[Federal Register Volume 69, Number 207 (Wednesday, October 27, 2004)]
[Proposed Rules]
[Pages 62625-62627]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-24034]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19447; Directorate Identifier 2004-NM-97-AD]
RIN 2120-AA64


Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B 
Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Saab Model SAAB SF340A and SAAB 340B series airplanes. This 
proposed AD would require a one-time inspection to determine the part 
and serial numbers of certain molded assembly engine mounts (isolators) 
and the cure dates of certain bonded canister assemblies incorporated 
in those engine mounts; and related corrective actions if necessary. 
This proposed AD is prompted by a report that disbonding of the 
elastomer from the inner metal core and shim of certain molded assembly 
engine mounts has occurred within a few hundred hours of operation, 
causing heavy chafing of the engine support system and chafing of the 
fire sensor loop. We are proposing this AD to prevent reduced integrity 
of the fire-shielding capacity of the nacelle structure and a possible 
fire detector fault.

DATES: We must receive comments on this proposed AD by November 26, 
2004.

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.
     By 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.
    For service information identified in this proposed AD, contact 
Saab Aircraft AB, SAAB Aircraft Product Support, S-581.88, 
Link[ouml]ping, Sweden.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street SW., Room PL-401, on 
the plaza level of the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT: 
    Technical information: 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.
    Plain language information: Marcia Walters, [email protected].

SUPPLEMENTARY INFORMATION: 

Docket Management System (DMS)

    The FAA has implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, new AD actions are posted on DMS 
and assigned a docket number. We track each action and assign a 
corresponding directorate identifier. The DMS AD docket number is in 
the form ``Docket No. FAA-2004-99999.'' The Transport Airplane 
Directorate identifier is in the form ``Directorate Identifier 2004-NM-
999-AD.'' Each DMS AD docket also lists the directorate identifier 
(``Old Docket Number'') as a cross-reference for searching purposes.

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 under ADDRESSES. Include ``Docket No. FAA-2004-19447; 
Directorate Identifier 2004-NM-97-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 submitted 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://
http://dms.dot.gov">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 our 
docket 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 can review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You can get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the Docket

    You can examine the AD docket on the Internet at http://
http://dms.dot.gov">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 DMS receives them.

Discussion

    The Luftfartsverket (LFV), which is the airworthiness authority for 
Sweden,

[[Page 62626]]

notified us that an unsafe condition may exist on all Saab Model SAAB 
SF340A and SAAB 340B series airplanes. The LFV advises that disbonding 
of the elastomer from the inner metal core and shim of the bonded 
canister assemblies incorporated in certain molded assembly engine 
mounts (isolators) has occurred within a few hundred hours of 
operation. This disbonding could reduce the redundancy and change the 
stiffness and damping characteristics of the engine support system, 
cause heavy chafing of the nacelle structure, and cause chafing of the 
fire sensor loop. This condition, if not corrected, could result in 
reduced integrity of the fire-shielding capacity of the nacelle 
structure and a possible fire detector fault.

Relevant Service Information

    Saab has issued Saab Service Bulletin 340-71-059, dated May 16, 
2003. The service bulletin describes procedures for a one-time 
inspection to determine the part and serial numbers of certain molded 
assembly engine mounts (isolators) and the cure dates of certain bonded 
canister assemblies incorporated in those engine mounts; an inspection 
for chafing of the nacelle structure of all airplanes and for chafing 
of the fire sensor loop of certain airplanes; and related corrective 
actions if necessary. Corrective actions include replacement of the 
engine mounts and repair or replacement of chafed nacelle structure and 
fire sensor loop components. Accomplishing the actions specified in the 
service information is intended to adequately address the unsafe 
condition. The LFV mandated the service information and issued Swedish 
airworthiness directive SAD 1-192, dated May 16, 2003, to ensure the 
continued airworthiness of these airplanes in Sweden.
    Service Bulletin 340-71-059 refers to Barry Controls Service Letter 
93948-71-05, dated April 30, 2003, as an additional source of service 
information for determining the part numbers and serial numbers of 
certain molded assembly engine mounts, and the cure dates of the bonded 
canister assemblies incorporated in those engine mounts.

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 LFV has kept the FAA informed of 
the situation described above. We have examined the LFV's findings, 
evaluated all pertinent information, and determined that we need to 
issue an AD for products of this type design that are certificated for 
operation in the United States.
    Therefore, we are proposing this AD, which would require a one-time 
inspection to determine the part and serial numbers of certain molded 
assembly engine mounts (isolators) and the cure dates of the bonded 
canister assemblies incorporated in those engine mounts; a general 
visual inspection for chafing of certain elements adjacent to those 
engine mounts; and related corrective actions if necessary. The 
proposed AD would require you to use Saab Service Bulletin 340-71-059 
described previously to perform these actions, except as discussed 
under ``Clarification of Inspection Terminology.''

Clarification of Inspection Terminology

    Saab Service Bulletin 340-71-059 specifies an inspection for 
chafing of certain elements adjacent to certain molded assembly engine 
mounts. To eliminate any confusion about this inspection, this proposed 
AD would require a general visual inspection of those elements. Note 2 
of this proposed AD includes a definition of this type of inspection.

Costs of Compliance

    This proposed AD would affect about 170 airplanes of U.S. registry. 
The proposed actions would take about 2 work hours per airplane, at an 
average labor rate of $65 per work hour. Based on these figures, the 
estimated cost of this proposed AD for U.S. operators is $22,100 or 
$130 per airplane.

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

SAAB Aircraft AB: Docket No. FAA-2004-19447; Directorate Identifier 
2004-NM-97-AD.

Comments Due Date

    (a) The Federal Aviation Administration must receive comments on 
this AD action by November 26, 2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Model SAAB SF340A and SAAB 340B 
series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD was prompted by a report that disbonding of the 
elastomer from the inner metal core and shim of certain molded 
assembly engine mounts (isolators) has occurred within a few hundred 
hours of operation, causing heavy chafing of the engine support 
system and chafing of the fire sensor loop. We are issuing this AD 
to prevent reduced integrity of the fire-shielding capacity of the 
engine nacelle structure and a possible fire detector fault.

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

    (f) Within 500 flight hours after the effective date of this AD, 
perform a one-time inspection to determine the part and serial 
numbers of certain molded assembly engine mounts (isolators) and the 
cure dates of certain bonded canister assemblies incorporated in 
those engine mounts; and a general visual inspection for chafing of 
the

[[Page 62627]]

nacelle structure and fire sensor loop; and related corrective 
actions, as applicable; in accordance with the Accomplishment 
Instructions of Saab Service Bulletin 340-71-059, dated May 16, 
2003. Corrective actions must be accomplished prior to further 
flight.

    Note 1: Saab Service Bulletin 340-71-059 refers to Barry 
Controls Service Letter 93948-71-05, dated April 30, 2003, as an 
additional source of service information.


    Note 2: For the purposes of this AD, a general visual inspection 
is ``a visual examination of a 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 normal 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.''

Alternative Methods of Compliance (AMOCs)

    (g) 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.

Related Information

    (h) Swedish airworthiness directive SAD 1-192, dated May 16, 
2003, also addresses the subject of this AD.

    Issued in Renton, Washington, on October 18, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-24034 Filed 10-26-04; 8:45 am]
BILLING CODE 4910-13-P