01-20809. Airworthiness Directives; Short Brothers Model SD3 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Short Brothers Model SD3 series airplanes. This proposal would require an inspection to find discrepancies of the hydraulic pipelines of the 7P panel and adjacent electrical wiring harnesses, and corrective action, if necessary. This action is necessary to find and fix such discrepancies, which could result in electrical arcing between the hydraulic lines and adjacent wiring and a potential fire. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by September 17, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-175-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. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-175-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

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:

Todd Thompson, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

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 action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-175-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. 2001-NM-175-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 certain Short Brothers Model SD3 series airplanes. The CAA advises that investigation of these airplanes by the manufacturer revealed that, in certain areas, clearance between the hydraulic lines and electrical wiring must be ensured. Inadequate clearance may lead to chafing of the cables and damage to the hydraulic pipelines. This condition, if not corrected, could result in electrical arcing between the hydraulic lines and adjacent wiring and a potential fire.

Explanation of Relevant Service Information

The manufacturer has issued Shorts Service Bulletins SD3 SHERPA-24-5; SD330-24-29; SD360-24-25; and SD360 SHERPA-24-4; all dated April 30, 2001. The service bulletins describe procedures for an inspection to find discrepancies of the hydraulic pipelines of the 7P panel and adjacent electrical wiring harnesses, and corrective action, if necessary. The discrepancies include inadequate clearance between certain hydraulic pipelines of the 7P panel and adjacent electrical wiring harnesses, chafing between the electrical wires and hydraulic line, or damage to the hydraulic pipelines or wiring harnesses. The corrective action includes rerouting for adequate clearance, clipping or sleeving of the wiring harness and/or replacement of damaged pipelines with new pipelines. Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition.

The CAA classified these service bulletins as mandatory and issued British airworthiness directives 006-04-2001, 007-04-2001, 008-04-2001, and 009-04-2001, in order to assure the continued airworthiness of these airplanes in the United Kingdom.

FAA's Conclusions

These airplane models are manufactured in the United Kingdom and are type certificated for operation in the United States under the provisions of section 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, except as discussed below.

Difference Between This Proposed AD and Service Bulletins

The referenced service bulletins do not define the type of inspection to be used to find discrepancies of the hydraulic pipelines of the 7P panel and adjacent electrical wiring harnesses. However, the FAA has determined that a detailed visual inspection would be required to find such discrepancies. A note has been added that defines a detailed visual inspection.

Cost Impact

The FAA estimates that 75 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to accomplish the proposed inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $4,500, or $60 per airplane.

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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would not have a substantial direct effect 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, it is determined that this proposal would not have federalism implications under Executive Order 13132.

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.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Short Brothers, PLC: Docket 2001-NM-175-AD.

Applicability: This AD applies to the airplanes listed in Table 1 of this AD, certificated in any category:

Table 1.—Applicability

Short Brothers model	Description
SD3-SHERPA series airplanes	On which Short Brothers Modification K2239 has not been accomplished.
SD3-60 SHERPA series airplanes	On which Short Brothers Modification K6109 has not been accomplished.
SD3-60 series airplanes	On which Short Brothers Modification A8684 has not been accomplished.
SD3-30 series airplanes	On which Short Brothers Modification P4810 has not been accomplished.

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 request approval for an alternative method of compliance in accordance with paragraph (b) 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 find and fix discrepancies of the hydraulic pipelines of the 7P panel and adjacent electrical wiring harnesses, which could result in electrical arcing between the hydraulic lines and adjacent wiring and a potential fire, accomplish the following:

Inspection/Corrective Action

(a) Within 90 days after the effective date of this AD, do a detailed visual inspection to find discrepancies (inadequate clearance, chafing, or damage) of the hydraulic pipelines of the 7P panel and adjacent electrical wiring harnesses, per the Accomplishment Instructions of Shorts Service Bulletins SD3 SHERPA-24-5, SD330-24-29, SD360-24-25, or SD360 SHERPA-24-4, all dated April 30, 2001; as applicable. Before further flight, fix any discrepancies found, per the applicable service bulletin.

Note 2:

For the purposes of this AD, a detailed visual inspection is defined 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 lighting 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.”

Alternative Methods of Compliance

(b) 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, Transport Airplane Directorate, FAA. 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

(c) 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.

Note 4:

The subject of this AD is addressed in British airworthiness directives 006-04-2001, 007-04-2001, 008-04-2001, and 009-04-2001.

Issued in Renton, Washington, on August 13, 2001.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.