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[Federal Register Volume 63, Number 142 (Friday, July 24, 1998)]
[Proposed Rules]
[Pages 39769-39771]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-19778]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-106-AD]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to all Short Brothers Model SD3-60 series 
airplanes, that would have required repetitive inspections to detect 
corrosion and/or wear of the top and bottom shear decks of the left and 
right stub wings in the area of the forward pintle pin of the main 
landing gear (MLG), and repair, if necessary. That proposal was 
prompted by issuance of mandatory continuing airworthiness information 
by a foreign civil airworthiness authority. This new action revises the 
proposed rule by expanding the applicability to include an additional 
airplane model. The actions specified by this new proposed AD are 
intended to detect and correct corrosion and/or wear of the top and 
bottom shear decks of the left and right stub wings in the area of the 
forward pintle pin of the MLG, which could result in failure of the MLG 
to extend or retract.

DATES: Comments must be received by August 18, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-106-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 97-NM-106-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. 97-NM-106-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to all 
Short Brothers Model SD3-60 series airplanes, was published as a notice 
of proposed rulemaking (NPRM) in the Federal Register on October 6, 
1997 (62 FR 52053). That NPRM would have required repetitive 
inspections to detect corrosion and/or wear of the top and bottom shear 
decks of the left and right stub wings in the area of the forward 
pintle pin of the main landing gear (MLG), and repair, if necessary. 
That NPRM was prompted by reports of corrosion and/or wear of the top 
and bottom shear decks of the left and right stub wings in the area of 
the forward pintle pin of the MLG. Such corrosion or wear of the top 
and bottom shear decks of the left and right stub wings in the area of 
the forward pintle pin of the MLG, if not corrected, could result in 
failure of the MLG to extend or retract.

Actions Since Issuance of Previous Proposal

    Since the issuance of that NPRM, the Civil Aviation Authority 
(CAA), which is the airworthiness authority for the United Kingdom, 
notified the FAA that the unsafe condition described in the original 
NPRM also may exist on all Short Brothers Model SD3-60 SHERPA series 
airplanes. The shear decks of the stub wings on Model SD3-60 SHERPA 
series airplanes are similar in design to those on Model SD3-60 series 
airplanes; therefore, both models are subject to the same unsafe 
condition. The FAA has revised the applicability of this

[[Page 39770]]

supplemental NPRM to add Model SD3-60 SHERPA series airplanes.

New Service Information

    Short Brothers has issued Service Bulletin SD3-60 SHERPA-53-3, 
dated November 4, 1997, which describes procedures for repetitive 
inspections to detect corrosion and/or wear of the top and bottom shear 
decks of the left and right stub wings in the area of the forward 
pintle pin of the MLG, and repair, if necessary. For airplanes on which 
certain depths of corrosion or wear is detected, the service bulletin 
describes procedures for a visual inspection to detect any discrepancy 
of the pintle pin and sleeve. The CAA classified this service bulletin 
as mandatory and issued British airworthiness directive 005-11-97 in 
order to assure the continued airworthiness of these airplanes in the 
United Kingdom.
    The FAA has revised this supplemental NPRM to reference this 
service bulletin as the appropriate source of service information for 
accomplishment of the actions proposed by this AD for Model SD3-60 
SHERPA series airplanes.

Explanation of Change Made to NPRM

    In the original NPRM, the FAA inadvertently omitted a paragraph 
requiring operators to repeat the inspection for corrosion of the top 
and bottom shear decks of the left and right stub wings at intervals 
not to exceed 6 months even if no corrosion, wear, or discrepancy of 
the measurement of the holes for the retaining pin of the pintle pin is 
found. Accordingly, the FAA has included this requirement in paragraph 
(a)(1) of this supplemental NPRM.

Conclusion

    Since these changes expand the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.

Cost Impact

    The FAA estimates that 58 Model SD3-60 series airplanes and 28 
Model SD3-60 SHERPA series airplanes of U.S. registry would be affected 
by this proposed AD, that it would take approximately 13 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 total cost 
impact of the proposed AD on U.S. operators is estimated to be $67,080, 
or $780 per airplane, per inspection cycle.
    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 97-NM-106-AD.

    Applicability: All Model SD3-60 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 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 detect and correct corrosion and/or wear of the top and 
bottom shear decks of the left and right stub wings in the area of 
the forward pintle pin of the main landing gear (MLG), which could 
result in failure of the MLG to extend or retract, accomplish the 
following:
    (a) Within 90 days after the effective date of this AD, conduct 
an inspection for corrosion of the top and bottom shear decks of the 
left and right stub wings in the area of the forward pintle pin of 
the MLG, and measure the retaining pin holes of the pintle pin for 
wear; in accordance with Part A. of the Accomplishment Instructions 
of Short Brothers Service Bulletin SD360-53-42, dated September 1996 
(for Model SD3-60 series airplanes), or Short Brothers Service 
Bulletin SD3-60 SHERPA-53-3, dated November 4, 1997 (for Model SD3-
60 SHERPA series airplanes), as applicable.
    (1) If no corrosion, wear, or discrepancy of the measurement of 
the holes for the retaining pin of the pintle pin is found, repeat 
the inspection required by paragraph (a) of this AD thereafter at 
intervals not to exceed 6 months.
    (2) If any corrosion, wear, or measurement of the holes for the 
retaining pin of the pintle pin is found that is within the limits 
specified in Part A. of the Accomplishment Instructions of the 
applicable service bulletin, prior to further flight, repair the 
discrepancy in accordance with the applicable service bulletin. 
Thereafter, repeat the inspection required by paragraph (a) of this 
AD at intervals not to exceed 6 months.
    (3) If any corrosion, wear, or measurement of the holes for the 
retaining pin of the pintle pin is found that is beyond the limits 
specified in Part A. of the Accomplishment Instructions of the 
applicable service bulletin, prior to further flight, perform the 
actions required by paragraph (a)(3)(i) and (a)(3)(ii) of this AD.
    (i) Remove the corrosion and install bushings on the upper and 
lower shear webs in the retaining pin holes for the pintle pin in 
accordance with Part B. (left MLG) and/or Part C. (right MLG), as 
applicable, of the Accomplishment Instructions of the applicable 
service bulletin.
    (ii) Perform a visual inspection of the pintle pin and the 
sleeve for any discrepancy, in accordance with Part B. and/or Part 
C., as applicable, of the Accomplishment Instructions of the 
applicable service bulletin.

[[Page 39771]]

    (A) If no discrepancy is detected, the pintle pin and the sleeve 
of the pintle pin may be returned to service.
    (B) If any discrepancy of the pintle pin and sleeve is detected, 
prior to further flight, repair the pintle pin and sleeve in 
accordance with a method approved by the Manager, International 
Branch, ANM-116, FAA, Transport Airplane Directorate.
    (b) Removal of corrosion and installation of bushings in 
accordance with Part B. and/or Part C., as applicable, of the 
Accomplishment Instructions of Short Brothers Service Bulletin 
SD360-53-42, dated September 1996 (for Model SD3-60 series 
airplanes), or Short Brothers Service Bulletin SD3-60 SHERPA-53-3, 
dated November 4, 1997 (for Model SD3-60 SHERPA series airplanes), 
as applicable, constitutes terminating action for the repetitive 
inspection requirements of this AD.
    (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. 
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.

    (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 British 
airworthiness directives 005-09-96 and 005-11-97.

    Issued in Renton, Washington, on July 20, 1998.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-19778 Filed 7-23-98; 8:45 am]
BILLING CODE 4910-13-U
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