[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