[Federal Register: April 17, 2003 (Volume 68, Number 74)]
[Proposed Rules]
[Page 18908-18910]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17ap03-20]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NM-324-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
[[Page 18909]]
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Boeing Model 747 series
airplanes. This proposal would require repetitive inspections for
discrepancies of certain areas of the forward and aft sides of the body
station 2598 bulkhead, and repair if necessary. This action is
necessary to find and fix such discrepancies of the bulkhead structure,
which could result in failure of the structure to carry flight loads of
the horizontal stabilizer, and consequent loss of controllability of
the airplane. This action is intended to address the identified unsafe
condition.
DATES: Comments must be received by June 2, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2001-NM-324-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:
9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must
contain ``Docket No. 2001-NM-324-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: Rick Kawaguchi, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6434; fax (425) 917-6590.
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:
[sbull] 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.
[sbull] For each issue, state what specific change to the proposed
AD is being requested.
[sbull] 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 2001-NM-324-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. 2001-NM-324-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received several reports of fatigue cracking in the
bulkhead inner chords, outer chords, and diagonal brace attachment
fittings on certain Boeing Model 747 series airplanes. The cracks
ranged from 0.4 inch to 2.0 inches long and have been found on both the
left and right sides of the bulkhead structure. These airplanes had
accumulated between 5,982 and 18,487 total flight cycles. In addition,
elongated fastener holes have been found in the diagonal brace rods on
several airplanes. Such discrepancies of the bulkhead structure, if not
found and fixed, could result in failure of the structure to carry
flight loads of the horizontal stabilizer, and consequent loss of
controllability of the airplane.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
747-53A2467, including Evaluation Form, dated July 26, 2001, which
describes procedures for repetitive detailed inspections of the body
station 2598 bulkhead for discrepancies (cracking, elongated fastener
holes) of the lower aft inner chords; upper aft outer chords; and
diagonal brace attachment fittings, flanges, and rods and repair of any
cracking or elongated fastener holes, if necessary. The service
bulletin also specifies contacting Boeing for repair procedures for
cracking of the outer chord. Accomplishment of the actions specified in
the service bulletin is intended to adequately address the identified
unsafe condition.
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 require accomplishment of the actions specified in
the service bulletin described previously, except as discussed below.
Difference Between This Proposed AD and the Service Information
Although the service bulletin specifies that the manufacturer may
be contacted for disposition of certain repair conditions, this
proposed AD would require the repair of those conditions to be
accomplished in accordance with a method approved by the FAA, or in
accordance with data meeting the type certification basis of the
airplane approved by a Boeing Company Designated Engineering
Representative who has been authorized by the FAA to make such
findings.
Interim Action
This is considered to be interim action. The manufacturer has
advised that it currently is developing a modification that will
address the unsafe condition identified in this AD. Once this
modification is developed, approved, and available, the FAA may
consider further rulemaking.
Cost Impact
There are approximately 1,147 airplanes of the affected design in
the worldwide fleet. The FAA estimates that 280 airplanes of U.S.
registry would be affected by this proposed AD, that it would take
approximately 4 work hours
[[Page 18910]]
per airplane to accomplish the proposed inspection, and that the
average labor rate is $60 per work hour. Based on these figures, the
cost impact of the proposed AD on U.S. operators is estimated to be
$67,200, or $240 per airplane.
The cost impact figure discussed above is 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 adding the following new
airworthiness directive:
Boeing: Docket 2001-NM-324-AD.
Applicability: Model 747 series airplanes, line numbers 1
through 1307 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
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 find and fix discrepancies of the bulkhead structure, which
could result in failure of the structure to carry flight loads of
the horizontal stabilizer, and consequent loss of controllability of
the airplane, accomplish the following:
Repetitive Inspections
(a) Before the accumulation of 10,000 total flight cycles or
within 1,000 flight cycles after the effective date of this AD,
whichever is later: Do a detailed inspection of the body station
2598 bulkhead for discrepancies (cracking, elongated fastener holes)
of the lower aft inner chords; upper aft outer chords; and diagonal
brace attachment fittings, flanges, and rods; per Boeing Alert
Service Bulletin 747-53A2467, excluding Evaluation Form, dated July
26, 2001. Repeat the inspection after that at intervals not to
exceed 3,000 flight cycles.
Note 2: For the purposes of this AD, a detailed inspection is
defined as: ``An intensive visual examination of a specific
structural area, system, installation, or assembly to detect damage,
failure, or irregularity. Available lighting is normally
supplemented with a direct source of good lighting at intensity
deemed appropriate by the inspector. Inspection aids such as mirror,
magnifying lenses, etc., may be used. Surface cleaning and elaborate
access procedures may be required.''
Repair
(b) If any discrepancy is found during any inspection required
by paragraph (a) of this AD: Before further flight, repair per
Boeing Alert Service Bulletin 747-53A2467, excluding Evaluation
Form, dated July 26, 2001. If any discrepancy is found and the
service bulletin specifies to contact Boeing for appropriate action:
Before further flight, repair per a method approved by the Manager,
Seattle Aircraft Certification Office (ACO), FAA; or per data
meeting the type certification basis of the airplane approved by a
Boeing Company Designated Engineering Representative who has been
authorized by the Manager, Seattle ACO, to make such findings. For a
repair method to be approved, the approval must specifically
reference this AD.
Alternative Methods of Compliance
(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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Special Flight Permit
(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.
Issued in Renton, Washington, on April 11, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 03-9432 Filed 4-16-03; 8:45 am]
BILLING CODE 4910-13-P