[Federal Register Volume 69, Number 25 (Friday, February 6, 2004)]
[Proposed Rules]
[Pages 5778-5780]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-2475]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-18-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Saab Model SAAB SF340A and 
Model SAAB 340B series airplanes. This proposal would require 
inspections of the internal structure of the nacelles for cracks, 
deformations, or other damage, and corrective actions if necessary. 
This action is necessary to prevent fatigue cracks in the outer flange 
of the nacelle frame, which could result in reduced structural 
integrity of the nacelle supporting structure. This action is intended 
to address the identified unsafe condition.

DATES: Comments must be received by March 8, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-18-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2003-NM-18-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Link[ouml]ping, Sweden. This information may be examined at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Dan Rodina, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2125; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, 
discuss a request to change the compliance time and a request to change 
the service bulletin reference as two separate issues.
     For each issue, state what specific change to 
the proposed AD is being requested.
     Include justification (e.g., reasons or data) 
for each request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2003-NM-18-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2003-NM-18-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Luftfartsverket (LFV), which is the airworthiness authority for 
Sweden, notified the FAA that an unsafe condition may exist on certain 
Saab Model SAAB SF340A and SAAB 340B series airplanes. The LFV advises 
that it has received reports of fatigue cracks in the outer flange of 
nacelle frame station 203 between water line (WL) 92 to WL96. This 
condition, if not detected and corrected in a timely manner, could lead 
to reduced structural integrity of the nacelle supporting structure.

Explanation of Relevant Service Information

    Saab has issued Service Bulletin 340-54-043, dated December 18, 
2002, which describes procedures for detailed and ultrasonic 
inspections of the internal structure of the nacelles for cracks, 
deformations and damage, and corrective actions if necessary. The 
corrective actions include replacement of the firedeck attachment angle 
with a new angle and repair of cracks, deformation, and damage. This 
service bulletin recommends compliance times for the inspections at the 
following approximate flight cycle levels:
    1. For airplanes with less than 20,000 total flight cycles, 
accomplish before 24,000 total flight cycles; and
    2. For airplanes with 20,000 total flight cycles or more, 
accomplish within 2,000 to 4,000 flight cycles after the service 
bulletin's release date, depending on the airplane's total flight 
cycles.
    Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the

[[Page 5779]]

identified unsafe condition. The LFV classified this service bulletin 
as mandatory and issued Swedish airworthiness directive No 1-176, dated 
December 20, 2002, in order to assure the continued airworthiness of 
these airplanes in Sweden.

FAA's Conclusions

    These airplane models are manufactured in Sweden and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) 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.

Explanation of Requirements of Proposed Rule

    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, the proposed AD would require accomplishment of 
the actions specified in the service bulletin described previously, 
except as discussed below.

Differences Between Proposed Rule and Service Bulletin

    Although the service bulletin specifies that operators may contact 
the manufacturer for disposition of certain repairs, this proposal 
would require operators to repair per a method approved by either the 
FAA or LFV (or its delegated agent). In light of the type of repair 
that would be required to address the unsafe condition, and consistent 
with existing bilateral airworthiness agreements, we have determined 
that, for this proposed AD, a repair approved by either the FAA or LFV 
would be acceptable for compliance with this proposed AD.

Clarification of Compliance Times

    For compliance times, the service bulletin specifies ``accumulated 
flights'' and ``flights''. However, for these compliance times, 
paragraph (c) of this proposed AD specifies ``total flight cycles'' and 
``flight cycles''. This decision is based on our determination that 
``accumulated flights'' and ``flights'' may be interpreted differently 
by different operators. We find that our proposed terminology is 
generally understood within the industry and records will always exist 
that establish these cycles with certainty.

Cost Impact

    The FAA estimates that 224 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 4 work 
hours per airplane to accomplish the proposed inspection, and that the 
average labor rate is $65 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$58,240, or $260 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

Saab Aircraft AB: Docket 2003-NM-18-AD.

    Applicability: Model SAAB SF340A series airplanes with serial 
numbers 004 through 159 inclusive, and Model SAAB 340B series 
airplanes with serial numbers 160 through 459 inclusive, 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue cracks in the outer flange of the nacelle 
frame, which could result in reduced structural integrity of the 
nacelle supporting structure, accomplish the following:

Inspection

    (a) Perform detailed and ultrasonic inspections, as applicable, 
of the internal structure of the nacelles for cracks, deformations, 
or other damage, in accordance with the Accomplishment Instructions 
of Saab Service Bulletin 340-54-043, dated December 18, 2002. Do the 
inspection at the applicable time specified by paragraph 1.D, 
``Compliance'', of the service bulletin, except as required by 
paragraph (b) and (c) of this AD.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

    (b) Where the service bulletin specified in paragraph (a) of 
this AD specifies a compliance time relative to the release date of 
the service bulletin, this AD requires compliance following the 
effective date of this AD.
    (c) Where the service bulletin specified in paragraph (a) of 
this AD uses ``accumulated flights'' and ``flights'' for compliance 
times, this AD requires operators to use ``total flight cycles'' and 
``flight cycles''.

Repair

    (d) If any crack, deformation, or damage is found during any 
inspection required by paragraph (a) of this AD, before further 
flight, repair and replace the firedeck attachment angle with a new 
angle, as applicable, in accordance with the Accomplishment 
Instructions of Saab Service Bulletin 340-54-

[[Page 5780]]

043, dated December 18, 2002. Where the service bulletin specifies 
contacting the manufacturer for disposition of repairs, before 
further flight, repair per a method approved by the Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate; 
or the Luftfartsvarket (or its delegated agent).

Alternative Methods of Compliance

    (e) In accordance with 14 CFR 39.19, the Manager, International 
Branch, ANM-116, FAA, is authorized to approve alternative methods 
of compliance with this AD.

    Note 2: The subject of this AD is addressed in Swedish 
airworthiness directive No 1-176, dated December 20, 2002.


    Issued in Renton, Washington, on January 29, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-2475 Filed 2-5-04; 8:45 am]
BILLING CODE 4910-13-P