[Federal Register Volume 64, Number 149 (Wednesday, August 4, 1999)]
[Proposed Rules]
[Pages 42291-42293]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-20066]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-52-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 repetitive inspections of 
the elevator trim control cables for signs of wear damage or broken 
wires; replacement of damaged or broken cables with certain new cables; 
and replacement of all 7x7 cables with 7 x 19 cables. 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 failure of the elevator trim 
cable due to fatigue cracking, which if not corrected, could result in 
reduced controllability of the airplane.

DATES: Comments must be received by September 3, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-52-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-52-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

[[Page 42292]]

FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket 
No. 99-NM-52-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 SD3-60 series 
airplanes. The CAA advises that three incidents have occurred in which 
segments of the elevator trim cabling system have failed. In each case, 
the cable fractured during flight, and on two of the airplanes, the 
cable segments that control the nose-up trim failed at identical 
locations adjacent to pulleys. Metallurgical examinations established 
that all three separations were the result of fatigue cracking of the 
individual wire strands in the cable. This condition, if not corrected, 
could result in reduced controllability of the airplane.

Explanation of Relevant Service Information

    Bombardier has issued Shorts Service Bulletin SD360-27-27, Revision 
1, dated April 1, 1999, which describes procedures for repetitive 
inspections of the elevator trim control cables for signs of wear 
damage or broken wires. The service bulletin also describes procedures 
for replacement of any cable with worn, broken or frayed wires; and 
replacement of all 7 x 7 cables with 7 x 19 cables. 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 016-11-98 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 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 service bulletin described previously.

Cost Impact

    The FAA estimates that 45 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 cable inspection, and 
that the average labor rate is $60 per work hour. Based on these 
figures, the cost impact of the cable inspection proposed by this AD on 
U.S. operators is estimated to be $54,000, or $1,200 per airplane, per 
inspection cycle.
    The FAA estimates that it would take approximately 75 work hours 
per airplane to accomplish the proposed cable replacement, and that the 
average labor is $60 per work hour. Required parts would cost 
approximately $4,500 per airplane. Based on these figures, the cost 
impact of the cable replacement proposed by this AD on U.S. operators 
is estimated to be $405,000, or $9,000 per airplane.
    The cost impact figures discussed above are 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-52-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 (c) 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 failure of the elevator trim cable due to fatigue, 
which if not corrected, could result in reduced controllability of 
the airplane, accomplish the following:

Inspection

    (a) Within 12 months after the effective date of this AD, 
perform a visual inspection to detect wear damage or broken wires of 
the elevator trim cables, in accordance with Shorts Service Bulletin 
SD3-60-27-27, Revision 1, dated April 1, 1999.
    (1) If no wear damage or broken wire is detected, repeat the 
inspection specified in paragraph (a) of this AD thereafter at 
intervals not to exceed 12 months or 2,400 flight hours, whichever 
occurs first.
    (2) If any wear damage or broken wire is detected, prior to 
further flight, replace the damaged cable with a 7 x 19 cable in 
accordance with the service bulletin. Repeat

[[Page 42293]]

the inspection specified in paragraph (a) of this AD thereafter at 
intervals not to exceed 12 months or 2,400 flight hours, whichever 
occurs first.

Replacement and Inspection

    (b) Prior to the accumulation of 10,000 total flight hours, or 
within 12 months after the effective date of this AD, whichever 
occurs later, replace all 7 x 7 elevator trim cables with 7 x 19 
cables in accordance with Shorts Service Bulletin SD3-60-27-27, 
Revision 1, dated April 1, 1999. Repeat the inspection specified in 
paragraph (a) of this AD thereafter at intervals not to exceed 12 
months or 2,400 flight hours, whichever occurs first.

Alternative Methods of Compliance

    (c) 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

    (d) Special flight permits may be issued in accordance with 
Secs. 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 the British 
airworthiness directive 016-11-98.

    Issued in Renton, Washington, on July 28, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-20066 Filed 8-3-99; 8:45 am]
BILLING CODE 4910-13-U