[Federal Register Volume 62, Number 193 (Monday, October 6, 1997)]
[Proposed Rules]
[Pages 52053-52055]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-26377]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-106-AD]


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 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. 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 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 November 5, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
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 a.m. and 3 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: Gary Lium, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1112; fax (425) 227-1149.

[[Page 52054]]

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-103, Attention: Rules 
Docket No. 97-NM-106-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 it has received 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 main landing 
gear (MLG). The corrosion and/or wear was attributed to migration of 
the retaining pin of the forward pintle pin of the MLG due to loss of 
the retaining pin's circlip. 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 detected and corrected in a 
timely manner, could result in failure of the MLG to extend or retract.

Explanation of Relevant Service Information

    Short Brothers has issued Service Bulletin SD360-53-42, dated 
September 1996, 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 005-09-96 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, the 
proposed AD would require repetitive inspections 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, and 
repair of any corrosion and/or wear. Those actions are required to be 
accomplished in accordance with the service bulletin described 
previously.

Differences Between the Proposal and the related CAA AD

    Operators should note that for certain depths of corrosion and/or 
wear detected that require an inspection of the pintle pin and sleeve, 
this AD requires the repair of any discrepancy of the pintle pin or 
sleeve to be accomplished 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 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 $68,640, or $780 per airplane.
    The total 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:

[[Page 52055]]

    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 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 
otherwise 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 use the authority 
provided in paragraph (c) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the main landing gear (MLG) to extend or 
retract due to corrosion and/or wear of the left and right stub 
wings in the area of the forward pintle pin of the MLG, 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.
    (1) 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 
service bulletin, prior to further flight, repair the discrepancy in 
accordance with the service bulletin. Thereafter, repeat the 
inspection required by paragraph (a) of this AD 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 beyond the limits 
specified in Part A. of the Accomplishment Instructions of the 
service bulletin, prior to further flight, perform the actions 
required by paragraph (a)(2)(i) and (a)(2)(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 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 service 
bulletin.
    (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, Standardization 
Branch, ANM-113, 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, 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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    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 directive 005-09-96.

    Issued in Renton, Wash., on September 30, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-26377 Filed 10-3-97; 8:45 am]
BILLING CODE 4910-13-U