[Federal Register Volume 64, Number 190 (Friday, October 1, 1999)]
[Rules and Regulations]
[Pages 53191-53192]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25596]



[[Page 53191]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-29-AD; Amendment 39-11345; AD 99-21-02]
RIN 2120-AA64


Airworthiness Directives; Short Brothers Model SD3-30, SD3-60, 
SD3-SHERPA, and SD3-60 SHERPA Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all Short Brothers Model SD3-30, SD3-60, SD3-SHERPA, and 
SD3-60 SHERPA series airplanes, that requires detailed visual and 
borescopic inspections to detect corrosion of the engine mounting tube 
assembly, and replacement of corroded parts with new or serviceable 
parts. This amendment is prompted by issuance of mandatory continuing 
airworthiness information by a foreign civil airworthiness authority. 
The actions specified by this AD are intended to prevent failure of the 
engine mounting tube assembly, which could result in loss of the engine 
in flight.

DATES: Effective November 5, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 5, 1999.

ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration 
(FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, 
SW., Renton, Washington; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all Short Brothers Model SD3-30, 
SD3-60, SD3-SHERPA, and SD3-60 SHERPA series airplanes was published in 
the Federal Register on June 28, 1999 (64 FR 34582). That action 
proposed to require detailed visual and borescopic inspections to 
detect corrosion of the engine mounting tube assembly, and replacement 
of corroded parts with new or serviceable parts.

Comments Received

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Extend Compliance Time

    The manufacturer requests that the FAA extend the proposed 
compliance time from 6 months to 9 months. The manufacturer supports 
its request based on the results of an airframe structural analysis, 
ongoing inspections, and the Civil Aviation Authority of the United 
Kingdom's acceptance of the 3-month extension. The FAA has reviewed the 
data presented by the manufacturer and concurs with the request. The 
final rule has been revised accordingly.

Explanation of Additional Change to Proposal

    The FAA has added a note to the final rule to clarify the 
definition of a detailed visual inspection.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 137 Model SD3-30, SD3-60, SD3-SHERPA, and 
SD3-60 SHERPA series airplanes of U.S. registry will be affected by 
this AD, that it will take approximately 25 work hours per airplane to 
accomplish the required actions, and that the average labor rate is $60 
per work hour. Based on these figures, the cost impact of the AD on 
U.S. operators is estimated to be $205,500, or $1,500 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the 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 adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

99-21-02  Short Brothers PLC: Amendment 39-11345. Docket 99-NM-29-
AD.

    Applicability: All Model SD3-30, SD3-60, SD3-SHERPA, and SD3-60 
SHERPA 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

[[Page 53192]]

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 engine mounting tube assembly, which 
could result in loss of the engine in flight, accomplish the 
following:

Inspections

    (a) Within 9 months after the effective date of this AD, perform 
a detailed visual inspection of the taper pins of the engine 
mounting tube assembly for corrosion in accordance with Shorts 
Service Bulletins SD330-71-23, dated November 20, 1998, or Revision 
1, dated April 26, 1999 (for Model SD3-30 series airplanes); SD3 
SHERPA-71-1, Revision 1, dated February 3, 1999, or Revision 2, 
dated April 26, 1999 (for Model SD3-SHERPA series airplanes); SD3-60 
SHERPA-71-1, Revision 1, dated February 3, 1999, or Revision 2, 
dated April 26, 1999 (for Model SD3-60 SHERPA series airplanes); or 
SD360-71-18, Revision 1, dated February 3, 1999, or Revision 2, 
dated April 26, 1999 (for Model SD3-60 series airplanes); as 
applicable. If corrosion is found on any taper pin, prior to further 
flight, replace the pin with a new or serviceable pin.

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as: ``As an intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or irregularity. Available lighting is 
normally supplemented with a direct source of good light at 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''

    (b) Within 9 months after the effective date of this AD, perform 
a borescopic inspection of the internal surface of the engine 
mounting tubes and fittings for corrosion, in accordance with Shorts 
Service Bulletins SD330-71-23, dated November 20, 1998, or Revision 
1, dated April 26, 1999 (for Model SD3-30 series airplanes); SD3 
SHERPA-71-1, Revision 1, dated February 3, 1999, or Revision 2, 
dated April 26, 1999 (for Model SD3-SHERPA series airplanes); SD3-60 
SHERPA-71-1, Revision 1, dated February 3, 1999, or Revision 2, 
dated April 26, 1999 (for Model SD3-60 SHERPA series airplanes); or 
SD360-71-18, Revision 1, dated February 3, 1999, or Revision 2, 
dated April 26, 1999 (for Model SD3-60 series airplanes); as 
applicable.
    (1) If no corrosion is found on the internal surface of the 
engine mounting tubes and fittings, no further action is required by 
this paragraph.
    (2) If corrosion is found that is within the limits as defined 
in the applicable service bulletin, repeat the borescopic inspection 
thereafter at intervals not to exceed 9 months. Replacement of all 
corroded parts with new or serviceable parts in accordance with the 
applicable service bulletin constitutes terminating action for the 
repetitive borescopic inspections required by this AD.
    (3) If corrosion is found that is outside the limits as defined 
in the applicable service bulletin, prior to further flight, replace 
the corroded parts with new or serviceable parts, in accordance with 
the applicable service bulletin.

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 3: 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 
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.

Incorporation by Reference

    (e) The actions shall be done in accordance with the following 
Shorts service bulletins, as applicable, which contain the specified 
effective pages:

----------------------------------------------------------------------------------------------------------------
                                                     Revision level shown on
 Service bulletin referenced and date    Page No.             page                    Date shown on page
----------------------------------------------------------------------------------------------------------------
SD330-71-23, November 20, 1998.......         1-11  Original................  November 20, 1998.
SD330-71-23, Revision 1, April 26,            1, 2  1.......................  April 26, 1999.
 1999.                                        3-11  Original................  November 20, 1998.
SD3 SHERPA-71-1, Revision 1, February       1, 6-8  1.......................  February 3, 1999.
 3, 1999.                                2-5, 9-11  Original................  November 20, 1998.
SD3 SHERPA-71-1, Revision 2, April            1, 2  2.......................  April 26, 1999.
 26, 1999.                               3-5, 9-11  Original................  November 20, 1998.
                                               6-8  1.......................  February 3, 1999.
SD3-60 SHERPA-71-1, Revision 1,             1, 6-8  1.......................  February 3, 1999.
 February 3, 1999.                       2-5, 9-11  Original................  November 20, 1998.
SD3-60 SHERPA-71-1, Revision 2, April         1, 2  2.......................  April 26, 1999.
 26, 1999.                               3-5, 9-11  Original................  November 20, 1998.
                                               6-8  1.......................  February 3, 1999.
SD360-71-18, Revision 1, February 3,       1, 6, 8  1.......................  February 3, 1999.
 1999.                                  2-5, 7, 9-  Original................  November 24, 1998.
                                                11
SD360-71-18, Revision 2, April 26,            1, 2  2.......................  April 26, 1999.
 1999.                                  3-5, 7, 9-  Original................  November 24, 1998.
                                                11    ......................
                                              6, 8  1.......................  February 3, 1999
----------------------------------------------------------------------------------------------------------------

    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from Short Brothers, Airworthiness & 
Engineering Quality, P.O. Box 241, Airport Road, Belfast BT3 9DZ, 
Northern Ireland. Copies may be inspected at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 
at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.

    Note 4: The subject of this AD is addressed in British 
airworthiness directives 014-11-98, 018-11-98, 011-11-98, and 012-
11-98.

    (f) This amendment becomes effective on November 5, 1999.

    Issued in Renton, Washington, on September 27, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-25596 Filed 9-30-99; 8:45 am]
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