and Left BBL 40, in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin 727-57A0182, dated
September 18, 1997.
(3) If any cracking is detected, prior to further flight, repair
in accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin 727-57A0182, dated September 18, 1997.
(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 ACO. 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 Manager, Seattle ACO.
(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, provided the
limitations specified in paragraphs (f)(1) through (f)(6) of this AD
are included in the special flight permit:
``(1) Required trip and reserve fuel must be carried in the No.
1 and No. 3 outer wing tanks.
(2) Wing center tank No. 2 must be empty of fuel.
(3) The fuel system must be checked for normal operation prior
to flight by verifying that all boost pumps are operational;
configuring the fuel system by turning on all boost pumps in the No.
1 and 3 outer wing tanks and by opening all crossfeed valve
selectors; and by confirming that fuel is not bypassing tank No. 2
check valves by observing that there is no leakage into tank No. 2.
(4) Maintain a minimum of 5,300 pounds of fuel in tanks No. 1
and No. 3 to prevent uncovering the fuel bypass valve.
(5) The fuel quantity indication system must be operational in
all three tanks.
(6) The effects of loading fuel only in the wing tanks on the
airplane weight and balance must be considered and accounted for.''
(g) Except as provided by paragraph (c) of this AD, the actions
shall be done in accordance with Boeing Alert Service Bulletin 727-
57A0182, dated September 18, 1997. 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 December 29, 1997.
Issued in Renton, Washington, on December 3, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-32233 Filed 12-11-97; 8:45 am]
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