[Federal Register Volume 65, Number 3 (Wednesday, January 5, 2000)]
[Proposed Rules]
[Pages 395-396]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-138]
[[Page 395]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-51-AD]
RIN 2120-AA64
Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Saab Model SAAB SF340A and
SAAB 340B series airplanes. This proposal would require a one-time
inspection to detect corrosion and scratches on the bearing housing
surfaces of the support assembly on the main landing gear (MLG), and
corrective actions, if necessary. This proposal is prompted by issuance
of mandatory continuing airworthiness information by a foreign civil
airworthiness authority. The actions specified by the proposed AD are
intended to prevent corrosion in the inboard and outboard bearing
housings of the MLG support assembly, which could result in fatigue
cracks in the support assembly and lead to failure of the MLG.
DATES: Comments must be received by February 4, 2000.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-51-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056. Comments may be inspected at this location
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal
holidays.
The service information referenced in the proposed rule may be
obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Linkoping, Sweden. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2110; fax (425) 227-1149.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 99-NM-51-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules
Docket No. 99-NM-51-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Luftfartsverket (LFV), which is the airworthiness authority for
Sweden, notified the FAA that an unsafe condition may exist on certain
Saab Model SAAB SF340A and SAAB 340B series airplanes. The LFV advises
that, during replacement of landing gear support assembly bearings,
pitting corrosion has been found in the outboard and inboard bearing
housings. The corrosion is believed to be caused by intrusion of
moisture between the bearing and its housing surface. Such corrosion,
if not corrected, could result in fatigue cracks in the support
assembly and lead to failure of the main landing gear (MLG).
Explanation of Relevant Service Information
Saab has issued Service Bulletin 340-57-036, dated October 20,
1999, which describes a one-time visual inspection to detect corrosion
and scratches on the bearing housing surfaces of the support assembly
on the MLG. The service bulletin also describes procedures for
corrosion removal, an eddy current inspection, and repair if corrosion
or scratches are found. Accomplishment of the actions specified in the
service bulletin is intended to adequately address the identified
unsafe condition. The LFV classified this service bulletin as mandatory
and issued Swedish airworthiness directive No. 1-146, dated October 20,
1999, in order to ensure the continued airworthiness of these airplanes
in Sweden.
FAA's Conclusions
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. The FAA has examined the findings of the
LFV, reviewed all available information, and determined that AD action
is necessary for products of this type design that are certificated for
operation in the United States.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, the proposed AD would require accomplishment of
the actions specified in the service bulletin described previously,
except as described below.
Differences Between Proposed AD and Service Bulletin
Operators should note that, although the service bulletin specifies
that the manufacturer may be contacted for disposition of certain
conditions, this proposal would require the repair of those conditions
to be accomplished in accordance with a method approved by the FAA or
the LFV.
[[Page 396]]
Cost Impact
The FAA estimates that 291 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 2 work
hours per airplane to accomplish the proposed inspection, and that the
average labor rate is $60 per work hour. Based on these figures, the
cost impact of the proposed AD on U.S. operators is estimated to be
$34,920, or $120 per airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the proposed requirements of
this AD action, and that no operator would accomplish those actions in
the future if this AD were not adopted.
Regulatory Impact
The regulations proposed herein would not have substantial direct
effects 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. Therefore, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that 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) if promulgated, 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. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new
airworthiness directive:
SAAB Aircraft AB: Docket 99-NM-51-AD.
Applicability: Model SAAB SF340A, serial numbers 004 through 159
inclusive; and SAAB 340B series airplanes, serial numbers 160
through 444 inclusive; certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (d) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To prevent corrosion in the inboard and outboard bearing
housings of the support assembly of the main landing gear (MLG),
which could result in fatigue cracks in the support assembly and
lead to failure of the MLG, accomplish the following:
(a) At the applicable time specified in paragraph (a)(1),
(a)(2), (a)(3), or (a)(4) of this AD: Perform a one-time general
visual inspection of the eight bearing housing surfaces of the MLG
to detect corrosion or scratches, in accordance with Saab Service
Bulletin 340-57-036, dated October 20, 1999.
(1) For airplanes with 32,000 or more total flight cycles as of
the effective date of this AD, the inspection is to be performed
within 4,000 flight cycles after the effective date of this AD.
(2) For airplanes with 24,000 or more and fewer than 32,000
total flight cycles as of the effective date of this AD, the
inspection is to be performed within 6,000 flight cycles after the
effective date of this AD.
(3) For airplanes with 12,000 or more and fewer than 24,000
total flight cycles as of the effective date of this AD, the
inspection is to be performed prior to the accumulation of 24,000
total flight cycles, or within 6,000 flight cycles after the
effective date of this AD, whichever occurs later.
(4) For airplanes with fewer than 12,000 total flight cycles as
of the effective date of this AD, the inspection is to be performed
prior to the accumulation of 12,000 total flight cycles, or within
6,000 flight cycles after the effective date of this AD, whichever
occurs later.
Note 2: For the purposes of this AD, a general visual inspection
is defined as: ``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 under normally
available lighting conditions such as daylight, hangar lighting,
flashlight, or drop-light, 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.''
(b) Except as provided by paragraph (c) of this AD: If, during
the inspection required by paragraph (a) of this AD, any corrosion
or scratch is detected that is within the limits specified in Saab
Service Bulletin 340-57-036, dated October 20, 1999, prior to
further flight, perform corrective actions (including rework, an
eddy current inspection, and repair) in accordance with steps 2.B.
and 2.C. of the Accomplishment Instructions of the service bulletin.
(c) If, during any inspection required by this AD, a discrepancy
is detected for which the service bulletin specifies to contact Saab
for appropriate action [including any crack or any corrosion or
scratch that exceeds 1.1 mm (0.043 in) after applicable rework has
been performed as required by paragraph (b) of this AD]: Prior to
further flight, repair in accordance with a method approved by the
Manager, International Branch, ANM-116, Transport Airplane
Directorate; or the Luftfartsverket (LFV) (or its delegated agent).
For a repair method to be approved by the Manager, International
Branch, ANM-116, as required by this paragraph, the Manager's
approval letter must specifically reference this AD.
Alternative Methods of Compliance
(d) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, International Branch, ANM-116, FAA,
Transport Airplane Directorate. Operators shall submit their
requests through an appropriate FAA Principal Maintenance Inspector,
who may add comments and then send it to the Manager, International
Branch, ANM-116.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
Special Flight Permits
(e) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Note 4: The subject of this AD is addressed in Swedish
airworthiness directive No. 1-146, dated October 20, 1999.
Issued in Renton, Washington, on December 29, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 00-138 Filed 1-4-00; 8:45 am]
BILLING CODE 4910-13-U
