Document ID: FAA-2007-29331-0005
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Saab Model SAAB-Fairchild SF340A (SAAB/ SF340A) and SAAB 340B Airplanes
Posted Date: 2008-04-14T04:00Z

[Federal Register: April 14, 2008 (Volume 73, Number 72)]
[Rules and Regulations]               
[Page 19983-19986]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14ap08-12]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29331; Directorate Identifier 2007-NM-136-AD; 
Amendment 39-15459; AD 2008-08-07]
RIN 2120-AA64

 
Airworthiness Directives; Saab Model SAAB-Fairchild SF340A (SAAB/
SF340A) and SAAB 340B Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) originated by an aviation authority of 
another country to identify and correct an unsafe condition on an 
aviation product. The MCAI describes the unsafe condition as:

    A crack has been found in an axle adaptor during fatigue 
testing. It was found that the internal edges of the dowel holes did 
not have the correct radius and the crack had developed from the 
edge of one of the dowel holes.
    A crack in the axle adaptor can cause the axle adaptor to fail 
and ultimately lead to loss of [the] wheels and total loss of brake 
capability.

    We are issuing this AD to require actions to correct the unsafe 
condition on these products.

DATES: This AD becomes effective May 19, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of May 19, 2008.

ADDRESSES: You may examine the AD docket on the Internet at http://
www.regulations.gov or in person at the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mike Borfitz, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
227-2677; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR

[[Page 19984]]

part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on September 28, 2007 
(72 FR 55116). That NPRM proposed to correct an unsafe condition for 
the specified products. The MCAI states:

    A crack has been found in an axle adaptor during fatigue 
testing. It was found that the internal edges of the dowel holes did 
not have the correct radius and the crack had developed from the 
edge of one of the dowel holes.
    A crack in the axle adaptor can cause the axle adaptor to fail 
and ultimately lead to loss of [the] wheels and total loss of brake 
capability.

    The corrective action includes doing repetitive ultrasonic 
inspections to detect cracking in the axle adaptor; replacing the axle 
adaptor if necessary; and ultimately doing the terminating action of 
inspecting and modifying the main landing gear (MLG) shock strut and 
axle adaptors. The inspection is a crack test. The modification 
includes measuring the dowel hole, and corrective actions if necessary 
(replacing the axle adaptor, repairing the dowel hole) and, when 
accomplished, terminates the repetitive inspection requirements. You 
may obtain further information by examining the MCAI in the AD docket.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received no comments on the NPRM or on the determination of 
the cost to the public.

Clarification of Service Bulletin Revisions

    We have revised paragraph (f)(5) of the final rule to clarify the 
applicable service bulletin revisions for the parts installation.

Conclusion

    We reviewed the available data and determined that air safety and 
the public interest require adopting the AD with the change described 
previously. We determined that this change will not increase the 
economic burden on any operator or increase the scope of the AD.

Differences Between This AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have required different actions in this AD from those 
in the MCAI in order to follow our FAA policies. Any such differences 
are highlighted in a NOTE within the AD.

Costs of Compliance

    We estimate that this AD will affect about 220 products of U.S. 
registry. We also estimate that it will take about 9 work-hours per 
product to comply with the basic requirements of this AD. The average 
labor rate is $80 per work-hour. Required parts cost would be 
negligible. Where the service information lists required parts costs 
that are covered under warranty, we have assumed that there will be no 
charge for these parts. As we do not control warranty coverage for 
affected parties, some parties may incur costs higher than estimated 
here. Based on these figures, we estimate the cost of this AD to the 
U.S. operators to be $158,400, or $720 per product.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD 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.
    For the reasons discussed above, I certify this AD:
    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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains the NPRM, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (telephone (800) 647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 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. The FAA amends Sec.  39.13 by adding the following new AD:

2008-08-07 Saab Aircraft AB: Amendment 39-15459. Docket No. FAA-
2007-29331; Directorate Identifier 2007-NM-136-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective May 19, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the airplanes listed in paragraphs (c)(1) 
and (c)(2) of this AD, certificated in any category, unless equipped 
with main landing gear (MLG) shock struts modified in accordance 
with APPH Service Bulletin AIR83064-32-12 or AIR83022-32-32.
    (1) Saab Model SAAB-Fairchild SF340A (SAAB/SF340A) airplanes, 
serial numbers (S/Ns) SF340A-004 through -159.
    (2) Saab Model SAAB 340B airplanes, S/Ns 340B-160 through -459.

[[Page 19985]]

Subject

    (d) Air Transport Association (ATA) of America Code 32: Landing 
Gear.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:

    A crack has been found in an axle adaptor during fatigue 
testing. It was found that the internal edges of the dowel holes did 
not have the correct radius and the crack had developed from the 
edge of one of the dowel holes.
    A crack in the axle adaptor can cause the axle adaptor to fail 
and ultimately lead to loss of [the] wheels and total loss of brake 
capability.

    The corrective action includes doing repetitive ultrasonic 
inspections to detect cracking in the axle adaptor; replacing the 
axle adaptor if necessary; and ultimately doing the terminating 
action of inspecting and modifying the main landing gear (MLG) shock 
strut and axle adaptors. The inspection is a crack test. The 
modification includes measuring the dowel hole and corrective 
actions if necessary (replacing the axle adaptor, repairing the 
dowel hole), and, when accomplished, terminates the repetitive 
inspection requirements.

Actions and Compliance

    (f) Unless already done, do the following actions.
    (1) Within 8,000 flight cycles since the last MLG overhaul, or 
within 1,500 flight cycles, or 6 months after the effective date of 
this AD, whichever occurs latest: Inspect the MLG in accordance with 
the Accomplishment Instructions of Saab Service Bulletin 340-32-133, 
Revision 01, dated May 3, 2006. If any crack is found, before 
further flight: Replace the axle adaptor in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 340-32-133, 
Revision 01, dated May 3, 2006.
    (2) Repeat the inspection required by paragraph (f)(1) of this 
AD thereafter at intervals not to exceed 2,000 flight cycles until 
the terminating action required by paragraph (f)(3) of this AD is 
accomplished.
    (3) Within 12,000 flight cycles after the effective date of this 
AD, or at the next MLG overhaul, whichever occurs earlier: Inspect 
and modify the MLG shock strut and axle adaptors in accordance with 
the Accomplishment Instructions of APPH Service Bulletin AIR83064-
32-12, Revision 3, dated April 26, 2006; or AIR83022-32-32, Revision 
3, dated April 26, 2006; as applicable.
    (4) Actions done before the effective date of this AD in 
accordance with the service bulletins listed in paragraphs 
(f)(4)(i), (f)(4)(ii), and (f)(4)(iii) of this AD, as applicable, 
are acceptable for compliance with the corresponding actions in this 
AD.
    (i) Saab Service Bulletin 340-32-133, dated April 19, 2006.
    (ii) APPH Service Bulletin AIR83064-32-12, dated January 2006; 
Revision 1, dated January 23, 2006; and Revision 2, dated March 30, 
2006.
    (iii) APPH Service Bulletin AIR83022-32-32, dated January 2006; 
Revision 1, dated January 23, 2006; and Revision 2, dated March 30, 
2006.
    (5) As of the effective date of this AD, no person may install 
an MLG shock strut having part number (P/N) AIR83022 or AIR83064, or 
axle adaptor having P/N AIR127308, AIR390226, or AIR130238, unless 
it has been inspected and modified in accordance with APPH Service 
Bulletin AIR83022-32-32 or AIR83064-32-12, as specified in paragraph 
(f)(3), (f)(4)(ii), or (f)(4)(iii) of this AD, as applicable.

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information 
as follows: No differences.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, ANM-
116, International Branch, Transport Airplane Directorate, FAA, has 
the authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. Send information to ATTN: Mike 
Borfitz, Aerospace Engineer, International Branch, ANM-116, FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 227-2677; fax (425) 227-1149. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act, the 
Office of Management and Budget (OMB) has approved the information 
collection requirements and has assigned OMB Control Number 2120-
0056.

Related Information

    (h) Refer to MCAI EASA Airworthiness Directive 2006-0263, dated 
August 29, 2006; Saab Service Bulletin 340-32-133, Revision 01, 
dated May 3, 2006; APPH Service Bulletin AIR83064-32-12, Revision 3, 
dated April 26, 2006; and APPH Service Bulletin AIR83022-32-32, 
Revision 3, dated April 26, 2006; for related information.

Material Incorporated by Reference

    (i) You must use the service information specified in Table 1 of 
this AD to do the actions required by this AD, unless the AD 
specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact Saab 
Aircraft AB, SAAB Aircraft Product Support, S-581.88, 
Link[ouml]ping, Sweden.
    (3) You may review copies 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/cfr/ibr-
locations.html.

              Table 1.--Material Incorporated by Reference
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       Service Bulletin           Revision                Date
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APPH Service Bulletin                       3  April 26, 2006.
 AIR83022-32-32.
APPH Service Bulletin                       3  April 26, 2006.
 AIR83064-32-12.
Saab Service Bulletin 340-32-              01  May 3, 2006.
 133.
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[[Page 19986]]

    Issued in Renton, Washington, on March 31, 2008.
Dionne Palermo,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-7299 Filed 4-11-08; 8:45 am]

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