Document ID: FAA-2009-0134-0004
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Saab AB, Saab Aerosystems Model SAAB 340A (SAAB/SF340A) and SAAB 340B Airplanes
Posted Date: 2009-08-12T04:00Z

[Federal Register: August 12, 2009 (Volume 74, Number 154)]
[Proposed Rules]               
[Page 40527-40529]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr12au09-20]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0134; Directorate Identifier 2008-NM-162-AD]
RIN 2120-AA64

 
Airworthiness Directives; Saab AB, Saab Aerosystems Model SAAB 
340A (SAAB/SF340A) and SAAB 340B Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: We are revising an earlier NPRM for the products listed above. 
This action revises the earlier NPRM by expanding the scope. 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:

    During 2008, two cases of main hydraulic accumulator failure 
were reported, one of which was caused by corrosion. Investigation 
has shown that a severe failure can occur to any of the four 
hydraulic accumulators which are installed in the hydraulic 
compartment. Either one of the two end parts on the accumulator may 
depart from the pressure vessel due to corrosion. This condition, if 
not corrected, is likely to degrade the functionality of the 
hydraulic system, possibly resulting in degradation or total loss of 
control of the landing gear, flap actuation and brakes. A severe 
failure during flight may even result in debris penetrating and 
exiting the fuselage outer skin. When such a failure occurs while 
the aeroplane is on the ground, as in the two reported cases, this 
may cause severe damage to the fuselage and result in injuries to 
persons nearby.

* * * * *
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 September 8, 
2009.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New 
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Saab Aircraft AB, SAAB Aerosystems, SE-581 88, Link[ouml]ping, Sweden; 
telephone +46 13 18 5591; fax +46 13 18 4874; e-mail 
saab2000.techsupport@saabgroup.com; Internet http://www.saabgroup.com. 
You may review copies of the referenced service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington. For information on the availability of this material at the 
FAA, call 425-227-1221 or 425-227-1152.

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 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: Shahram Daneshmandi, Aerospace 
Engineer, International Branch, ANM-116, Transport Airplane 
Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; 
telephone (425) 227-1112; 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-2009-0134; 
Directorate Identifier 2008-NM-162-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://
www.regulations.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

    We proposed to amend 14 CFR part 39 with an earlier NPRM for the 
specified products, which was published in the Federal Register on 
February 18, 2009 (74 FR 7568). That earlier NPRM proposed to require 
actions intended to address the unsafe condition for the products 
listed above.
    Since that NPRM was issued, there was another report of main 
hydraulic accumulator failure, which occurred during final approach. 
The airplane was able to land safely, and there were no injuries 
reported. We have determined that it is necessary to reduce the 
compliance time specified in the NPRM for replacing the hydraulic 
accumulator from 24 to 12 months.
    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued EASA 
Airworthiness Directive 2008-0146R1, dated April 16, 2009 (referred to 
after this as ``the MCAI''), to correct an unsafe condition for the 
specified products. The revised MCAI states:

    During 2008, two cases of main hydraulic accumulator failure 
were reported, one of which was caused by corrosion. Investigation 
has shown that a severe failure can occur to any of the four 
hydraulic accumulators which are installed in the hydraulic 
compartment. Either one of the two end parts on the accumulator may 
depart from the pressure vessel due to corrosion. This condition, if 
not corrected, is likely to degrade the functionality of the 
hydraulic system, possibly resulting in degradation or total loss of 
control of the landing gear, flap actuation and brakes. A severe 
failure during flight may even result in debris penetrating and 
exiting the fuselage outer skin. When such a failure occurs while 
the aeroplane is

[[Page 40528]]

on the ground, as in the two reported cases, this may cause severe 
damage to the fuselage and result in injuries to persons nearby.
    Since [EASA] AD 2008-0146 was issued, one more case of main 
hydraulic accumulator failure has been reported, which occurred in 
flight during final approach. The aeroplane was able to land safely 
and there were no injuries reported on the aeroplane or on the 
ground.
    To address and correct this unsafe condition, a modified 
hydraulic accumulator has been developed, which is sealed between 
the barrel and the screw cap and between the screw cap and the end 
cap.
    For the reasons described above, this EASA AD requires the 
replacement of the affected hydraulic accumulators P/N (part number) 
08 8423 001 1 and P/N 08 8423 030 1, as identified in Saab SB 
(Service Bulletin) 340-29-023, with a modified hydraulic 
accumulator.
    This AD is revised to indicate that the accomplishment of SAAB 
SB 340-29-024 is another acceptable method to correct the unsafe 
condition.

You may obtain further information by examining the MCAI in the AD 
docket.

Relevant Service Information

    Saab has issued Service Bulletins 340-29-023 and 340-29-024, both 
Revision 01, both dated April 3, 2009. The actions described in this 
service information are intended to correct the unsafe condition 
identified in the MCAI.

Comments

    We have considered the following comments received on the earlier 
NPRM.

Request To Reduce Compliance Time

    Tactair Fluid Controls Inc. recommends that we reduce the 
compliance time specified in the NPRM for replacing the hydraulic 
accumulator from 24 to 12 months. Tactair states that the 24-month 
compliance time is too long given the age of the fleet of potentially 
affected airplanes. Tactair adds that shortening the compliance time to 
12 months would provide an additional margin of safety.
    We agree that the compliance time for replacing the hydraulic 
accumulator should be reduced to 12 months because of the recent 
incident of another failure of the hydraulic accumulator. We have 
determined that a compliance time of within 12 months after the 
effective date of the AD is appropriate and will ensure an acceptable 
level of safety. The manufacturer and EASA agree with this reduction in 
compliance time. We have changed paragraphs (f)(1), (f)(2), and (f)(3) 
of this AD accordingly.

Request To Expand Applicability

    Tactair asks that the applicability specified in the NPRM be 
expanded to add Model SAAB 2000 airplanes. Tactair states that Model 
SAAB 2000 airplanes contain hydraulic accumulators with the same part 
numbers specified in the applicability of the NPRM.
    We acknowledge the commenter's concern; however, we do not agree 
that Model SAAB 2000 airplanes should be added to this supplemental 
NPRM. EASA has determined that hydraulic accumulators with the same 
part numbers could be installed on Model SAAB 2000 airplanes; however, 
there have been no incidents on that model, and we consider the fleet 
safety risk to be lower for that model. The manufacturer has confirmed 
that service information with replacement procedures for Model SAAB 
2000 airplanes will not be issued for several months. We will consider 
additional rulemaking once service information for the Model SAAB 2000 
airplanes is developed and available. To delay issuing this 
supplemental NPRM would be inappropriate, since we have identified 
recent incidents on the affected models and have determined that the 
replacements must be done to ensure continued safety.

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.
    Certain changes described above expand the scope of the earlier 
NPRM. As a result, we have determined that it is necessary to reopen 
the comment period to provide additional opportunity for the public to 
comment on this proposed 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 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 111 products of U.S. registry. We also estimate that it 
would take 8 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $80 per 
work-hour. Required parts would cost $8,800 per product. 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 $1,047,840, or $9,440 or 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;

[[Page 40529]]

    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, Incorporation by 
reference, 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 AB, SAAB Aerosystems: Docket No. FAA-2009-0134; Directorate 
Identifier 2008-NM-162-AD.

Comments Due Date

    (a) We must receive comments by September 8, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Saab AB, Saab Aerosystems Model SAAB 340A 
(SAAB/SF340A) and SAAB 340B airplanes, all serial numbers, 
certificated in any category; on which hydraulic accumulators with 
part number (P/N) 08 8423 001 1 or P/N 08 8423 030 1 are installed, 
except accumulators with serial numbers listed in paragraph 3.B. of 
Saab Service Bulletin 340-29-023, Revision 01, dated April 3, 2009.

Subject

    (d) Air Transport Association (ATA) of America Code 29: 
Hydraulic power.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:
    During 2008, two cases of main hydraulic accumulator failure 
were reported, one of which was caused by corrosion. Investigation 
has shown that a severe failure can occur to any of the four 
hydraulic accumulators which are installed in the hydraulic 
compartment. Either one of the two end parts on the accumulator may 
depart from the pressure vessel due to corrosion. This condition, if 
not corrected, is likely to degrade the functionality of the 
hydraulic system, possibly resulting in degradation or total loss of 
control of the landing gear, flap actuation and brakes. A severe 
failure during flight may even result in debris penetrating and 
exiting the fuselage outer skin. When such a failure occurs while 
the aeroplane is on the ground, as in the two reported cases, this 
may cause severe damage to the fuselage and result in injuries to 
persons nearby.
    Since AD 2008-0146 was issued, one more case of main hydraulic 
accumulator failure has been reported, which occurred in flight 
during final approach. The aeroplane was able to land safely and 
there were no injuries reported on the aeroplane or on the ground.
    To address and correct this unsafe condition, a modified 
hydraulic accumulator has been developed, which is sealed between 
the barrel and the screw cap and between the screw cap and the end 
cap.
    For the reasons described above, this EASA AD requires the 
replacement of the affected hydraulic accumulators P/N (part number) 
08 8423 001 1 and P/N 08 8423 030 1, as identified in Saab SB 
(Service Bulletin) 340-29-023, with a modified hydraulic 
accumulator.
    This AD is revised to indicate that the accomplishment of SAAB 
SB 340-29-024 is another acceptable method to correct the unsafe 
condition.

Actions and Compliance

    (f) Unless already done, replace the hydraulic accumulator at 
the applicable time specified in paragraph (f)(1) or (f)(2) of this 
AD in accordance with the instructions of Saab Service Bulletin 340-
29-023 or 340-29-024, both Revision 01, both dated April 3, 2009, as 
applicable.
    (1) For airplanes on which the manufacturing date of the 
hydraulic accumulator is June 2000 or earlier: Replace the 
accumulator with a new or modified accumulator within 12 months 
after the effective date of this AD.
    (2) For airplanes on which the manufacturing date of the 
accumulator is July 2000 or later: Replace the accumulator with a 
new or modified accumulator within 10 years after the manufacturing 
date or within 12 months after the effective date of this AD, 
whichever occurs later.
    (3) As of 12 months after the effective date of this AD, no 
person may install a hydraulic accumulator, P/N 08 8423 001 1 or P/N 
08 8423 030 1 on any airplane, except accumulators with serial 
numbers listed in paragraph 3.B. of Saab Service Bulletin 340-29-
023, Revision 01, dated April 3, 2009.
    (4) Actions done before the effective date of this AD in 
accordance with Saab Service Bulletin 340-29-023, dated June 10, 
2008, are acceptable for compliance with the corresponding 
requirements of this AD.

FAA AD Differences

    Note 1: This AD differs from the MCAI and/or service information 
as follows: Where the MCAI includes a compliance time of ``24 
months,'' we have determined that a compliance time of ``within 12 
months after the effective date of the AD'' is appropriate. The 
manufacturer and EASA agree with this reduction in compliance time.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
International Branch, ANM-116, 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: Shahram Daneshmandi, Aerospace 
Engineer, International Branch, ANM-116, Transport Airplane 
Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 227-1112; fax (425) 227-1149. Before using any 
approved AMOC on any airplane to which the AMOC applies, notify your 
principal maintenance inspector (PMI) or principal avionics 
inspector (PAI), as appropriate, or lacking a principal inspector, 
your local Flight Standards District Office.
    (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 European Aviation Safety Agency Airworthiness 
Directive 2008-0146R1, dated April 16, 2009, and Saab Service 
Bulletins 340-29-023 and 340-29-024, both Revision 01, both dated 
April 3, 2009, for related information.

    Issued in Renton, Washington, on August 3, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-19261 Filed 8-11-09; 8:45 am]

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