[Federal Register Volume 64, Number 135 (Thursday, July 15, 1999)]
[Proposed Rules]
[Pages 38150-38152]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-18100]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-220-AD]
RIN 2120-AA64
Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Supplemental notice of proposed rulemaking; reopening of
comment period.
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SUMMARY: This document revises an earlier proposed airworthiness
directive (AD), applicable to certain Saab Model SAAB SF340A and SAAB
340B series airplanes, that would have required repetitive inspections
to detect cracking around certain fastener holes and adjacent areas of
the front spar of the horizontal stabilizers; and corrective actions,
if necessary. That proposal also would have required cold working of
certain fastener holes of the front spar of the horizontal stabilizers,
and follow-on actions; and installation of new fasteners, which would
have constituted terminating action for the repetitive inspections
proposed by that AD. That proposal was prompted by the issuance of
mandatory continuing airworthiness information by a foreign civil
airworthiness authority. This new action revises the proposed rule by
adding repetitive x-ray inspections. The actions specified by this new
proposed AD are intended to prevent failure of the front spar due to
fatigue cracking around certain fastener holes of the front spar of the
horizontal stabilizers, which could result in reduced structural
integrity of the airplane.
DATES: Comments must be received by August 9, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-220-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 Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Linkoping, Sweden. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW, Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2110; 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 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 98-NM-220-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. 98-NM-220-AD, 1601 Lind Avenue, SW, Renton, Washington
98055-4056.
Discussion
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to add an airworthiness directive (AD), applicable to
certain Saab Model SAAB SF340A and SAAB 340B series airplanes, was
published as a notice of proposed rulemaking (NPRM) in the Federal
Register on February 18, 1999 (64 FR 8029). That NPRM would have
required repetitive inspections to detect cracking around certain
fastener holes and adjacent areas of the front spar of the horizontal
stabilizers; and corrective actions, if necessary. That proposal also
would have required cold working of certain fastener holes of the front
spar of the horizontal stabilizers, and follow-on actions; and
installation of new fasteners, which would have constituted terminating
action for the repetitive inspections proposed by that AD. That NPRM
was prompted by the issuance of mandatory continuing airworthiness
information by a foreign civil airworthiness authority. Fatigue
cracking around certain fastener holes of the front spar of the
horizontal stabilizers, if not detected and corrected, could result in
failure of the front spar and consequent reduced structural integrity
of the airplane.
Comments
Due consideration has been given to the comments received in
response to the NPRM.
Request To Revise Certain Inspection Requirement of the Proposed
Rule
One commenter, the airplane manufacturer, requests that the
originally proposed rule be revised to clarify certain requirements.
The commenter notes that the originally proposed rule would require,
among other things, repetitive eddy current inspections to be
accomplished in accordance with Saab Service Bulletin 340-55-033,
Revision 04, dated December 1, 1998. The commenter points out that the
Saab service bulletin recommends performing both eddy current and x-ray
inspections. Under the compliance section of the service bulletin, the
general term ``NDT inspection'' is used. The commenter suggests that
either ``NDT inspection'' or ``eddy current and x-ray inspection'' be
specified in the requirements.
The FAA concurs with this request. The FAA inadvertently omitted
the reference to repetitive x-ray inspections in paragraphs (a) and (b)
of the proposed AD, and has revised this supplemental NPRM accordingly.
Additionally, the reference to x-ray inspections has been added to the
cost impact section of this supplemental NPRM. The original cost
estimate in the NPRM included all costs associated with both the eddy
current and x-ray inspections.
[[Page 38151]]
Since adding an inspection expands the scope of the originally
proposed rule, the FAA has determined that it is necessary to reopen
the comment period to provide additional opportunity for public
comment.
Clarification of the Inspection Requirements
Additionally, the FAA has clarified certain wording in the
supplemental NPRM to more accurately describe the inspection
requirements. This clarification is in addition to the previously
discussed omission. Paragraphs (a) and (b) of the proposed rule require
performing inspections to detect cracking around certain fastener holes
and adjacent areas of the front spar of the horizontal stabilizer. For
clarification of the types of inspections required, paragraphs (a) and
(b) of the supplemental NPRM have been revised to specify that detailed
visual, eddy current, and x-ray inspections are required in accordance
with paragraph 2.D. of the Accomplishment Instructions of the service
bulletin.
Cost Impact
The FAA estimates that 279 airplanes of U.S. registry would be
affected by this proposed AD.
It would take approximately 4 work hours per airplane to perform
the proposed detailed visual inspection, at an average labor rate of
$60 per work hour. Based on these figures, the cost impact of the
inspection proposed by this AD on U.S. operators is estimated to be
$66,960, or $240 per airplane, per inspection cycle.
It would take approximately 6 work hours per airplane to accomplish
the proposed eddy current and x-ray inspections, at an average labor
rate of $60 per work hour. Based on these figures, the cost impact of
the inspections proposed by this AD on U.S. operators is estimated to
be $100,440, or $360 per airplane, per inspection cycle.
It would take approximately 42 work hours to accomplish the cold
working of the fastener holes, at an average labor rate of $60 per work
hour. Required parts would cost approximately $400 per airplane. Based
on these figures, the cost impact of the cold work proposed by this AD
on U.S. operators is estimated to be $814,680, or $2,920 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.
Regulatory Impact
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
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 98-NM-220-AD.
Applicability: Model SAAB SF340A series airplanes,
manufacturer's serial numbers -004 through -159 inclusive; and SAAB
340B series airplanes, manufacturer's serial numbers -160 through -
439 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 (f) 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 failure of the front spar due to fatigue cracking
around certain fastener holes of the front spar of the horizontal
stabilizers, which could result in reduced structural integrity of
the airplane, accomplish the following:
Initial and Repetitive Inspections
(a) For Model SAAB SF340A series airplanes with manufacturer's
serial numbers -004 through -159 inclusive: Perform the inspections
(detailed visual, eddy current, and x-ray) specified in paragraph
2.D. of the Accomplishment Instructions of Saab Service Bulletin
340-55-033, Revision 04, dated December 1, 1998, to detect cracking
around certain fastener holes and adjacent areas of the front spar
of the horizontal stabilizer, in accordance with the service
bulletin, at the time specified in paragraph (a)(1), (a)(2), or
(a)(3) of this AD, as applicable. Thereafter, repeat only the eddy
current and x-ray inspections at intervals not to exceed 12,000
flight cycles until the requirements of paragraph (d) of this AD are
accomplished.
(1) For airplanes that have accumulated less than 22,000 total
flight cycles as of the effective date of this AD: Perform an eddy
current and an x-ray inspection prior to the accumulation of 22,000
total flight cycles, or within 2,000 flight cycles after the
effective date of this AD, whichever occurs later.
(2) For airplanes that have accumulated 22,000 or more total
flight cycles and less than 30,000 total flight cycles as of the
effective date of this AD: Accomplish the requirements of paragraphs
(a)(2)(i) and (a)(2)(ii) of this AD.
(i) Perform a detailed visual inspection within 800 flight
cycles after the effective date of this AD; and
(ii) Perform an eddy current and an x-ray inspection within
2,000 flight cycles after the effective date of this AD.
(3) For airplanes that have accumulated 30,000 or more total
flight cycles as of the effective date of this AD: Accomplish the
requirements of paragraphs (a)(3)(i) and (a)(3)(ii) of this AD.
(i) Perform a detailed visual inspection within 400 flight
cycles after the effective date of this AD; and
(ii) Perform an eddy current and an x-ray inspection within
1,200 flight cycles after the effective date of this AD.
Initial and Repetitive Inspections
(b) For Model SAAB 340B series airplanes with manufacturer's
serial numbers -160 through -439 inclusive: Perform the inspections
(detailed visual, eddy current, and x-ray) specified in paragraph
2.D. of the Accomplishment Instructions of Saab Service Bulletin
340-55-033, Revision 04, dated
[[Page 38152]]
December 1, 1998, to detect cracking around certain fastener holes
and adjacent areas of the front spar of the horizontal stabilizer,
in accordance with the service bulletin, at the time specified in
paragraph (b)(1), (b)(2), or (b)(3) of this AD, as applicable.
Thereafter, repeat only the eddy current and x-ray inspections at
intervals not to exceed 6,000 flight cycles until the requirements
of paragraph (d) of this AD are accomplished.
(1) For airplanes that have accumulated less than 12,000 total
flight cycles as of the effective date of this AD: Perform an eddy
current and an x-ray inspection prior to the accumulation of 12,000
total flight cycles, or within 2,000 flight cycles after the
effective date of this AD, whichever occurs later.
(2) For airplanes that have accumulated 12,000 or more total
flight cycles and less than 16,000 total flight cycles as of the
effective date of this AD: Accomplish the requirements of paragraphs
(b)(2)(i) and (b)(2)(ii) of this AD.
(i) Perform a detailed visual inspection within 800 flight
cycles after the effective date of this AD; and
(ii) Perform an eddy current and an x-ray inspection within
2,000 flight cycles after the effective date of this AD.
(3) For airplanes that have accumulated 16,000 or more total
flight cycles as of the effective date of this AD: Accomplish the
requirements of paragraphs (b)(3)(i) and (b)(3)(ii) of this AD.
(i) Perform a detailed visual inspection within 400 flight
cycles after the effective date of this AD; and
(ii) Perform an eddy current and an x-ray inspection within
1,200 flight cycles after the effective date of this AD.
Corrective Actions
(c) If any cracking is detected during any inspection required
by paragraph (a) or (b) of this AD, prior to further flight, either
repair in accordance with a method approved by the Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
or the Luftfartsverket (LFV) (or its delegated agent); or accomplish
the requirements of paragraph (d) of this AD.
Note 2: Inspections to detect cracking around certain fastener
holes and adjacent areas of the front spar of the horizontal
stabilizers that have been accomplished prior to the effective date
of this AD in accordance with Saab Service Bulletin 340-55-033,
Revision 03, dated January 22, 1998, are considered acceptable for
compliance with the applicable action specified by this AD.
Terminating Action
(d) For all airplanes: Except as provided by paragraph (e) of
this AD, accomplish cold working of certain fastener holes of the
front spar of the horizontal stabilizers, and follow-on actions; and
install new fasteners; in accordance with Saab Service Bulletin 340-
55-034, dated October 16, 1998; at the time specified in paragraph
(d)(1), (d)(2), or (d)(3) of this AD, as applicable. Accomplishment
of this action constitutes terminating action for this AD.
(1) For all airplanes that have accumulated less than 26,000
total flight cycles as of the effective date of this AD: Within
10,000 flight cycles after the effective date of this AD.
(2) For all airplanes that have accumulated 26,000 or more total
flight cycles and less than 30,000 total flight cycles as of the
effective date of this AD: Within 6,000 flight cycles after the
effective date of this AD.
(3) For all airplanes that have accumulated 30,000 or more total
flight cycles as of the effective date of this AD: Within 3,000
flight cycles after the effective date of this AD.
(e) If any crack is detected during the accomplishment of
paragraph (d) of this AD, and if the service bulletin listed in
paragraph (d) of this AD specifies to contact the manufacturer for
an appropriate corrective action: Prior to further flight, repair in
accordance with a method approved by the Manager, International
Branch, ANM-116, or the LFV (or its delegated agent).
Alternative Method of Compliance
(f) 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, International Branch, ANM-116.
Operators shall submit their requests through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, International Branch, ANM-116.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
Special Flight Permits
(g) 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.
Note 4: The subject of this AD is addressed in Swedish
airworthiness directives 1-110R2, dated December 7, 1998, and 1-133,
dated October 20, 1998.
Issued in Renton, Washington, on July 9, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-18100 Filed 7-14-99; 8:45 am]
BILLING CODE 4910-13-U
