
[Federal Register: August 29, 2008 (Volume 73, Number 169)]
[Proposed Rules]               
[Page 50903-50905]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29au08-18]                         


[[Page 50903]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0115; Directorate Identifier 2007-NM-240-AD]
RIN 2120-AA64

 
Airworthiness Directives; Saab Model SAAB 2000 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:

    One Part Number (P/N) LM-219-92 Centre Bracket from a P/N LM-
219-SA28 Aft Engine Mounting assembly was found to be cracked while 
installed on the aircraft.
    This reduces the effectiveness of the mounting assembly and 
could eventually cause it to fail.
* * * * *
A failed mounting assembly, if not corrected, could result in loss of 
the engine. 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 23, 
2008.

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.

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-2008-0115; 
Directorate Identifier 2007-NM-240-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 5, 2008 (73 FR 6640). That earlier NPRM proposed to require 
actions intended to address the unsafe condition for the products 
listed above.
    Since that NPRM was issued, the European Aviation Safety Agency 
(EASA), which is the Technical Agent for the Member States of the 
European Community, has issued EASA Airworthiness Directive 2008-0068, 
dated April 11, 2008 (referred to after this as ``the MCAI''). The MCAI 
states:

    One Part Number (P/N) LM-219-92 Centre Bracket from a P/N LM-
219-SA28 Aft Engine Mounting assembly was found to be cracked while 
installed on the aircraft.
    This reduces the effectiveness of the mounting assembly and 
could eventually cause it to fail.
    EASA Airworthiness Directive (AD) was issued to require 
inspection and rework in order to make the centre bracket less 
sensitive to external damage that may result in a crack.
    This AD, superseding AD 2007-0204, has been issued to introduce 
an alternative repeatable inspection procedure.

A failed mounting assembly, if not corrected, could result in loss of 
the engine. The corrective actions include an inspection to determine 
if there are any sharp edges on the aft engine mounting assembly; 
repetitive visual inspections, or a combination of visual and 
fluorescent penetrant inspection, for cracking of the center bracket of 
the aft engine mounting assembly for both engines; rework of sharp 
edges; replacement of the aft engine mounting assemblies; and re-
identification of engine mounting assemblies and reworked center 
bracket. You may obtain further information by examining the MCAI in 
the AD docket.

Relevant Service Information

    Saab has issued Saab Service Bulletin 2000-71-025, dated June 13, 
2007, and Saab Service Bulletin 2000-71-023, Revision 01, dated June 
13, 2007. 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.

Requests To Change Unsafe Condition

    Rolls-Royce Corporation and Saab Aerosystems point out that the 
unsafe condition is stated incorrectly in the earlier NPRM. The unsafe 
condition in the earlier NPRM says ``a failed mounting assembly, if not 
corrected, could result in loss of the engine.'' The commenters state 
that the engine mounting assembly is designed as a redundant, multiple 
point mounting system and, in case of loss of one mount, the loads are 
transferred through the remaining mounts. Therefore, the mounting 
system is capable of flight with one mounting assembly completely 
inoperative, though the failure increases the load applied to the other 
mounting assemblies. Rolls-Royce states that Saab issued Service 
Bulletin 2000-71-025 (which we cited in the earlier NPRM) to ensure 
that the system redundancies are maintained.
    We disagree with the request to change the wording of the unsafe 
condition. In an unsafe condition we define the end-level effect that 
condition could have on. In this case, a failed mounting assembly could 
compromise safety as the first in a

[[Page 50904]]

potential chain of events that could result in loss of the engine. The 
unsafe condition emphasizes only the potential result by saying a 
failed mounting assembly could result in loss of the engine rather than 
saying it will result in loss of the engine. We have not changed the 
supplemental NPRM in this regard.

Request To Revise Difference Regarding Continued Flight With Cracks

    Rolls-Royce and Saab also state that the ``Differences'' section in 
the NPRM incorrectly implies that Saab Service Bulletin 2000-71-025, 
and European Aviation Safety Agency (EASA) Airworthiness Directive 
2007-0204, dated August 8, 2007, allow continued flight if a cracked 
center bracket is found. The commenters state that if any crack is 
found, the mounting assembly should be replaced before further flight.
    When we evaluated the original EASA airworthiness directive, we 
found that it states that corrective actions are to be applied within 
4,000 flight hours after its effective date. Because the EASA 
airworthiness directive does not specify that corrective actions are to 
be completed before further flight after the visual inspection, this 
means that operators can wait 4,000 flight hours to do the replacement, 
even though the inspection was required within 1,000 flight hours after 
the effective date. The service bulletin states that ``If any cracks 
are found, replace the Aft Engine Mounting Assembly,'' but does not 
give a specific time for doing that replacement. Therefore, we 
concluded that both documents can be interpreted to allow further 
flight with cracks. We also note that EASA Airworthiness Directive 
2008-0068 maintains this same wording. Therefore, we have not changed 
the supplemental NPRM in this regard.

Statement of New Service Information

    Saab states that it is working jointly with Rolls-Royce to develop 
an alternative means of compliance to the current non-destructive test 
(NDT) inspection specified in Saab Service Bulletin 2000-71-025. The 
proposed revision has been submitted to EASA and will most probably 
result in EASA issuing a revised airworthiness directive.
    As stated earlier, EASA has issued Airworthiness Directive 2008-
0068, and we have revised this supplemental NPRM accordingly. However, 
this supplemental NPRM still refers to Saab Service Bulletin 2000-71-
025 because the service bulletin has not been revised. This 
supplemental NPRM also now refers to Saab Service Bulletin 2000-71-023, 
Revision 01 as an acceptable source of service information for doing 
certain actions. Once new service information is developed, approved, 
and available, we might consider additional rulemaking. We have not 
changed the AD in this regard.

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 about 6 products of U.S. registry. We also estimate that 
it would take about 8 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $80 per 
work-hour. Based on these figures, we estimate the cost of the proposed 
AD on U.S. operators to be $3,840, or $640 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:


[[Page 50905]]


Saab Aircraft AB: Docket No. FAA-2008-0115; Directorate Identifier 
2007-NM-240-AD.

Comments Due Date

    (a) We must receive comments by September 23, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Saab Model SAAB 2000 airplanes, 
certificated in any category, serial number 004 through 063.

Subject

    (d) Air Transport Association (ATA) of America Code 71: 
Powerplant.

Reason

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

    One Part Number (P/N) LM-219-92 Centre Bracket from a P/N LM-
219-SA28 Aft Engine Mounting assembly was found to be cracked while 
installed on the aircraft.
    This reduces the effectiveness of the mounting assembly and 
could eventually cause it to fail.
    EASA Airworthiness Directive (AD) was issued to require 
inspection and rework in order to make the centre bracket less 
sensitive to external damage that may result in a crack.
    This AD, superseding AD 2007-0204, has been issued to introduce 
an alternative repeatable inspection procedure.

A failed mounting assembly, if not corrected, could result in loss 
of the engine. The corrective actions include an inspection to 
determine if there are any sharp edges on the aft engine mounting 
assembly; repetitive visual inspections, or a combination of visual 
and fluorescent penetrant inspection, for cracking of the center 
bracket of the aft engine mounting assembly for both engines; rework 
of sharp edges; replacement of the aft engine mounting assemblies; 
and re-identification of engine mounting assemblies and reworked 
center bracket.

Actions and Compliance

    (f) Unless already done, do the following actions.
    (1) Within 1,000 flight hours after the effective date of this 
AD, do visual inspections of both the aft engine mounting assemblies 
to find if the center bracket is correct (no sharp edges) from the 
manufacturer.
    (2) If no sharp edge is found during the inspection required by 
paragraph (f)(1) of this AD, before further flight, inspect to 
determine if the aft engine mounting assembly and center bracket are 
identified with a ``-1'' and before further flight re-identify the 
parts that are not identified with a ``-1'' in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 2000-71-025, 
dated June 13, 2007. Following the re-identification, no further 
action is required by this AD for airplanes on which no sharp edge 
is found during the inspection required by paragraph (f)(1) of this 
AD.
    (3) If any sharp edge is found during the inspection required by 
paragraph (f)(1) of this AD, before further flight, do the action in 
paragraph (f)(3)(i) or (f)(3)(ii) of this AD in accordance with the 
Accomplishment Instructions of Saab Service Bulletin 2000-71-025, 
dated June 13, 2007.
    (i) Do a general visual inspection for cracking of the center 
bracket of both of the aft engine mounting assemblies, with the 
bracket on the wing, and repeat the inspection thereafter at 
intervals not to exceed 250 flight hours until the action required 
by paragraph (f)(4) of this AD is accomplished.
    (ii) Do general visual and penetrant inspections for cracking of 
the center bracket of both of the aft engine mounting assemblies, 
with the bracket off the wing.

    Note 1: For the purposes of this AD, a general visual inspection 
is: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of inspection is made from within touching 
distance unless otherwise specified. A mirror may be necessary to 
ensure visual access to all surfaces in the inspection area. This 
level of inspection is made under normally available lighting 
conditions such as daylight, hangar lighting, flashlight, or 
droplight and may require removal or opening of access panels or 
doors. Stands, ladders, or platforms may be required to gain 
proximity to the area being checked.''

    (4) At the applicable time in paragraph (f)(4)(i) or (f)(4)(ii) 
of this AD, do the applicable actions in those paragraphs in 
accordance with the Accomplishment Instructions of Saab Service 
Bulletin 2000-71-025, dated June 13, 2007. Doing the applicable 
action terminates the repetitive inspection requirements of 
paragraph (f)(3)(i) of this AD.
    (i) If no cracking is found during any inspection required by 
paragraph (f)(3) of this AD: Within 4,000 flight hours after the 
effective date of this AD, rework the center bracket, and re-
identify the aft engine mounting assembly and center bracket.
    (ii) If any cracking is found during any inspection required by 
paragraph (f)(3) of this AD, before further flight, replace the aft 
engine mounting assembly with an assembly and bracket identified 
with a ``-1'' part number.
    (5) Actions done before the effective date of this AD in 
accordance with Saab Service Bulletin 2000-71-023, Revision 01, 
dated June 13, 2007, are acceptable for compliance with the 
corresponding requirements of paragraph (f)(3) of this AD.

FAA AD Differences

    Note 2: This AD differs from the MCAI and/or service information 
as follows:
    (1) Although the MCAI or service information allows further 
flight after cracks are found during compliance with the required 
action, paragraph (f)(4) of this AD requires that you replace a 
cracked aft engine mounting assembly before further flight.

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, 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: 
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 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 European Aviation Safety Agency (EASA) 
Airworthiness Directive 2008-0068, dated April 11, 2008, and Saab 
Service Bulletin 2000-71-025, dated June 13, 2007, for related 
information.

    Issued in Renton, Washington, on August 20, 2008.
Kevin Hull,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-20088 Filed 8-28-08; 8:45 am]

BILLING CODE 4910-13-P
