

[Federal Register: September 28, 2007 (Volume 72, Number 188)]
[Proposed Rules]               
[Page 55116-55118]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28se07-33]                         

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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]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. This proposed 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.

The proposed AD would require actions that are intended to address the 
unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by October 29, 
2007.

ADDRESSES: You may send comments by any of the following methods:
     DOT Docket Web Site: Go to http://dms.dot.gov and follow 

the instructions for sending your comments electronically.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: Room W12-140 on the ground floor of the 
West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Federal eRulemaking Portal: http://www.regulations.gov. 

Follow the instructions for submitting comments.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://dms.dot.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 this proposed AD, 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.

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:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2007-
29331; Directorate Identifier 2007-NM-136-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will 

also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued EASA 
Airworthiness Directive 2006-0263, dated August 29, 2006 (referred to 
after this as ``the MCAI''), 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.

Relevant Service Information

    Saab has issued Service Bulletin 340-32-133, Revision 01, dated May 
3, 2006. APPH Limited has issued APPH Service Bulletin AIR83064-32-12, 
Revision 3, dated April 26, 2006; and AIR83022-32-32, Revision 3, dated 
April 26, 2006.

[[Page 55117]]

The actions described in this service information are intended to 
correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

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 proposed different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
highlighted in a NOTE within the proposed AD.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 220 products of U.S. registry. We also estimate that 
it would take about 9 work-hours per product to comply with the basic 
requirements of this proposed AD. Required parts cost would be 
negligible. The average labor rate is $80 per work-hour. Where the 
service information lists required parts costs that are covered under 
warranty, we have assumed that there will be no charge for these costs. 
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 the proposed AD on 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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify 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. 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 proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

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

Saab Aircraft AB: Docket No. FAA-2007-29331; Directorate Identifier 
2007-NM-136-AD.

Comments Due Date

    (a) We must receive comments by October 29, 2007.

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.

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

[[Page 55118]]

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 AIR 83064-32-12, dated January 18, 
2006; Revision 1, dated January 23, 2006; and Revision 2, dated 
March 30, 2006.
    (iii) APPH Service Bulletin AIR83022-32-32, dated January 18, 
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 83064, or 
axle adaptor having P/N AIR127308, 390226, or AIR130238, unless it 
has been inspected and modified in accordance with APPH Service 
Bulletin AIR83022-32-32 or AIR83064-32-12.

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.

    Issued in Renton, Washington, on September 21, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-19202 Filed 9-27-07; 8:45 am]

BILLING CODE 4910-13-P
