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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-NM-141-AD; Amendment 39-8850; AD 94-06-02]

Airworthiness Directives; Short Brothers PLC Model SD3-30, SD3-

60, and SD3-SHERPA Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive

(AD), applicable to certain Short Brothers PLC Model SD3-30, SD3-60,

and SD3-SHERPA series airplanes, that currently requires an inspection

to detect corrosion on the distance piece associated with the wing

strut pick up on the stub wing, and repair of corroded parts. This

amendment requires repetitive inspections to detect corrosion of

repaired or reworked distance pieces and adjacent side plates; and

provides a terminating action for the repetitive inspections. This

amendment is prompted by reports of corrosion on the distance pieces

and adjacent side plates of the wing strut pick up. The actions

specified by this AD are intended to prevent failure of the distance

piece and adjacent side plates, which could result in reduced strength

of the wing strut attachment to the stub wing on the fuselage and,

subsequently, reduced structural strength of the main wing.

DATES: Effective May 16, 1994.

The incorporation by reference of Shorts Service Bulletin SD3-

SHERPA-53-1, Revision 1, dated May 1993; Shorts Service Bulletin SD360-

53-38, Revision 1, dated May 1993; Shorts Service Bulletin SD330-53-65,

Revision 1, dated May 1993; Shorts Service Bulletin SD3 SHERPA-53-2,

dated July 1993; Shorts Service Bulletin SD360-53-39, dated June 11,

1993; and Shorts Service Bulletin SD330-53-66, dated July 1993; as

listed in the regulations, is approved by the Director of the Federal

Register as of May 16, 1994.

The incorporation by reference of certain other publications listed

in the regulations was approved by the Director of the Federal Register

as of May 27, 1993 (58 FR 27928, May 12, 1993).

ADDRESSES: The service information referenced in this AD may be

obtained from Short Brothers PLC, 2011 Crystal Drive, Suite 713,

Arlington, Virginia 22202-3719. 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: William Schroeder, Aerospace Engineer,

Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)

227-2148; fax (206) 227-1320.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations by superseding AD 93-09-08, Amendment 39-8574 (58

FR 27928, May 12, 1993), which is applicable to certain Short Brothers

PLC Model SD3-30, SD3-60, and SD3-SHERPA series airplanes, was

published in the Federal Register on November 5, 1993 (58 FR 58992).

The action proposed to supersede AD 93-09-08 to continue to require a

one-time inspection to detect corrosion on the distance piece

associated with the wing strut pick up on the stub wing, and repair or

rework of corroded parts. The AD also proposed to require repetitive

inspections to detect corrosion of repaired or reworked original

equipment type distance pieces (with pockets) and adjacent side plates.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the single comment received.

The commenter supports the proposed rule.

After careful review of the available data, including the comment

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule as proposed.

The FAA estimates that 106 airplanes of U.S. registry will be

affected by this AD. The currently required one-time inspection action

requires approximately 5 work hours per airplane to accomplish the

actions, at an average labor rate of $55 per work hour. Based on these

figures, the total cost impact of that action on U.S. operators is

estimated to be $29,150, or $275 per airplane.

For operators who replace or repair a distance piece, this AD will

require that repetitive inspections of that distance piece be

performed. Such inspections will require approximately 5 work hours to

accomplish, at an average labor charge of $55 per work hour. Based on

these figures, the total cost impact of the repetitive inspections that

will be required of these operators will be $275 per airplane per

inspection cycle.

Should an operator elect to accomplish the optional terminating

action that will be provided by this AD action, the number of hours

required to accomplish it will be approximately 80 per airplane, at an

average labor charge of $55 per work hour. The cost of required parts

will be approximately $2,600 per airplane. Based on these figures, the

total cost impact of the optional terminating action on U.S. operators

will be $7,000 per airplane.

The total 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.

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 14 CFR part

39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing amendment 39-8574 (58 FR

27928, May 12, 1993), and by adding a new airworthiness directive (AD),

amendment 39-8850, to read as follows:

94-06-02 Short Brothers PLC: Amendment 39-8850. Docket 93-NM-141-AD.

Supersedes AD 93-09-08, Amendment 39-8574.

Applicability: Model SD3-SHERPA series airplanes, serial numbers

SH3201 through SH3216 inclusive; all Model SD3-60 series airplanes;

and all Model SD3-30 series airplanes; certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent failure of the distance piece and adjacent side

plates, which could result in reduced strength of the wing strut

attachment to the stub wing on the fuselage and, subsequently,

reduced structural strength of the main wing, accomplish the

following:

(a) Within 30 days after May 27, 1993 (the effective date of AD

93-09-08, Amendment 39-8574), perform a detailed visual inspection

to detect corrosion in the pockets on the horizontal leg of the

distance piece associated with the wing strut pick up on the left-

and right-stub wings, in accordance with Shorts Service Bulletin SD3

SHERPA-53-1, dated March 29, 1993, or Revision 1, dated May 1993

(for Model SD3-SHERPA series airplanes); Shorts Service Bulletin

SD360-53-38, dated March 25, 1993, or Revision 1, dated May 1993

(for Model SD3-60 series airplanes); or Shorts Service Bulletin

SD330-53-65, dated March 29, 1993, or Revision 1, dated May 1993

(for Model SD3-30 series airplanes); as applicable.

(1) If any corrosion is detected that is within the limits

specified in the applicable service bulletin, prior to further

flight, repair or rework the corroded components in accordance with

the applicable service bulletin.

(2) If any corrosion is detected that is outside the limits

specified in the applicable service bulletin, prior to further

flight, accomplish either paragraph (a)(2)(i) or (a)(2)(ii) of this

AD:

(i) Replace any corroded distance piece with a new, improved

distance piece (without pockets), and repair or replace the adjacent

side plates, as necessary, in accordance with the applicable service

bulletin. Or

(ii) Repair or rework the corroded components in accordance with

a method approved by the Manager, Standardization Branch, ANM-113,

FAA, Transport Airplane Directorate.

(3) If no corrosion is detected, accomplish the requirements of

paragraph (b) of this AD.

(b) Within 10 days after accomplishing the initial inspection

required by paragraph (a)(1) of this AD, submit a report of all

inspection findings, including nil defects, to Short Brothers PLC.

Information collection requirements contained in this regulation

have been approved by the Office of Management and Budget (OMB)

under the provisions of the Paperwork Reduction Act of 1980 (44

U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-

0056.

(c) For those airplanes on which the distance piece has been

reworked or repaired in accordance with the requirements of

paragraph (a) of this AD: Within 90 days after the effective date of

this AD or within the next 600 hours time-in-service after the

effective date of this AD, whichever occurs earlier, and thereafter

at intervals not to exceed 90 days or 600 hours time-in-service,

whichever occurs earlier, repeat the inspection of the distance

piece and adjacent side plates in accordance with the requirements

of paragraph (a) of this AD.

(d) Replacement of the existing distance piece and/or adjacent

side plates with new distance pieces (without pockets) and/or

adjacent side plates in accordance with Short Brothers Service

Bulletins SD3 SHERPA-53-2, dated July 1993 (for Model SD3-SHERPA

series airplanes); SD360-53-39, dated June 11, 1993 (for Model SD3-

60 series airplanes); or SD330-53-66, dated July 1993 (for Model

SD3-30 series airplanes); as applicable; constitutes terminating

action for the repetitive inspection requirement of paragraph (c) of

this AD.

(e) 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, Standardizaton

Branch, ANM-113.

Note: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Standardization Branch, ANM-113.

(f) Special flight permits 1may be issued in accordance with

Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the

airplane to a location where the requirements of this AD can be

accomplished.

(g) The actions shall be done in accordance with Shorts Service

Bulletin SD3 SHERPA-53-1, Revision 1, dated May 1993; Shorts Service

Bulletin SD360-53-38, Revision 1, dated May 1993; Shorts Service

Bulletin SD330-53-65, Revision 1, dated May 1993; Shorts Service

Bulletin SD3 SHERPA-53-2, dated July 1993; Shorts Service Bulletin

SD360-53-39, dated June 11, 1993, or Shorts Service Bulletin SD330-

53-66, dated July 1993, as applicable. The following Shorts service

bulletins contain the specified effective pages:

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Service bulletin Revision level Date shown on

referenced and date Page No. shown on page page

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SD3 SHERPA-53-1, 1, 3-7 1............. May 1993.

Revision 1, May 1993. 2 Original...... March 1993.

SD360-53-38, Revision 1, 3-7 1............. May 1993.

1, May 1993. 2 Original...... March 1993.

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This incorporation by reference is approved by the Director of

the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR

part 51. Certain other actions shall be done in accordance with

Shorts Service Bulletin SD3 SHERPA-53-1, dated March 29, 1993;

Shorts Service Bulletin SD360-53-38, dated March 25, 1993; and

Shorts Service Bulletin SD330-53-65, dated March 29, 1993. The

incorporation by reference of these documents was approved

previously by the Director of the Federal Register in accordance

with 5 U.S.C. 552(a) and 1 CFR Part 51 as of May 27, 1993 (58 FR

27928, May 12, 1993). Copies may be obtained from Short Brothers

PLC, 2011 Crystal Drive, Suite 713, Arlington, Virginia 22202-3719.

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.

(h) This amendment becomes effective on May 16, 1994.

Issued in Renton, Washington, on March 4, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-5556 Filed 4-13-94; 8:45 am]

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