AD 2004-11-02

final rule

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

AD Number
2004-11-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. 2003-NM-18-AD
FR Citation
69 FR 31000

Applicability

TypeManufacturerModelDetails
aircraft Saab AB, Saab Aerosystems SAAB 340B Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B Series Airplanes
aircraft Saab AB, Saab Aerosystems 340A (SAAB SF340A) Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B Series Airplanes

Unsafe Condition

Fatigue cracks in the outer flange of the nacelle frame, which could result in reduced structural integrity of the nacelle supporting structure.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Perform detailed, ultrasonic, eddy current, and dye penetrant inspections of the internal and external structure of the nacelles for cracks, deformations, or other damage, in accordance with Saab Service Bulletin 340-54-043.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Required as indicated, unless accomplished previously.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Saab 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.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

This amendment adopts a new airworthiness directive (AD), applicable to certain Saab Model SAAB SF340A and Model SAAB 340B series airplanes, that requires inspections of the internal and external 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.

Document Text

Show stored source text (verify against official source)
[Federal Register Volume 69, Number 106 (Wednesday, June 2, 2004)]
[Rules and Regulations]
[Pages 31000-31002]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 04-11958]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-18-AD; Amendment 39-13647; AD 2004-11-02]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD),

[[Page 31001]]

applicable to certain Saab Model SAAB SF340A and Model SAAB 340B series 
airplanes, that requires inspections of the internal and external 
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: Effective July 7, 2004.
    The incorporation by reference of a certain publication listed in 
the regulations is approved by the Director of the Federal Register as 
of July 7, 2004.

ADDRESSES: The service information referenced in this AD 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 
Federal Aviation Administration (FAA), Transport Airplane Directorate, 
Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information on 
the availability of this material at NARA, call (202) 741-6030, or go 
to: <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.

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: 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 
Model SAAB 340B series airplanes was published in the Federal Register 
on February 6, 2004 (69 FR 5778). That action proposed to require 
inspections of the internal structure of the nacelles for cracks, 
deformations, or other damage, and corrective actions if necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. The FAA has duly considered the 
comments received.

Request To Withdraw Proposed AD

    One commenter requests that the proposed AD be withdrawn. The 
commenter cites a lack of information to justify rulemaking and 
questions whether the need for the proposed AD was substantiated by a 
review of service difficulty report (SDR) data. The commenter states 
that there is nothing in the proposed AD to indicate that the current 
maintenance program is inadequate for finding and addressing the 
cracks, deformation, or other damage that are the subject of the 
proposed AD. The commenter specifically requests that we contact the 
Luftfartsverket (LFV), which is the airworthiness authority for Sweden, 
to determine whether the findings that prompted this action can be 
distinguished from findings during normal maintenance. The commenter 
also points to the lack of specific repair information in the proposed 
AD and relevant service information, and the commenter does not support 
the issuance of any AD without at least general guidance on the 
disposition of repairs as a result of findings.
    We do not concur with the commenter's request to withdraw this AD. 
The service bulletin and the parallel Swedish airworthiness directive 
specify that the subject area is a ``blind'' area that is difficult to 
access and inspect. Consequently, discrepancies in the subject area may 
not be found during normal maintenance. We do review SDR data and, when 
necessary, we discuss significant issues with the cognizant 
airworthiness authority and the airplane manufacturer to ensure that 
safety issues are addressed. No change to the final rule is necessary 
in this regard.

Request To Revise Description of Structure Subject to Inspections

    One commenter, the airplane manufacturer, requests that we revise 
the proposed AD to specify that the structure subject to the 
inspections is the internal and external structure of the nacelles. The 
commenter points out that, while the proposed AD specifies inspections 
of ``internal structure,'' the inspection area includes the skin of the 
nacelles, which is external structure.
    We concur that the commenter's description more accurately depicts 
the actions defined in the service bulletin and have revised the 
Summary section and paragraph (a) of this AD accordingly. (The 
Explanation of Relevant Service Information section of the proposed AD 
is not restated in this final rule, so no change is possible to that 
section.) We find that this change does not increase the scope of the 
proposed AD because we did not state in the proposed AD that we 
intended to differ from the referenced service bulletin in this regard.

Request To Reference Additional Inspection Methods

    The same commenter requests that we revise the proposed AD to 
clarify that an eddy current or dye penetrant inspection may be 
necessary, as specified in the Accomplishment Instructions of the 
referenced service bulletin. The proposed AD specifies only detailed 
and ultrasonic inspections.
    We concur with the commenter's request and have revised paragraph 
(a) of this AD to specify inspections using detailed, ultrasonic, eddy 
current, and dye penetrant methods, as applicable. (The Explanation of 
Relevant Service Information section of the proposed AD is not restated 
in this final rule, so no change is possible to that section.) We find 
that this change does not increase the scope of the proposed AD because 
we did not state in the proposed AD that we intended to differ from the 
referenced service bulletin in the type of inspection methods that may 
be necessary.

Request To Clarify Action if Attachment Angle Is Damaged

    The same commenter requests that we revise the proposed AD to 
clarify that, if discrepancies are found, the fire deck attachment 
angle cannot be repaired but must be replaced. The commenter notes that 
the attachment angle may be replaced per the Accomplishment 
Instructions of the referenced service bulletin, but other cracks, 
deformation, or damage must be repaired per data provided by the 
manufacturer.
    We acknowledge the commenter's concerns and agree that some 
clarification is necessary. As specified in the Explanation of Relevant 
Service Information section of the proposed AD, corrective actions 
include replacement of the fire deck attachment angle with a new angle, 
and repair of cracks, deformation, and damage. We have revised 
paragraph (d) of this AD to clarify these corrective actions.
    With regard to the commenter's request to specify that repairs must 
be done per data provided by the manufacturer, we explain in the 
proposed AD that, where the service bulletin specifies that operators 
may contact the manufacturer for disposition of repairs, this AD would 
require operators to repair per a method approved by the FAA or the LFV 
(or its delegated agent). No change to the AD is necessary in this 
regard.

Conclusion

    After careful review of the available data, including the comments 
noted

[[Page 31002]]

above, we have determined that air safety and the public interest 
require the adoption of the rule with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Cost Impact

    We estimate that 224 airplanes of U.S. registry will be affected by 
this AD, that it will take approximately 4 work hours per airplane to 
accomplish the required inspection, and that the average labor rate is 
$65 per work hour. Based on these figures, the cost impact of this 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 requirements of this AD 
action, and that no operator would accomplish those actions in the 
future if this 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 adopted herein will 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 final rule does not have federalism 
implications under Executive Order 13132.
    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

0
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

0
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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2004-11-02 Saab Aircraft AB: Amendment 39-13647. 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:

Inspections

    (a) Perform detailed, ultrasonic, eddy current, and dye 
penetrant inspections; as applicable; of the internal and external 
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 inspections at 
the applicable times specified by paragraph 1.D, ``Compliance,'' of 
the service bulletin, except as required by paragraphs (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, replace the fire deck attachment angle with a new angle, and 
accomplish repairs, as applicable, in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 340-54-043, 
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.

Incorporation by Reference

    (f) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Saab Service Bulletin 340-54-043, dated 
December 18, 2002. 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 National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call (202) 741-6030, or go 
to: <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.

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

Effective Date

    (g) This amendment becomes effective on July 7, 2004.

    Issued in Renton, Washington, on May 18, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-11958 Filed 6-1-04; 8:45 am]
BILLING CODE 4910-13-P

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