[Federal Register Volume 59, Number 21 (Tuesday, February 1, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-2179]


[[Page Unknown]]

[Federal Register: February 1, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-192-AD; Amendment 39-8813; AD 94-03-06]

 

Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Saab Model SAAB SF340A and SAAB 340B series 
airplanes. This action requires inspections to detect improper 
connections of the wire harness installation to the nacelle fire 
extinguisher, correction of any discrepancy found, and modification of 
the wiring. This amendment is prompted by a report of improperly routed 
control wiring to the nacelle fire extinguishers on a Model SAAB 340B 
series airplane. The actions specified in this AD are intended to 
prevent failure of the fire extinguishing agent to reach the correct 
engine in the event of an engine fire.

DATES: Effective on February 16, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 16, 1994.
    Comments for inclusion in the Rules Docket must be received on or 
before April 4, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 93-NM-192-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    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 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.

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: The Luftfartsverket (LFV), which is the 
airworthiness authority for Sweden, recently notified the FAA that an 
unsafe condition may exist on certain Saab Model SAAB SF340A and SAAB 
340B series airplanes. The LFV advises that improperly routed control 
wiring to the nacelle fire extinguishers was found during a ``C check'' 
inspection on a Model SAAB 340B series airplane. Further investigation 
revealed that some airplanes have an excessively long wire harness, 
which allows the possibility to incorrectly connect the wire harness to 
the nacelle fire extinguisher cartridge. When the fire extinguisher 
discharges, fire extinguishant transfers to the opposite nacelle fire 
zone if a wire harness is incorrectly routed or connected. In such a 
case, only one extinguisher, rather than two (as under normal 
conditions), is available to extinguish a fire in the nacelle fire 
zone. This condition, if not corrected, could result in failure of the 
fire extinguishing agent to reach the correct engine in the event of an 
engine fire.
    Saab has issued Service Bulletin 340-26-012, Revision 1, dated 
October 5, 1993, that describes procedures for an inspection to detect 
improper connections of the wire harness installation to the nacelle 
fire extinguisher, correction of any discrepancy found, and 
modification of the wiring. The modification involves shortening the 
wires by making a loop and securing with wax string, as necessary. The 
LFV classified this service bulletin as mandatory and issued Swedish 
Airworthiness Directive SAD No. 1-059, dated September 13, 1993, in 
order to assure the continued airworthiness of these airplanes in 
Sweden.
    This airplane model is manufactured in Sweden and is type 
certificated for operation in the United States under the provisions of 
Section 21.29 of the Federal Aviation Regulations and the applicable 
bilateral airworthiness agreement. Pursuant to this bilateral 
airworthiness agreement, the LFV has kept the FAA informed of the 
situation described above. The FAA has examined the findings of the 
LFV, reviewed all available information, and determined that AD action 
is necessary for products of this type design that are certificated for 
operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, this AD is being issued to prevent failure of the 
fire extinguishing agent to reach the correct engine in the event of an 
engine fire. This AD requires an inspection to detect improper 
connections of the wire harness installation to the nacelle fire 
extinguisher, correction of any discrepancy found, and modification of 
the wiring. The actions are required to be accomplished in accordance 
with the service bulletin described previously.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.
Comments Invited
    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD 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 93-NM-192-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a ``significant regulatory action'' 
under Executive Order 12866. It has been determined further that this 
action involves an emergency regulation under DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979). If it is determined 
that this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket. A copy of it, if filed, 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

    I. 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:

94-03-06 SAAB AIRCRAFT AB: Amendment 39-8813. Docket 93-NM-192-AD.

    Applicability: Model SAAB SF340A series airplanes, serial 
numbers 004 through 159 inclusive; and Model SAAB 340B, serial 
numbers 160 through 345 inclusive; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To preclude cross-connection of the wire harness installation to 
the engine nacelle fire extinguisher, accomplish the following:
    (a) Within 25 days after the effective date of this AD, perform 
an inspection to ensure proper connections of the wire harness 
installation to the nacelle fire extinguisher, in accordance with 
Saab Service Bulletin 340-26-012, Revision 1, dated October 5, 1993. 
Prior to further flight, correct any discrepancy found and modify 
the wiring, in accordance with the service bulletin.
    (b) Repeat the inspection specified in paragraph (a) of this AD 
immediately following any maintenance action during which both 
electric connectors to either of the fire extinguishers in the 
nacelle electrical bays are disconnected.
    (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 inspections shall be done in accordance with Saab 
Service Bulletin 340-26-012, Revision 1, dated October 5, 1993. 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.
    (f) This amendment becomes effective on February 16, 1994.

    Issued in Renton, Washington, on January 26, 1994.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-2179 Filed 1-31-94; 8:45 am]
BILLING CODE 4910-13-U