[Federal Register Volume 64, Number 123 (Monday, June 28, 1999)]
[Proposed Rules]
[Pages 34581-34582]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-16333]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-12-AD]
RIN 2120-AA64


Airworthiness Directives; Short Brothers Model SD3-SHERPA, SD3-60 
SHERPA, SD3-30, and 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-
SHERPA, SD3-60 SHERPA, SD3-30, and SD3-60 series airplanes. This 
proposal would require replacement of the existing bolts that secure 
the elevator control torque tube bearing housing retaining plate with 
hex head bolts. 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 reduced movement of the elevator controls and consequent 
reduced controllability of the airplane, as a result of bolts coming 
loose on the elevator control torque tube bearing housing retaining 
plate.

DATES: Comments must be received by July 28, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-12-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 99-NM-12-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-12-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, notified the FAA that an unsafe 
condition may exist on all Short Brothers Model SD3-SHERPA, SD3-60 
SHERPA, SD3-30, and SD3-60 series airplanes. The CAA advises that the 
bolts that secure the elevator control torque tube bearing housing 
retaining plate to the pilots seat pedestal were found loose. The bolts 
became loose due to the existing design of the bolts, which does not 
allow for proper torquing upon installation. This condition, if not 
corrected, could result in bolts coming loose on the elevator control 
torque tube bearing housing retaining plate which could result in 
reduced movement of the elevator controls and consequent reduced 
controllability of the airplane.

Explanation of Relevant Service Information

    Short Brothers has issued the following service bulletins:
     SD3 Sherpa-27-3, Revision 1, dated November 23, 1998 (for 
Model SD3-SHERPA series airplanes);
     SD3-60 Sherpa-27-3, Revision 1, dated November 23, 1998 
(for Model SD3-60 SHERPA series airplanes);
     SD330-27-37, Revision 1, dated November 23, 1998 (for 
Model SD3-30 series airplanes); and
     SD360-27-28, Revision 1, dated November 23, 1998 (for 
Model SD3-60 series airplanes).

These service bulletins describe procedures for replacement of the 
existing bolts that secure the elevator control torque tube bearing 
housing retaining plate with hex head bolts. Accomplishment of the 
actions specified in the service bulletins is intended to adequately 
address the identified unsafe condition. The CAA classified these 
service bulletins as mandatory and issued British airworthiness 
directives 009-11-98, 010-11-98, 013-11-98, and 017-11-98, in order to 
assure the continued airworthiness of these airplanes in the United 
Kingdom.

FAA's Conclusions

    These airplane models are manufactured in the United Kingdom

[[Page 34582]]

and are type certificated for operation in the United States under the 
provisions of Sec. 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 applicable service bulletin described 
previously.

Cost Impact

    The FAA estimates that 46 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 4 work 
hours per airplane to accomplish the proposed replacement, and that the 
average labor rate is $60 per work hour. Required parts would come from 
the operator's existing supply. Based on these figures, the cost impact 
of the proposed AD on U.S. operators is estimated to be $11,040, or 
$240 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:

Short Brothers PLC: Docket 99-NM-12-AD.

    Applicability: All Model SD3-SHERPA, SD3-60 SHERPA, SD3-30, and 
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 reduced movement of the elevator controls and 
consequent reduced controllability of the airplane, as a result of 
bolts coming loose on the elevator control torque tube bearing 
housing retaining plate, accomplish the following:

Replacement

    (a) Within 6 months after the effective date of this AD, replace 
the existing bolts of the elevator control torque tube bearing 
housing retaining plate with hex head bolts torqued to a value of 35 
lb-ins, in accordance with Shorts Service Bulletins SD3 Sherpa-27-3, 
Revision 1, dated November 23, 1998 (for Model SD3-SHERPA series 
airplanes); SD3-60 Sherpa-27-3, Revision 1, dated November 23, 1998 
(for Model SD3-60 SHERPA series airplanes); SD330-27-37, Revision 1, 
dated November 23, 1998 (for Model SD3-30 series airplanes); or 
SD360-27-28, Revision 1, dated November 23, 1998 (for Model SD3-60 
series airplanes); as applicable.

Alternative Method of Compliance

    (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, 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 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.

Special Flight Permits

    (c) Special flight permits may be issued in accordance with 
Sec. Sec. 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 directives 009-11-98, 010-11-98, 013-11-98, and 017-
11-98.

    Issued in Renton, Washington, on June 22, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-16333 Filed 6-25-99; 8:45 am]
BILLING CODE 4910-13-U