[Federal Register Volume 64, Number 33 (Friday, February 19, 1999)]
[Rules and Regulations]
[Pages 8227-8229]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-3728]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-236-AD; Amendment 39-11042; AD 99-04-17]
RIN 2120-AA64
Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Saab Model SAAB SF340A and SAAB 340B series
airplanes, that requires inspections to detect discrepancies of the
support straps of the flaps and adjacent areas, and corrective action,
if necessary. This amendment also requires replacement of the support
straps with new straps made of steel. This amendment is prompted by
issuance of mandatory continuing airworthiness information by a foreign
civil airworthiness authority. The actions specified by this AD are
intended to prevent fatigue cracking of the support straps of the
flaps, which could result in further damage to the flap structure, and
consequently lead to reduced controllability of the airplane.
DATES: Effective March 26, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 26, 1999.
ADDRESSES: The service information referenced in this AD may be
obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Linkoping, Sweden. This information may be examined at the
Federal Aviation Administration (FAA), Transport Airplane Directorate,
Rules Docket, 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: Norman B. Martenson, 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: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Saab Model SAAB SF340A and
SAAB 340B series airplanes was published in the Federal Register on
November 7, 1997 (62 FR 60191). That action proposed to require
inspections to detect discrepancies of the support straps of the flaps
and adjacent areas; corrective action, if necessary; and replacement of
the support straps with new straps made of steel.
Actions Since Issuance of Proposal
Since the issuance of the proposal, Saab issued Service Bulletin
340-57-033, Revision 02, dated January 29, 1998. The inspection and
modification procedures described in Revision 02 are substantially
equivalent to those described in Revision 01 (which was cited in the
proposal as the appropriate source of service information for
accomplishment of the actions). The only change effected by Revision 02
is to clarify certain procedures. The final rule has been revised to
require accomplishment of the actions in accordance with either
Revision 01 or Revision 02 of the service bulletin.
[[Page 8228]]
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Support for the Proposal
One commenter supports the proposal.
Requests To Accept or Include Manufacturer's Approved Repairs in
Final Rule
One commenter, the manufacturer, requests that the proposal be
revised to accept repairs based on approval by Saab, in lieu of
approval by the FAA, in the event cracking is detected. The commenter
notes that the LFV has authorized Saab to approve such repairs. Another
commenter requests that the final rule be revised to specifically
reference or incorporate repair instructions provided by the
manufacturer. That commenter states that operators that are required to
accomplish repairs will likely incur a sizable delay or cancellation
while awaiting repair approval by the FAA.
The FAA does not concur. Specific repair instructions were not
included in the referenced service bulletin, and have not been provided
to the FAA by the manufacturer, so cannot be included in this AD.
Additionally, despite the LFV's current authorization of repair
approval by Saab, the FAA cannot delegate authority for general
approval of repairs on the FAA's behalf to Saab, because the status of
Saab's delegation by the LFV could change without notice. However, in
light of the type of repair that would be required to address the
identified unsafe condition, and in consonance with existing bilateral
airworthiness agreement with Sweden, the FAA has determined that, for
this AD, a repair approved by either the FAA or the LFV (or its
delegated agent) is acceptable for compliance with this AD. Paragraphs
(a) and (b) of the final rule have been revised accordingly.
Request To Cite Earlier Version of Service Bulletin
One commenter requests that the proposed AD be revised to refer to
the original version of Saab Service Bulletin 340-57-033, dated May 29,
1997. (Revision 01 of the service bulletin, dated August 18, 1997, was
referred to in the proposed AD as the appropriate source of service
information for accomplishment of the actions.) The commenter states
that it already has accomplished certain actions in accordance with the
original version of the service bulletin, and requests credit for this
work.
The FAA concurs. The FAA has determined that the actions described
in the original version and Revision 01 of the service bulletin are
substantially equivalent. Therefore, a NOTE has been added to the final
rule to refer to the original issue of the service bulletin as an
acceptable means of compliance with this AD. (Operators should note
that, as discussed previously, the final rule has been revised to
additionally cite Revision 02 as an appropriate source of service
information for compliance with this AD.)
Request To Revise Compliance Language
One commenter (the manufacturer) requests that the compliance
language of the proposal be revised to be consistent with the intent of
the service bulletin. The commenter requests that paragraph (a) of the
proposal be revised to identify compliance in terms of flight cycles on
each flap, rather than flight cycles on the airplane. In addition, the
commenter requests that paragraph (b) of the proposal be revised to
require accomplishment, for flaps that have accumulated 16,000 flight
cycles, at a time ``not later than either at the next scheduled
structural inspection of the flaps or within 3,000 flight cycles,
whichever occurs later.'' By contrast, the proposal specified
compliance in terms of ``the next scheduled structural inspection of
the flaps, but not later than the accumulation of 3,000 flight
cycles.''
The FAA partially concurs with the commenter's request to revise
the compliance language of the proposed AD.
The FAA does not agree that the compliance should be specified in
terms of flight cycles on the flaps. Because the FAA requires operators
to document flight cycles on each airplane, but not on individual flap
assemblies, operators may be unable to ascertain the exact number of
flight cycles on an individual flap. The final rule will retain
compliance in terms of flight cycles on the airplane.
The FAA agrees that the detailed visual inspection and replacement
should be performed at the next scheduled flap inspection or within
3,000 flight cycles, whichever occurs later. However, the FAA finds it
necessary to more precisely define the ``next scheduled flap
inspection'' interval because some U.S. operators may follow different
inspection schedules. Therefore, the FAA finds that this compliance
time should be defined as ``Prior to the accumulation of 6,000 flight
cycles after the last scheduled detailed visual inspection (if any) of
the flaps accomplished prior to the effective date of this AD'' (which
may have been accomplished in accordance with the Saab 340 Maintenance
Review Board document). Additionally, the FAA concurs that the
inspection specified by paragraph (b) of this AD is not required until
the airplane has accumulated 16,000 total flight cycles. Paragraph (b)
of the final rule has been reformatted and revised accordingly. A new
paragraph (c) has been added to the final rule to specify the
terminating action for paragraph (a) of this AD [which was specified
previously in paragraph (b) of the original NPRM].
Additional Change to Proposal
The FAA has become aware that the inspection requirement in
paragraph (b) of the proposed rule could be misinterpreted contrary to
the FAA's intent. Paragraph (b) of the final rule has further been
revised to clarify that the required inspection is a ``detailed visual
inspection'' rather than simply a ``detailed inspection.''
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes described
previously. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Cost Impact
The FAA estimates that 252 Saab Model SAAB SF340A and SAAB 340B
series airplanes of U.S. registry will be affected by this AD.
It will take approximately 30 work hours per airplane to accomplish
the required visual inspection, at an average labor rate of $60 per
work hour. Based on these figures, the cost impact on U.S. operators of
the visual inspection required by this AD is estimated to be $1,800 per
airplane.
It will take approximately 180 work hours per airplane to
accomplish the required detailed visual inspection and concurrent
replacement, at an average labor rate of $60 per work hour. Required
parts will cost approximately $4,580 per airplane. Based on these
figures, the cost impact on U.S. operators of the detailed visual
inspection and replacement required by this AD is estimated to be
$3,875,760, or $15,380 per airplane.
The cost impact figures discussed above are based on assumptions
that no
[[Page 8229]]
operator has yet accomplished any of the 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 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.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it 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:
99-04-17 Saab Aircraft AB: Amendment 39-11042. Docket 97-NM-236-AD.
Applicability: Model SAAB SF340A and SAAB 340B series airplanes,
as listed in Saab Service Bulletin 340-57-033, Revision 01, dated
August 18, 1997; 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 (e) 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 fatigue cracking of the support straps of the flaps,
which could result in further damage to the flap structure and
reduced controllability of the airplane, accomplish the following:
Note 2: Accomplishment of the inspections and replacement
specified by paragraphs (a) and (b) of this AD, in accordance with
Saab Service Bulletin 340-57-033, dated May 29, 1997, is also
considered acceptable for compliance with the requirements of those
paragraphs.
(a) Except as provided by paragraph (b) of this AD: Prior to the
accumulation of 16,000 total flight cycles, or within 1,500 flight
cycles after the effective date of this AD, whichever occurs later,
perform a visual inspection to detect discrepancies (i.e., cracking
and/or damage) of the support straps of the left- and right-hand
flaps and adjacent areas, in accordance with Saab Service Bulletin
340-57-033, Revision 01, dated August 18, 1997; or Revision 02,
dated January 29, 1998. If any discrepancy is detected, prior to
further flight, repair it in accordance with a method approved by
either the Manager, International Branch, ANM-116, FAA, Transport
Airplane Directorate, or the Luftfartsverket (LFV) (or its delegated
agent).
(b) Perform a detailed visual inspection to detect discrepancies
(i.e., cracking and/or damage) of the left- and right-hand flaps in
the area adjacent to the support straps, and replace the support
straps of the left- and right-hand flaps with new straps made of
steel; at the latest of the times specified by paragraphs (b)(1),
(b)(2), and (b)(3) of this AD; in accordance with Saab Service
Bulletin 340-57-033, Revision 01, dated August 18, 1997, or Revision
02, dated January 29, 1998. If any discrepancy is detected during
the detailed visual inspection, prior to further flight, repair it
in accordance with a method approved by either the Manager,
International Branch, ANM-116, or the LFV (or its delegated agent).
(1) Prior to the accumulation of 6,000 flight cycles after the
last scheduled detailed visual inspection (if any) of the flaps
accomplished prior to the effective date of this AD; or
(2) Within 3,000 flight cycles after the effective date of this
AD; or
(3) Prior to the accumulation of 16,000 total flight cycles.
(c) Accomplishment of the inspection and replacement specified
in paragraph (b) of this AD constitutes terminating action for the
requirements of paragraph (a) of this AD.
(d) As of the effective date of this AD, no person shall install
a flap assembly having part number 7257800-501 through -508
inclusive, -571, -572, or -851 through -858 inclusive, on any
airplane, unless that flap assembly has been modified in accordance
with Saab Service Bulletin 340-57-033, Revision 01, dated August 18,
1997, or Revision 02, dated January 29, 1998.
(e) 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, 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, 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.
(f) 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.
(g) Except as provided by paragraphs (a) and (b) of this AD, the
actions shall be done in accordance with Saab Service Bulletin 340-
57-033, Revision 01, dated August 18, 1997, or Saab Service Bulletin
340-57-033, Revision 02, dated January 29, 1998. 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 Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Linkoping, Sweden. 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.
Note 4: The subject of this AD is addressed in Swedish
airworthiness directive SAD No. 1-117, dated June 9, 1997.
(h) This amendment becomes effective on March 26, 1999.
Issued in Renton, Washington, on February 9, 1999.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-3728 Filed 2-18-99; 8:45 am]
BILLING CODE 4910-13-U
