[Federal Register Volume 59, Number 9 (Thursday, January 13, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-831]


[[Page Unknown]]

[Federal Register: January 13, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-137-AD; Amendment 39-8778; AD 93-25-14]

 

Airworthiness Directives; SAAB-Scania Model 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-Scania Model SF340A and SAAB 340B series 
airplanes, that requires replacement of the left- and right-hand AC 
generator control relays with new relays at the generator control 
positions. This amendment is prompted by reports that in-service AC 
generator control relays, specifically used for generator transfer 
functions, have failed where the main contacts arced. The actions 
specified by this AD are intended to prevent loss of AC electrical 
power, and local area damage that may lead to further electrical 
failures and smoke in the cockpit.

DATES: Effective February 14, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 14, 1994.

ADDRESSES: The service information referenced in this AD may be 
obtained from SAAB-Scania AB, SAAB Aircraft Support Product, 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: Mark Quam, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 
227-2145; fax (206) 227-1320.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an airworthiness directive (AD) that is 
applicable to certain SAAB-Scania Model SF340A and SAAB 340B series 
airplanes was published in the Federal Register on September 14, 1993 
(58 FR 48010). That action proposed to require replacement of the left- 
and right-hand AC generator control relays, part number (P/N) SM15CXD1, 
with new relays, P/N SM15CXD4, at the generator control positions (7XA/
8XA).
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received.
    The commenter supports the proposed rule.
    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.
    The FAA estimates that 200 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 2.5 work hours per 
airplane to accomplish the required actions, and that the average labor 
rate is $55 per work hour. Required parts will be supplied by the 
manufacturer at no cost to the operators. Based on these figures, the 
total cost impact of the AD on U.S. operators is estimated to be 
$27,500, or $137.50 per airplane. This total cost figure assumes that 
no operator has yet accomplished the requirements of this AD.
    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 14 CFR part 
39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

93-25-14 SAAB-Scania: Amendment 39-8778. Docket 93-NM-137-AD.

    Applicability: Model SAAB SF340A series airplanes, serial 
numbers 004 through 159 inclusive; and Model SAAB 340B series 
airplanes, serial numbers 160 through 325 inclusive; certificated in 
any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent loss of AC electrical power, and local area damage 
that may lead to further electrical failures and smoke in the 
cockpit, accomplish the following:
    (a) Within 6 months after the effective date of this AD, replace 
the left- and right-hand AC generator control relays, part number 
(P/N) SM15CXD1, with new relays, P/N SM15CXD4, at generator control 
positions 7XA and 8XA, in accordance with SAAB 340 Service Bulletin 
SAAB 340-24-022, dated October 21, 1992.
    (b) As of the effective date of this AD, no person shall install 
an AC generator control relay, P/N SM15CXD1, at generator control 
positions 7XA or 8XA on any airplane.
    (c) 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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (d) Special flight permits may be issued in accordance with FAR 
21.197 and 21.199 to operate the airplane to a location where the 
requirements of this AD can be accomplished.
    (e) The replacement shall be done in accordance with SAAB 340 
Service Bulletin SAAB 340-24-022, dated October 21, 1992. 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-Scania AB, SAAB Aircraft 
Support Product, 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.
    (f) This amendment becomes effective on February 14, 1994.

    Issued in Renton, Washington, on December 21, 1993.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-831 Filed 1-12-94; 8:45 am]
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