[Federal Register Volume 63, Number 62 (Wednesday, April 1, 1998)]
[Proposed Rules]
[Pages 15798-15800]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8537]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-32-AD]
RIN 2120-AA64


Airworthiness Directives; Short Brothers Model SD3-60 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 all Short Brothers Model SD3-60 
series airplanes. This proposal would require a one-time inspection to 
detect discrepancies of certain diode mounting assemblies on specified 
electrical panels; follow-on actions; and repair or replacement with 
serviceable components, 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 overheating and possible failure of certain 
electrical diodes, which could result in loss of electrical service to 
one or more airplane electrical circuits.

DATES: Comments must be received by May 1, 1998.


[[Page 15799]]


ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-32-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 Short Brothers, Airworthiness & Engineering Quality, P.O. 
Box 241, Airport Road, Belfast BT3 9DZ, Northern Ireland. 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 98-NM-32-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. 98-NM-32-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, has notified the FAA that an unsafe 
condition may exist on all Short Brothers Model SD3-60 series 
airplanes. The CAA advises that overheated diodes have been found on 
electrical panel 27C. The cause of this overheating has been attributed 
to looseness of the diodes, which could cause poor electrical contact. 
These conditions, if not corrected, could result in failure of certain 
electrical diodes, which could result in loss of electrical service to 
one or more airplane electrical circuits.

Explanation of Relevant Service Information

    The manufacturer has issued Service Bulletin SD360-39-04, Revision 
1, dated January 12, 1998, which describes procedures for a one-time 
visual inspection to detect discrepancies of the diodes on electrical 
panels 1C, 2C, 12P, 27C, and 51C; follow-on actions; and repair or 
replacement with serviceable components, if necessary. The 
discrepancies include loose or overheated diodes, missing lock washers, 
overheated diode studs, and overheated electrical cables. The follow-on 
actions involve installing new lock washers, if necessary; and re-
torquing the diodes. Accomplishment of the actions specified in the 
service bulletin is intended to adequately address the identified 
unsafe condition. The CAA classified this service bulletin as mandatory 
and issued British airworthiness directive 008-09-97 (undated) in order 
to assure the continued airworthiness of these airplanes in the United 
Kingdom.

FAA's Conclusions

    This airplane model is manufactured in the United Kingdom and is 
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 CAA has kept the FAA 
informed of the situation described above. The FAA has examined the 
findings of the CAA, 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 discussed below.

Differences Between Service Bulletin and This Proposed AD

    Operators should note that, although the service bulletin specifies 
that the manufacturer should be contacted if certain damage is found, 
this proposal would require repair or replacement of discrepant parts 
with serviceable parts in accordance with a method approved by the FAA.

Cost Impact

    The FAA estimates that 88 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 14 work 
hours per airplane to accomplish the proposed actions, 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 
$73,920, or $840 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

[[Page 15800]]

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:

Short Brothers, PLC: Docket 98-NM-32-AD.

    Applicability: All Model SD3-60 series airplanes, 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 (b) 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 overheating and possible failure of certain 
electrical diodes, which could result in loss of electrical service 
to one or more airplane electrical circuits, accomplish the 
following:
    (a) Within 90 days after the effective date of this AD, perform 
a one-time visual inspection to detect discrepancies of certain 
diode mounting assemblies on electrical panels 1C, 2C, 12P, 27C, and 
51C, in accordance with Shorts Service Bulletin SD360-39-04, 
Revision 1, dated January 12, 1998.
    (1) If no discrepancy is found, prior to further flight, perform 
the follow-on actions specified in the service bulletin in 
accordance with the Accomplishment Instructions of the service 
bulletin.
    (2) If any discrepancy is found, prior to further flight, repair 
or replace the discrepant diode mounting assembly component with a 
serviceable component in accordance with a method approved by the 
Manager, International Branch, ANM-116, FAA, Transport Airplane 
Directorate.
    (b) 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. 
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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (c) 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 3: The subject of this AD is addressed in British 
airworthiness directive 008-09-97 (undated).

    Issued in Renton, Washington, on March 25, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8537 Filed 3-31-98; 8:45 am]
BILLING CODE 4910-13-U