[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