Federal Aviation Administration, DOT.
This amendment adopts a new airworthiness directive (AD), Start Printed Page 31001applicable 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.
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.
The service information referenced in this AD may be obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-581.88, Linköping, 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: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.Start Further Info
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.End Further Info End Preamble Start Supplemental 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.
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One commenter requests that the proposed AD be withdrawn.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.
After careful review of the available data, including the comments noted Start Printed Page 31002above, 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.
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.
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.Start List of Subjects
List of Subjects in 14 CFR Part 39
- Air transportation
- Aviation safety
- Incorporation by reference
Adoption of the AmendmentStart Amendment Part
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:End Amendment Part Start Part
PART 39—AIRWORTHINESS DIRECTIVESEnd Part Start Amendment Part
1. The authority citation for part 39 continues to read as follows:End Amendment Part
2. Section 39.13 is amended by adding the following new airworthiness directive:End Amendment Part
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:
(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.
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.”
(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: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
The subject of this AD is addressed in Swedish airworthiness directive No. 1-176, dated December 20, 2002.
(g) This amendment becomes effective on July 7, 2004.Start Signature
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]
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