[Federal Register Volume 59, Number 2 (Tuesday, January 4, 1994)]
[Proposed Rules]
[Pages 265-266]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-23]
[[Page Unknown]]
[Federal Register: January 4, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 93-NM-174-AD]
Airworthiness Directives; Boeing Model 747 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 747
series airplanes, that currently requires that the FAA-approved
maintenance inspection program include inspections which will give no
less than the required damage tolerance rating (DTR) for each
Structural Significant Item (SSI). This action would require the
inclusion of additional airplanes to the candidate fleet. This proposal
is prompted by a recommendation from the Airworthiness Assurance Task
Force, Model 747 Structures Working Group. The actions specified by the
proposed AD are intended to ensure the continued structural integrity
of the total Boeing Model 747 fleet.
DATES: Comments must be received by March 1, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 93-NM-174-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.
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: Steven Fox, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (206) 227-2777; fax (206) 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 notice may be changed in
light of the comments received.
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 notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 93-NM-174-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-103, Attention: Rules
Docket No. 93-NM-174-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On March 18, 1993, the FAA issued AD 93-06-01, Amendment 39-8526
(58 FR 19571, April 15, 1993), applicable to certain Boeing Model 747
series airplanes, to require that the FAA-approved maintenance
inspection program be revised to include inspections which will give no
less than the required damage tolerance rating (DTR) for each
Structural Significant Item (SSI). That action was prompted by a
structural re-evaluation by the manufacturer which identified
additional structural elements where, if damage should occur,
supplemental inspections may be required for timely detection. The
requirements of that AD are intended to ensure the continued structural
integrity of the total Boeing Model 747 fleet.
Since the issuance of that AD, the FAA has reviewed and approved
Boeing Document No. D6-35022, Volumes 1 and 2, ``Supplemental
Structural Inspection Document (SSID) for Model 747 Airplanes,''
Revision E, dated June 17, 1993, that revises the effectivity by adding
airplanes to the candidate fleet on which supplemental inspections that
give no less than the required damage tolerance rating (DTR) for each
Structural Significant Item (SSI) must be performed. This document also
clarifies the selection criteria for candidate airplanes. The original
Model 747-100 and -200 series airplanes in the candidate fleet were
selected based on having accumulated 10,000 flight cycles by June 30,
1983. Subsequently, selected high time airplanes were added to the
candidate fleet to replace out-of-service airplanes. Incorporation of
the inspections described in this document will ensure the continuing
structural integrity of the total Boeing Model 747 fleet.
Since the failure of an SSI can compromise the structural integrity
of these airplanes, and since such conditions are likely to exist or
develop on other Model 747 series airplanes, the proposed AD would
supersede AD 93-06-01 to expand the applicability to require that the
inspections identified in the Boeing document, described previously, be
performed on the airplanes in the candidate fleet to provide no less
than the required damage tolerance rating (DTR) for each Structural
Significant Item (SSI) listed in Revision E of the SSID.
Moreover, the FAA has identified eight additional airplanes that
are not listed in Revision E of the Boeing Document, and that must be
added to the candidate fleet to replace certain airplanes that were
removed from the candidate fleet. Some of these newly identified
airplanes were operated as short range (SR) airplanes and have now been
converted to freighters. Therefore, the FAA has determined that these
airplanes must be included in the SSID program, and that supplemental
inspections must also be performed on these additional airplanes to
ensure safety of the entire Boeing Model 747 fleet. The AD proposes to
expand the applicability by adding these eight airplanes.
There are approximately 128 Boeing Model 747 series airplanes of
the affected design in the worldwide fleet. The FAA estimates that 87
airplanes of U.S. registry and 8 U.S. operators would be affected by
this proposed AD. Incorporation of the SSID program into an operator's
maintenance program, as required by AD 93-06-01, and retained in this
proposal, is estimated to necessitate 1,000 work hours (per operator)
at an average labor rate of $55 per work hour. Based on these figures,
the total cost to the 8 affected U.S. operators to incorporate the SSID
program is estimated to be $440,000, or $55,000 per U.S. operator.
The recurring inspections costs, as required by AD 93-06-01, and
retained in this proposal, is estimated to be 1,275 work hours per
airplane at an average labor rate of $55 per work hour. Based on these
figures, the annual recurring cost required by AD 93-06-01, and
retained in this proposal, is estimated to be $6,100,875 for the
affected U.S. fleet, or $70,125 per airplane.
Since no new operators have been added by this proposal, there will
be no new costs associated with incorporating the SSID program into an
operator's maintenance program. Therefore, the future economic cost
impact of this proposal on U.S. operators is now only the cost of the
recurring inspections for these additional airplanes.
The number of required work hours for the recurring inspections in
this proposal, as indicated above, is presented as if the
accomplishment of the actions were to be conducted as ``stand alone''
action. However, in actual practice, these actions, for the most part,
would be accomplished coincidentally or in combination with normally
scheduled airplane inspections and other maintenance program tasks.
Therefore, the actual number of necessary additional work hours will be
minimal in many instances. Additionally, any costs associated with
special airplane scheduling will be minimal.
The regulations proposed herein would 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
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
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 14
CFR part 39 of the Federal Aviation Regulations as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-8526 (58 FR
19571, April 15, 1993), and by adding a new airworthiness directive
(AD), to read as follows:
Boeing: Docket 93-NM-174-AD. Supersedes AD 93-06-01, Amendment 39-
8526.
Applicability: Model 747 series airplanes, as listed in Section
3.0 of Boeing Document No. D6-35022, Volumes 1 and 2, ``Supplemental
Structural Inspection Document (SSID) for Model 747 Airplanes,''
Revision E, dated June 17, 1993; and manufacturer's line numbers 42,
174, 221, 231, 234, 239, 242, and 254; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To ensure the continued structural integrity of the total Boeing
Model 747 fleet, accomplish the following:
(a) For airplanes listed in Boeing Document No. D6-35022,
Volumes I and II, ``Supplemental Structural Inspection Document
(SSID),'' Revision D, dated February 1992: Within 12 months after
May 17, 1993 (the effective date of AD 93-06-01, Amendment 39-8526),
incorporate a revision into the FAA-approved maintenance inspection
program which provides no less than the required Damage Tolerance
Rating (DTR) for each Structural Significant Item (SSI) listed in
Boeing Document No. D6-35022, Revision D, dated February 1992. (The
required DTR value for each SSI is listed in the document.) The
revision to the maintenance program shall include Sections 5.0 and
6.0 of the SSID and shall be implemented in accordance with the
procedures contained in those sections.
(b) For airplanes listed in Boeing Document No. D6-35022,
Volumes 1 and 2, ``Supplemental Structural Inspection Document
(SSID) for Model 747 Airplanes,'' Revision E, dated June 17, 1993;
and manufacturer's line numbers 42, 174, 221, 231, 234, 239, 242,
and 254: Within 12 months after the effective date of this AD,
replace the revision of the FAA-approved maintenance inspection
program required by paragraph (a) of this AD with a revision that
provides no less than the required DTR for each SSI listed in Boeing
Document No. D6-35022, Volumes 1 and 2, ``Supplemental Structural
Inspection Document (SSID) for Model 747 Airplanes,'' Revision E,
dated June 17, 1993. (The required DTR value for each SSI is listed
in the document.) The revision to the maintenance program shall
include Sections 5.0 and 6.0 of the SSID and shall be implemented in
accordance with the procedures contained in those sections.
(c) Cracked structure must be repaired, prior to further flight,
in accordance with an FAA-approved method.
(d) 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: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(e) Special flight permits may be issued in accordance with FAR
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 December 28, 1993.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-23 Filed 1-3-94; 8:45 am]
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