AD 2004-11-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| 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
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[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.
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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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