[Federal Register Volume 62, Number 248 (Monday, December 29, 1997)]
[Rules and Regulations]
[Pages 67550-67551]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-33668]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-294-AD; Amendment 39-10264; AD 97-26-21]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100, 747-200, 747-300,
747SR, and 747SP 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 747-100, 747-200, 747-300, 747SR,
and 747SP series airplanes. This action requires a one-time inspection
to detect cracking of the longeron splice fittings at stringer 11, on
the left and right sides at body station 2598, and replacement of any
cracked fitting with a new fitting. This amendment is prompted by
reports that fatigue cracking was found on longeron splice fittings.
The actions specified in this AD are intended to detect and correct
such fatigue cracking, which could result in reduced controllability of
the horizontal stabilizer.
DATES: Effective January 13, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of January 13, 1998.
Comments for inclusion in the Rules Docket must be received on or
before February 27, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-294-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: Bob Breneman, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington; telephone (425) 227-2776;
fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: The FAA has received three reports
indicating that fatigue cracking was found on the longeron splice
fittings at stringer 11 on Boeing Model 747SR and 747-200 series
airplanes. The most recent cracking was detected on an airplane that
had accumulated 62,783 total flight hours and 16,867 total flight
cycles. Such fatigue cracking, if not detected and corrected in a
timely manner, could result in reduced controllability of the
horizontal stabilizer.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
747-53A2410, Revision 2, dated October 30, 1997, including Addendum,
which describes procedures for repetitive detailed inspections to
detect cracking of the longeron splice fittings at stringer 11, on the
left and right sides at body station 2598, and replacement of any
cracked fitting with a new fitting. The alert service bulletin
specifies various compliance times for groups of airplanes having
different flight hour and flight cycle thresholds.
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 747-100, 747-200, 747-300,
747SR, and 747SP series airplanes of the same type design, this AD
requires a one-time detailed inspection to detect cracking of the
longeron splice fittings at stringer 11, on the left and right sides at
body station 2598, and replacement of any cracked fitting with a new
fitting. The actions are required to be accomplished in accordance with
the alert service bulletin described previously.
Differences Between the AD and the Alert Service Bulletin
The AD differs from the previously described alert service bulletin
in that the AD requires a one-time inspection and shortened compliance
time, rather than the repetitive inspections and multiple compliance
times specified in the referenced alert service bulletin. The recent
report of cracking detected on a Boeing Model 747-200 series airplane
at a relatively low threshold has indicated the need for interim action
requiring inspection at an early date, directed to those airplanes that
have accumulated the highest number of flight hours or flight cycles
(i.e., 78,000 total flight hours or 22,000 total flight cycles).
In addition, the AD differs from the alert service bulletin by
providing a compliance period in terms of calendar time, rather than
flight cycles/hours, for those airplanes that have exceeded the
threshold. Due to the limited availability of replacement fittings, a
90-day compliance period is provided by this AD. This compliance period
will allow the operators of affected airplanes an opportunity to
schedule the inspection and have necessary replacement fittings
available if cracks are found during the inspection.
Interim Action
This AD is considered to be interim action. The FAA is considering
separate rulemaking action that would propose similar inspections at
repetitive intervals for all airplanes affected by the previously
described alert service bulletin.
[[Page 67551]]
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-294-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:
97-26-21 Boeing: Amendment 39-10264. Docket 97-NM-294-AD.
Applicability: Model 747-100, 747-200, 747-300, 747SR, and 747SP
series airplanes having line positions 201 through 886 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 (b) 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 fatigue cracking of the longeron splice
fittings at stringer 11, which could result in reduced
controllability of the horizontal stabilizer, accomplish the
following:
(a) Perform a one-time detailed visual inspection to detect
cracking of the longeron fittings at stringer 11, on the left and
right sides at body station 2598, at the later of the times
specified in paragraphs (a)(1) and (a)(2) of this AD, in accordance
with the Accomplishment Instructions of Boeing Alert Service
Bulletin 747-53A2410, Revision 2, dated October 30, 1997, including
Addendum. If any crack is detected, prior to further flight, replace
the cracked fitting with a new fitting, in accordance with the alert
service bulletin.
(1) Inspect prior to the accumulation of 22,000 total flight
cycles or 78,000 total flight hours, whichever occurs first; or
(2) Inspect within 90 days after the effective date of this AD.
Note 2: Where there are differences between the AD and the alert
service bulletin, the AD prevails.
(b) 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.
(c) 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.
(d) The actions shall be done in accordance with Boeing Alert
Service Bulletin 747-53A2410, Revision 2, dated October 30, 1997,
including Addendum. 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.
(e) This amendment becomes effective on January 13, 1998.
Issued in Renton, Washington, on December 19, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-33668 Filed 12-24-97; 8:45 am]
BILLING CODE 4910-13-U
