[Federal Register Volume 59, Number 24 (Friday, February 4, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-2526]
[[Page Unknown]]
[Federal Register: February 4, 1994]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 93-NM-233-AD]
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 an inspection
of the elevator and aileron coves, and further inspections and repair,
if necessary. This proposal is prompted by a report of delamination
between the composite structure and the aluminum foil on the elevator
cove on a Model SAAB SF340B series airplane. The design of the aileron
cove is similar to that of the elevator cove on Model SAAB SF340A and
SAAB 340B series airplanes. The actions specified by the proposed AD
are intended to prevent jamming of the aileron or elevator.
DATES: Comments must be received by April 4, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 93-NM-233-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9 a.m. and 3 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: Mark Quam, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2145; fax (206) 227-1320.
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 93-NM-233-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-103, Attention: Rules
Docket No. 93-NM-233-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Luftfartsverket (LFV), which is the airworthiness authority for
Sweden, recently notified the FAA that an unsafe condition may exist on
certain Saab Aircraft AB Model SAAB SF340A and SAAB 340B series
airplanes. The LFV advises that, when the pilot of a Model SAAB SF340B
series airplane disengaged the autopilot during approach for landing,
the elevators required additional force in order to be operated
correctly. Investigation revealed that delamination had occurred
between the composite structure and the aluminum foil on the elevator
cove. When water entered the delaminated area and froze, the aluminum
foil was raised further, causing contact with the elevator. The design
of the aileron cove is similar to that of the elevator cove on Model
SAAB SF340A and SAAB 340B series airplanes. The design consists of a
composite structure with a conductive layer, which is composed of
aluminum foil, conductive paint, or expanded aluminum foil (stretched
metal--aluminum net). Delamination and freezing of trapped water in the
aileron or elevator could lead to jamming of these parts.
Saab has issued Service Bulletin 340-51-012, dated November 10,
1993, that describes procedures for an inspection of the elevator and
aileron coves to verify the type of antistatic protection (black
conductive paint or expanded aluminum foil (an aluminum net)) applied
to the coves. For coves that are found without conductive paint or
expanded aluminum foil, the service bulletin describes procedures for a
detailed visual inspection and delamination tap test to detect aluminum
foil delamination on the coves; and either a temporary repair and
repetitive detailed visual inspections and delamination tap tests of
the coves, or a permanent repair of the coves. The temporary repair
involves applying aluminum tape or conductive paint to the delaminated
area, and accomplishing repetitive detailed visual inspections and
delamination tap tests of the cove. The permanent repair entails either
applying conductive paint or expanded aluminum foil (stretched metal--
aluminum net) to the cove. Accomplishment of the permanent repair would
terminate the repetitive detailed visual inspections and delamination
tap tests. The LFV classified this service bulletin as mandatory and
issued Swedish Airworthiness Directive No. 1-060, dated November 15,
1993, in order to assure the continued airworthiness of these airplanes
in Sweden.
This airplane model is manufactured in Sweden and is type
certificated for operation in the United States under the provisions of
Sec. 21.29 of the Federal Aviation Regulations 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.
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 an inspection of
the elevator and aileron coves to verify the type of antistatic
protection applied to the coves. For coves that are found without
conductive paint or expanded aluminum foil, the proposed AD would
require a detailed visual inspection and delamination tap test to
detect aluminum foil delamination on the coves; and either a temporary
repair and repetitive detailed visual inspections and delamination tap
tests of the coves, or a permanent repair of the coves. Accomplishment
of the permanent repair would terminate the repetitive detailed visual
inspections and delamination tap tests. The actions would be required
to be accomplished in accordance with the service bulletin described
previously.
The FAA estimates that 152 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 20 work
hours per airplane to accomplish the proposed inspection, and that the
average labor rate is $55 per work hour. Based on these figures, the
total cost impact of the proposed AD on U.S. operators is estimated to
be $167,200, or $1,100 per airplane. This total cost figure assumes
that no operator has yet accomplished the proposed requirements of this
AD action.
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 14
CFR part 39 of the Federal Aviation Regulations as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
SAAB Aircraft AB: Docket 93-NM-233-AD.
Applicability: Model SAAB SF340A series airplanes, serial
numbers -004 through -159 inclusive; and Model SAAB 340B series
airplanes, serial numbers -160 through -260 inclusive; certificated
in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent jamming of the aileron or elevator, accomplish the
following:
(a) Within 500 hours time-in-service or 90 days after the
effective date of this AD, whichever occurs first, perform an
inspection of the elevator and aileron coves to verify the type of
antistatic protection applied to the coves, in accordance with SAAB
Service Bulletin 340-51-012, dated November 10, 1993.
(b) If a cove has conductive paint or expanded aluminum foil
(stretched metal--aluminum net), no further action is required by
this AD for that cove.
(c) If a cove does not have conductive paint or expanded
aluminum foil (stretched metal--aluminum net), prior to further
flight, perform a detailed visual inspection and delamination tap
test to detect aluminum foil delamination on the elevator or aileron
cove, in accordance with the service bulletin.
(1) If no delamination is found, repeat the detailed visual
inspection and delamination tap test thereafter at intervals not to
exceed 800 hours time-in-service in accordance with the service
bulletin.
(2) If any delamination is found, prior to further flight,
accomplish either paragraph (c)(2)(i) or (c)(2(ii) of this AD.
(i) Perform a temporary repair of the cove in accordance with
the service bulletin. Thereafter, repeat the detailed visual
inspection and delamination tap test required by paragraph (c) of
this AD at intervals not to exceed 800 hours time-in-service. Or
(ii) Perform a permanent repair of the cove in accordance with
the service bulletin. Accomplishment of this permanent repair
constitutes terminating action for the repetitive inspection
required by this AD.
(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, Standardization Branch, ANM-113,
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,
Standardization Branch, ANM-113.
Note: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(e) Special flight permits may be issued in accordance with
Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the
airplane to a location where the requirements of this AD can be
accomplished.
Issued in Renton, Washington, on January 31, 1994.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-2526 Filed 2-3-94; 8:45 am]
BILLING CODE 4910-13-U
