[Federal Register: May 19, 2004 (Volume 69, Number 97)]
[Proposed Rules]
[Page 28860-28863]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19my04-15]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NM-347-AD]
RIN 2120-AA64
Airworthiness Directives; Saab Model SAAB 2000 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Saab Model SAAB 2000
series airplanes. This proposal would require various repetitive
inspections for cracking of the drag and shear angles that attach the
nacelle to the front spar of the wing, and related corrective action.
The proposal also would require eventual modification of the drag and
shear angles, which would end the repetitive inspections. This action
is necessary to prevent fatigue cracking of the drag and shear angles,
which could result in reduced structural integrity of the nacelle and
wing. This action is intended to address the identified unsafe
condition.
DATES: Comments must be received by June 18, 2004.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2002-NM-347-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. 2002-NM-347-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 or 2000 or
ASCII text.
The service information referenced in the proposed rule may be
obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Link[ouml]ping, Sweden. This information may be examined at the
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Dan Rodina, Aerospace Engineer,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4057; telephone (425)
227-2125; fax (425) 227-1149.
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:
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.
For each issue, state what specific change to the proposed
AD is being requested.
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 2002-NM-347-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. 2002-NM-347-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Luftfartsverket (LFV), which is the airworthiness authority for
Sweden, notified the FAA that an unsafe condition may exist on certain
Saab Model SAAB 2000 series airplanes. The LFV advises that inspections
done by a full-scale fatigue unit have revealed cracks in the drag
angles that attach the nacelle to the wing box via the upper and lower
wing skin; and in the shear angles that attach the nacelle to the front
spar of the wing. Fatigue cracking of the drag and shear angles of the
front spar of the wing could result in reduced structural integrity of
the nacelle and wing.
Explanation of Relevant Service Information
The manufacturer has issued Saab Service Bulletins 2000-54-026,
Revision 01, and 2000-54-028, Revision 01, both dated June 20, 2002.
The service bulletins describe procedures for
[[Page 28861]]
repetitive inspections for cracking and related corrective action.
Service Bulletin 2000-54-026, Revision 01, describes procedures for
detailed visual and eddy current inspections of the shear angles which
attach the nacelle to the front spar of the wing; Service Bulletin
2000-54-028, Revision 01, describes procedures for endoscope
inspections of the drag angles which attach the nacelle to the wing box
via the upper and lower wing skin. If any cracking is found, both
service bulletins specify following Table 1 of the Accomplishment
Instructions to determine the proper action (which includes repeating
the inspections at certain intervals, depending on the length of the
crack). Both service bulletins also recommend contacting the
manufacturer if the cracking exceeds certain damage specifications in
Table 1, and sending an inspection report to the manufacturer for
further corrective action.
Additionally, the manufacturer has issued Saab Service Bulletins
2000-54-027, and 2000-54-029, both dated November 4, 2002, which
describe procedures for modification of the upper and lower drag angles
and the shear angles which attach the nacelle to the front spar of the
wing. Accomplishment of both modifications eliminates the need for the
repetitive inspections. The modification procedures in Service Bulletin
2000-54-027 include an eddy current inspection of the surface of the
shear angles and a rotating probe inspection of the hi-lok holes for
cracking. If no cracking is found, the service bulletin describes
procedures for installation of pressure pads on the shear angles. The
modification procedures in Service Bulletin 2000-54-029 include an eddy
current (rotating probe) inspection of the upper and lower drag angles
for cracking. If no cracking is found, the service bulletin describes
procedures for installation of pressure pads on the drag angles. If any
cracking is found, both service bulletins describe procedures for
determining the length and position of each crack, and sending a report
to the manufacturer for further corrective action.
Accomplishment of the actions specified in the service information
is intended to adequately address the identified unsafe condition. The
LFV classified this service information as mandatory and issued Swedish
airworthiness directives 1-174 and 1-175, both dated April 30, 2002;
and 1-180 and 1-181, both dated November 8, 2002; to ensure the
continued airworthiness of these airplanes in Sweden.
FAA's Conclusions
This airplane model is manufactured in Sweden and is type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, the LFV has kept us informed of the
situation described above. We have examined the findings of the LFV,
reviewed all available information, and determined that AD action is
necessary for products of this type design that are certificated for
operation in the United States.
Explanation of Requirements of Proposed AD
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, the proposed AD would require accomplishment of
the actions specified in the service information described previously,
except as discussed below.
Differences Among Swedish Airworthiness Directives, Service
Information, and Proposed AD
Unlike the procedures described in the service bulletins, and
referenced in the Swedish airworthiness directives, this proposed AD
would not permit further flight if cracks are found in the drag and
shear angles. We have determined that, because of the safety
implications and consequences associated with such cracking, any
cracked drag or shear angle must be repaired before further flight.
The compliance time specified in the table in paragraph 1.D.,
`Compliance,' of Service Bulletin 2000-54-029 does not recommend a
specific compliance time for the modification of the drag angles. The
table cites cracking damage and different compliance times depending on
the severity of the damage; however, we have determined the
modification must be done before the accumulation of 24,000 flight
cycles, as specified in the column citing no crack damage.
Swedish airworthiness directives 1-174 and 1-175 require following
the repetitive inspection intervals specified in Table 1 of the
referenced service bulletins (determined by the severity of the
cracking); however, this proposed AD follows the repetitive inspection
interval in the column citing no crack damage as specified in Table 1
of Service Bulletin 2000-54-028, Revision 01, for all airplanes.
The compliance times specified above represent an appropriate
interval of time for affected airplanes to continue to operate without
compromising safety.
The referenced service bulletins specify that operators may contact
the manufacturer for disposition of certain repair (cracking)
conditions; however, this proposed AD would not allow this option but
would require operators to repair any cracking per a method approved by
either the FAA or the LFV (or its delegated agent). In light of the
type of repair that would be required to address the unsafe condition,
and consistent with existing bilateral airworthiness agreements, we
have determined that, for this proposed AD, a repair approved by either
the FAA or the LFV would be acceptable for compliance with this
proposed AD.
The referenced service bulletins also specify that operators may
contact the manufacturer to obtain repetitive inspection intervals if
the cracking exceeds certain parameters; however, we have determined
that operators must obtain appropriate repetitive inspection/repair
procedures from either the FAA or the LFV (or its delegated agent).
Although the service bulletins recommend that operators send the
manufacturer a report of the inspection results, this proposed AD would
not require submission of such a report.
The above differences have been coordinated with the LFV.
Clarification of Inspection Type
This proposed AD would specify a ``detailed'' inspection for
cracking of the shear angles which attach the nacelle to the front spar
of the wing, in lieu of a detailed ``visual'' inspection, as specified
in Service Bulletin 2000-54-026, Revision 01. A note has been added to
this proposed AD to define that inspection.
Cost Impact
We estimate that 3 airplanes of U.S. registry would be affected by
this proposed AD.
It would take about 6 work hours per airplane to do the proposed
inspections, at an average labor rate of $65 per work hour. Based on
these figures, the cost impact of the proposed inspections on U.S.
operators is estimated to be $1,170, or $390 per airplane, per
inspection cycle.
It would take about 40 work hours per airplane to do the proposed
modification of the shear angles, at an average labor rate of $65 per
work hour. Required parts would cost about $6,200 per airplane. Based
on these figures, the cost impact of the proposed modification on U.S.
operators is estimated to be $26,400, or $8,800 per airplane.
[[Page 28862]]
It would take about 400 work hours per airplane to do the proposed
modification of the drag angles, at an average labor rate of $65 per
work hour. Required parts would cost about $41,794 per airplane. Based
on these figures, the cost impact of the proposed modification on U.S.
operators is estimated to be $203,382, or $67,794 per airplane.
The cost impact figures discussed above are 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 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:
Saab Aircraft AB: Docket 2002-NM-347-AD.
Applicability: Model SAAB 2000 series airplanes, certificated in
any category, serial numbers -004 through -063 inclusive.
Compliance: Required as indicated, unless accomplished
previously.
To prevent fatigue cracking of the drag and shear angles of the
front spar of the wing, which could result in reduced structural
integrity of the nacelle and wing, accomplish the following:
Repetitive Inspections
(a) Do the inspections required by paragraphs (a)(1) and (a)(2)
of this AD, at the applicable time specified in paragraph (b) of
this AD.
(1) Do a detailed inspection for cracking of the shear angles
which attach the nacelle to the front spar of the wing, and an eddy
current inspection for cracking around the fasteners, by doing all
the actions per the Accomplishment Instructions of Saab Service
Bulletin 2000-54-026, Revision 01, dated June 20, 2002.
(2) Do an endoscope inspection of the upper and lower drag
angles for cracking, and an eddy current inspection for cracking
around the fasteners, by doing all the actions per the
Accomplishment Instructions of Saab Service Bulletin 2000-54-028,
Revision 01, dated June 20, 2002.
Note 1: 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.''
Compliance Times
(b) Do the inspections required by paragraph (a) of this AD at
the applicable compliance time specified in paragraph (b)(1),
(b)(2), or (b)(3) of this AD. Repeat the inspections thereafter at
intervals not to exceed 4,000 flight cycles until the modification
required by paragraph (e) of this AD is done.
(1) For airplanes that have accumulated 14,000 or more total
flight cycles as of the effective date of this AD: Inspect within
500 flight cycles after the effective date of this AD.
(2) For airplanes that have accumulated 10,000 or more total
flight cycles, but fewer than 14,000 total flight cycles as of the
effective date of this AD: Inspect within 1,000 flight cycles after
the effective date of this AD.
(3) For airplanes that have accumulated fewer than 10,000 total
flight cycles as of the effective date of this AD: Inspect within
2,000 flight cycles after the effective date of this AD.
Corrective Action
(c) If any cracking is found during any inspection required by
this AD: Before further flight, repair the cracking per a method
approved by either the Manager, International Branch, ANM-116,
Transport Airplane Directorate, FAA, or the LFV (or its delegated
agent). In lieu of repairing the cracking, the modifications
required by paragraph (e) of this AD may be done before further
flight, which would end the repetitive inspections required by
paragraphs (a) and (b) of this AD.
Inspections Done Per Previous Issues of Service Bulletins
(d) Inspections done before the effective date of this AD per
Saab Service Bulletins 2000-54-026 and 2000-54-028, both dated April
26, 2002, are considered acceptable for compliance with the
corresponding actions specified in this AD.
Terminating Action
(e) Except as provided by paragraph (c) of this AD: Do the
modifications of the drag and shear angles of the front spar of the
wing at the times specified in paragraphs (e)(1) and (e)(2) of this
AD. Accomplishment of these modifications ends the repetitive
inspections required by paragraphs (a) and (b) of this AD.
(1) Before the accumulation of 20,000 total flight cycles:
Modify the shear angles that attach the nacelle to the front spar of
the wing by doing all the actions per the Accomplishment
Instructions of Saab Service Bulletin 2000-54-027, dated November 4,
2002.
(2) Before the accumulation of 24,000 total flight cycles:
Modify the upper and lower drag angles by doing all the actions per
the Accomplishment Instructions of Saab Service Bulletin 2000-54-
029, dated November 4, 2002.
No Reporting Requirement
(f) Although the Saab Service Bulletins referenced in this AD
recommend submitting certain information to the manufacturer, this
AD does not include such a requirement.
Alternative Methods of Compliance
(g) In accordance with 14 CFR 39.19, the Manager, International
Branch, ANM-116, Transport Airplane Directorate, is authorized to
approve alternative methods of compliance for this AD.
Note 2: The subject of this AD is addressed in Swedish
airworthiness directives 1-174 and 1-175, both dated April 30, 2002;
and Swedish airworthiness directives 1-180 and 1-181, both dated
November 8, 2002.
[[Page 28863]]
Issued in Renton, Washington, on May 12, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-11291 Filed 5-18-04; 8:45 am]
BILLING CODE 4910-13-P