AD Amdt-39-10778

[Federal Register Volume 63, Number 184 (Wednesday, September 23, 1998)]
[Rules and Regulations]
[Pages 50753-50755]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-25027]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-100-AD; Amendment 39-10778; AD 98-20-11]
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 repetitive detailed visual inspections of the 
windshield wiper assembly for discrepant conditions, and corrective 
actions, if necessary. 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 failure of the windshield wiper assembly, which could result 
in loss of visibility; or damage to the propeller(s), possible 
penetration of the fuselage skin, and consequent depressurization of 
the airplane.

DATES: Effective October 28, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 28, 1998.

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, 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: 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 
April 21, 1998 (63 FR 19686). That action proposed to require 
repetitive, detailed visual inspections of the windshield wiper 
assembly for discrepant conditions, and corrective actions, if 
necessary.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter opposes the proposed rule. The commenter states that 
the Saab Maintenance Review Board (MRB) report covers the items 
addressed by the proposal during routine line checks. The commenter 
believes such compliance is more than sufficient to address the unsafe 
condition.
    The FAA does not agree with the remarks of this commenter. The FAA 
finds that actions performed during routine line checks are not 
detailed enough to detect the type of defects (i.e., corrosion; 
excessive wear; missing, loose, or broken parts; improper alignment; 
and insecure attachment of the windshield wiper assembly) addressed in 
this AD. This is further evidenced by the fact that failures have 
occurred in service even though the routine line checks referenced by 
the commenter were included in the current MRB report. The FAA finds 
that no change to the final rule is necessary in this regard.
    The manufacturer requests that the repetitive inspection interval 
be increased from 1,000 to 4,000 flight hours. The commenter states 
that the proposed interval is too conservative, even though the time 
necessary to perform the inspection is less than one work hour. The 
commenter bases its remarks on the fact that the SAAB 340 fleet has 
accumulated 6,110,000 flight hours as of the end of December 1997 with 
two known incidents. The commenter submits data that use vendor figures 
regarding proven capability of the wiper system, and estimated hours of 
usage of the wiper system. Based on that data, the commenter concludes 
that the interval recommended for the general visual inspection in the 
existing MRB task is a safe interval.
    The FAA concurs. The FAA finds that the data submitted by the 
commenter demonstrate that a repetitive inspection interval of 4,000 
flight hours is sufficient to address the unsafe condition addressed by 
this AD. The final rule has been revised accordingly.
    The manufacturer also requests that the proposed rule be revised to 
specify that repairs should be accomplished in accordance with Saab 
Service Bulletin 340-30-081 (which is referenced in the proposal as the 
appropriate source of service information for accomplishment of the 
inspections) and with reference to the Component Maintenance Manual.
    The FAA concurs with the commenter's request. The Saab service 
bulletin includes an attachment (Rosemount Aerospace, Inc., Service 
Bulletin 2314M-30-17, Revision 1, dated September 14, 1997); paragraph 
II.B. of this attachment describes procedures for repair or replacement 
of the windshield wiper arm assembly. The attachment also specifies 
certain sections of the Component Maintenance Manual as a source of 
additional service information. The FAA has determined that the 
procedures specified in the attachment should be referenced in this 
final rule for accomplishment of the repair, and has revised the AD 
accordingly.

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

[[Page 50754]]

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 254 Saab Model SAAB SF340A and SAAB 340B 
series airplanes of U.S. registry will be affected by this AD, that it 
will take approximately 1 work hour per airplane to accomplish the 
required actions, and that the average labor rate is $60 per work hour. 
Based on these figures, the cost impact of the AD on U.S. operators is 
estimated to be $15,240, or $60 per airplane, per inspection cycle.
    The cost impact figure discussed above is based on assumptions that 
no 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:

98-20-11  SAAB Aircraft AB (Formerly SAAB Fairchild): Amendment 39-
10778. Docket 98-NM-100-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 399 
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 (b) 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 windshield wiper assembly, which could 
result in loss of visibility; or damage to the propeller(s), 
possible penetration of the fuselage skin, and consequent 
depressurization of the airplane, accomplish the following:
    (a) Prior to the accumulation of 4,000 total flight hours, or 
within 3 months after the effective date of this AD, whichever 
occurs later, perform a detailed visual inspection of the windshield 
wiper assembly for discrepancies (corrosion; excessive wear; 
missing, loose, or broken parts; improper alignment; and insecure 
attachment), in accordance with Saab Service Bulletin 340-30-081, 
dated November 14, 1997, including Attachment 1, Revision 1, dated 
September 14, 1997.
    (1) If no discrepancy is detected during the inspection, repeat 
the inspection thereafter at intervals not to exceed 4,000 flight 
hours.
    (2) If any discrepancy is detected during any inspection, prior 
to further flight, replace the windshield wiper assembly with a new 
or serviceable windshield wiper assembly, or repair in accordance 
with Saab Service Bulletin 340-30-081, dated November 14, 1997, 
including Attachment 1, Revision 1, dated September 14, 1997. Repeat 
the detailed visual inspection thereafter at intervals not to exceed 
4,000 flight hours.
    (b) 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 request 
through an appropriate FAA Principal Maintenance Inspector, who may 
add comments and then send it to the Manager, International Branch, 
ANM-116.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (c) Special flight permits may be issued in accordance with 
Secs. 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.
    (d) The actions shall be done in accordance with Saab Service 
Bulletin 340-30-081, dated November 14, 1997, including Attachment 
1, Revision 1, dated September 14, 1997. The service bulletin 
contains the following list of effective pages:

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                                                            Revision level shown on
                        Page No.                                     page                 Date shown on page
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1-4.....................................................  Original..................  Nov. 14, 1997.
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                                                   ATTACHMENT 1
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1-4.....................................................  1.........................  Sept. 14, 1997.
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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 3: The subject of this AD is addressed in Swedish 
airworthiness directive 1-115R1, dated November 17, 1997.


[[Page 50755]]


    (e) This amendment becomes effective on October 28, 1998.

    Issued in Renton, Washington, on September 14, 1998.
Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-25027 Filed 9-22-98; 8:45 am]
BILLING CODE 4910-13-U