[Federal Register Volume 63, Number 148 (Monday, August 3, 1998)]
[Rules and Regulations]
[Pages 41184-41186]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20679]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-210-AD; Amendment 39-10689; AD 98-16-13]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 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 747 series airplanes. This action
requires a one-time inspection for missing fasteners of the splice
fitting of the forward inner chord of the Body Station (BS) 2598
bulkhead; and corrective actions, if necessary. This amendment is
prompted by a report that fasteners were missing from the splice
fitting of the forward inner chord. The actions specified in this AD
are intended to prevent accelerated fatigue cracking of the inner
chords of the BS 2598 bulkhead, which could result in inability of the
structure to carry horizontal stabilizer flight loads, and consequent
reduced controllability of the airplane.
DATES: Effective August 18, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of August 18, 1998.
Comments for inclusion in the Rules Docket must be received on or
before October 2, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-210-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
[[Page 41185]]
the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Bob Breneman, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2776; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: The FAA has received a report indicating
that fasteners were missing from the splice fitting of the forward
inner chord of the Body Station (BS) 2598 bulkhead on a Boeing Model
747 series airplane. The fasteners missing from the splice fitting
resulted in accelerated initiation and propagation of fatigue cracking
of both the forward and aft inner chords of the BS 2598 bulkhead. A
0.2-inch crack was found in the forward inner chord, and a 3.0-inch
horizontal crack and a 1.0-inch vertical crack were found in the aft
inner chord. Such fatigue cracking, if not corrected, could result in
inability of the structure to carry horizontal stabilizer flight loads,
and consequent reduced controllability of the airplane.
As a result of the report of missing fasteners, Boeing requested
that operators perform inspections on a limited number of delivered
airplanes. Sixteen airplanes were inspected, including ten that had
been delivered at approximately the same time as the airplane on which
cracks were found. The fasteners were found to be installed on all 16
of those airplanes. However, Boeing has not been able to provide
justification to limit the inspection for missing fasteners to a
specific group of airplanes, so this AD requires an inspection for
missing fasteners on all Boeing Model 747 series airplanes that have
been delivered.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
747-53A2423, dated June 11, 1998, which describes procedures for a one-
time visual inspection for missing fasteners of the splice fitting of
the forward inner chord of the BS 2598 bulkhead; and corrective
actions, if any fasteners are missing. The corrective actions include
performing a detailed visual inspection and a high frequency eddy
current inspection for cracking of the forward and aft inner chords of
the BS 2598 bulkhead, on the left and right sides of the airplane;
repair, if necessary; and installation of the fasteners.
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 prevent accelerated fatigue cracking of the inner
chords of the BS 2598 bulkhead, which could result in inability of the
structure to carry horizontal stabilizer flight loads, and consequent
reduced controllability of the airplane. This AD requires
accomplishment of the actions specified in the alert service bulletin
described previously, except as discussed below. This AD also requires
that operators report results of inspection findings (findings of
missing fasteners only) to the FAA.
Interim Action
This is considered to be interim action. There have been other
reports of fatigue cracking of the inner chords of the BS 2598
bulkhead, as well as cracking of repair angles that were installed to
correct cracks that were detected previously in the inner chords of the
bulkhead. The FAA is currently considering additional rulemaking to
further address the unsafe condition of fatigue cracking in the inner
chords of the BS 2598 bulkhead. However, the planned compliance time
for the corrective actions is sufficiently long so that notice and
opportunity for prior public comment will be practicable.
Differences Between This Rule and Alert Service Bulletin
Operators should note that the statement of effectivity in the
alert service bulletin does not include the Boeing Model 747 series
airplane having line position 1155. That airplane is currently in
storage and has not been delivered. Boeing is under contract to
accomplish any required inspections prior to delivery of the airplane.
Therefore, the applicability statement of this AD includes this
airplane.
Operators also should note that, although the alert service
bulletin specifies that the manufacturer may be contacted for
disposition of certain repair conditions, this AD requires the repair
of those conditions to be accomplished in accordance with Boeing 747
Structural Repair Manual (SRM) 53-10-04, Figure 72; or Boeing 747SP SRM
53-19-02, Figure 41; as applicable; or in accordance with a method
approved by the FAA.
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-210-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,
[[Page 41186]]
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:
98-16-13 Boeing: Amendment 39-10689. Docket 98-NM-210-AD.
Applicability: Model 747 series airplanes, line positions 1
through 1157; 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 accelerated fatigue cracking of the inner chords of
the Body Station (BS) 2598 bulkhead, which could result in inability
of the structure to carry horizontal stabilizer flight loads, and
consequent reduced controllability of the airplane; accomplish the
following:
(a) Prior to the accumulation of 8,000 total flight cycles, or
within 90 days after the effective date of this AD, whichever occurs
later, perform a one-time visual inspection for missing fasteners of
the splice fitting of the forward inner chord of the BS 2598
bulkhead, on the left and right sides of the airplane, in accordance
with Boeing Alert Service Bulletin 747-53A2423, dated June 11, 1998.
(1) If all fasteners are present, no further action is required
by this AD.
(2) If any fastener is missing, prior to further flight,
accomplish a detailed visual inspection and a high frequency eddy
current inspection to detect cracking of the forward and aft inner
chords of the BS 2598 bulkhead, on the left and right sides of the
airplane; in accordance with the alert service bulletin.
(i) If no cracking is detected, prior to further flight, install
the fasteners, in accordance with the alert service bulletin.
(ii) If any cracking is detected, prior to further flight,
repair the cracking and install the fasteners, in accordance with
Boeing 747 Structural Repair Manual (SRM) 53-10-04, Figure 72, or
Boeing 747SP SRM 53-19-02, Figure 41; as applicable; or repair in
accordance with a method approved by the Manager, Seattle Aircraft
Certification Office (ACO), FAA, Transport Airplane Directorate.
(b) Within 10 days after accomplishing the inspection required
by paragraph (a) of this AD, submit a report of the inspection
results (findings of missing fasteners only) to the Manager, Seattle
Manufacturing Inspection District Office, FAA, Transport Airplane
Directorate, 2500 East Valley Road, suite C-2, Renton, Washington
98055-4056; fax (425) 227-1181. Information collection requirements
contained in this regulation have been approved by the Office of
Management and Budget (OMB) under the provisions of the Paperwork
Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been
assigned OMB Control Number 2120-0056.
(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 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 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) Except as provided by paragraph (a)(2)(ii) of this AD, the
actions shall be done in accordance with Boeing Alert Service
Bulletin 747-53A2423, dated June 11, 1998. 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.
(f) This amendment becomes effective on August 18, 1998.
Issued in Renton, Washington, on July 27, 1998.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-20679 Filed 7-31-98; 8:45 am]
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