[Federal Register Volume 71, Number 44 (Tuesday, March 7, 2006)]
[Proposed Rules]
[Pages 11349-11351]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-3227]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24075; Directorate Identifier 2005-NM-235-AD]
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: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Saab Model SAAB-Fairchild SF340A (SAAB/SF340A) and SAAB 
340B airplanes. This proposed AD would require a one-time inspection to 
see if a faulty uplock axle for the shock strut of the main landing 
gear (MLG) is installed, and replacing the uplock axle with a new 
uplock axle if necessary. This proposed AD results from a report of a 
cracked uplock axle caused by hydrogen embrittlement during the 
manufacturing process. We are proposing this AD to prevent failure of 
the uplock mechanism, which, combined with a loss of hydraulic 
pressure, could result in an uncommanded extension of the MLG.

DATES: We must receive comments on this proposed AD by April 6, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Saab Aircraft AB, SAAB Aircraft Product Support, S-581.88, 
Link[ouml]ping, Sweden, for service information identified in this 
proposed AD.

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:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2006-
24075; Directorate Identifier 2005-NM-235-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of 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 with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    The Luftfartsstyrelsen (LFS), which is the airworthiness authority 
for Sweden, notified us that an unsafe condition may exist on certain 
Saab Model SAAB-Fairchild SF340A (SAAB/SF340A) and SAAB 340B airplanes. 
The LFS advises that a cracked uplock axle for the shock strut of the 
main landing gear (MLG) has been found. The crack was caused by 
hydrogen embrittlement during the manufacturing process. The LFS 
further advises that all uplock axles produced in the same batch must 
be removed from service and scrapped. A cracked uplock axle, combined 
with a loss of hydraulic pressure, if not corrected, could result in an 
uncommanded extension of the MLG.

Relevant Service Information

    Saab has issued Saab Service Bulletin 340-32-132, dated November 3, 
2005. The service bulletin describes procedures for inspecting the 
shock strut of the MLG to see if an uplock axle with an affected serial 
number is installed, and replacing the uplock axle with a new uplock 
axle if necessary. Accomplishing the actions specified in the service 
information is intended to adequately address the unsafe condition. The 
LFS mandated the service information and issued Swedish airworthiness 
directive 1-199, dated November 9, 2005, to ensure the continued 
airworthiness of these airplanes in Sweden.
    The Saab service bulletin refers to APPH Service Bulletins 
AIR83022-32-31, Revision 1; and AIR83064-32-11, Revision 1; both dated 
October 2005; as additional sources of service

[[Page 11350]]

information for identifying uplock axles with affected serial numbers, 
and replacing the axles if necessary. The APPH service bulletins are 
attached to the Saab service bulletin.

FAA's Determination and Requirements of the Proposed AD

    These airplane models are manufactured in Sweden and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, the LFS has kept the FAA informed of 
the situation described above. We have examined the LFS's findings, 
evaluated all pertinent information, and determined that we need to 
issue an AD for airplanes of this type design that are certificated for 
operation in the United States.
    Therefore, we are proposing this AD, which would require 
accomplishing the actions specified in the service information 
described previously.

Costs of Compliance

    This proposed AD would affect about 248 airplanes of U.S. registry. 
The proposed inspection would take about 1 work hour per airplane, at 
an average labor rate of $65 per work hour. Based on these figures, the 
estimated cost of the proposed AD for U.S. operators is $16,120, or $65 
per airplane.

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 have 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 that the 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. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Saab Aircraft AB: Docket No. FAA-2006-24075; Directorate Identifier 
2005-NM-235-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by April 6, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to SAAB Model SAAB-Fairchild SF340A (SAAB/
SF340A) and SAAB 340B airplanes, certificated in any category; 
serial numbers SAAB SF340A -004 through -159 inclusive, and SAAB 
340B -160 through -459 inclusive.

Unsafe Condition

    (d) This AD results from a report of a cracked uplock axle of 
the main landing gear (MLG) shock strut, caused by hydrogen 
embrittlement during the manufacturing process. We are proposing 
this AD to prevent failure of the uplock mechanism, which, combined 
with a loss of hydraulic pressure, could result in an uncommanded 
extension of the MLG.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Inspection To Determine Part Number

    (f) Within 6 months after the effective date of this AD, inspect 
the uplock axle of the MLG shock strut to determine whether an 
affected serial number (S/N) is installed. A review of airplane 
maintenance records is acceptable in lieu of this inspection if the 
S/N of the uplock axle can be conclusively determined from that 
review. Do the inspection in accordance with the Accomplishment 
Instructions of Saab Service Bulletin 340-32-132, dated November 3, 
2005.

    Note 1: The Saab service bulletin refers to APPH Service 
Bulletins AIR83022-32-31, Revision 1; and AIR83064-32-11, Revision 
1; both dated October 2005; as additional sources of service 
information for identifying uplock axles with affected serial 
numbers, and replacing the axles if necessary. The APPH service 
bulletins are attached to the Saab service bulletin.

Corrective Action

    (g) Before further flight after accomplishing the inspection 
required by paragraph (f) of this AD: Replace with a new uplock axle 
any uplock axle with an affected S/N identified by the inspection in 
paragraph (f) of this AD. Do all actions in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 340-32-132, 
dated November 3, 2005.

Parts Installation

    (h) As of the effective date of this AD, no person may install 
an uplock axle on any airplane if it has an affected S/N identified 
in accordance with paragraph (f) of this AD.

No Reporting Requirement

    (i) Although the Accomplishment Instructions of Saab Service 
Bulletin 340-32-132, dated November 3, 2005, specify to send a 
report with the serial number of replaced uplock axles to APPH Ltd., 
this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, International Branch, ANM-116, Transport 
Airplane Directorate, FAA, has the authority to approve AMOCs for 
this AD, if requested in accordance with the procedures found in 14 
CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

Related Information

    (k) Swedish airworthiness directive 1-199, dated November 9, 
2005, also addresses the subject of this AD.


[[Page 11351]]


    Issued in Renton, Washington, on February 22, 2006.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-3227 Filed 3-6-06; 8:45 am]
BILLING CODE 4910-13-P