AD 2002-03-13

This amendment adopts a new airworthiness directive (AD), applicable to all Short Brothers Model SD3-60, SD3-60 SHERPA, and SD3-SHERPA series airplanes, that requires a one-time inspection of the wiring harness and power cables of the heated windshield to detect inadequate clearance, inadequate support, or chafing. This amendment also requires corrective action (including re-routing for adequate clearance or replacing damaged cables, as applicable), if necessary. The actions specified by this AD are intended to prevent chafing or damage of the power cables of the heated windshield, which could cause arcing and result in smoke and fire in the cockpit. This action is intended to address the identified unsafe condition.

Final rule.

2002-03-13 Short Brothers PLC: Amendment 39-12654. Docket 2001-NM-143-AD.

Applicability: All Model SD3-60, SD3-60 SHERPA, and SD3-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 (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 prevent chafing or damage of the power cables of the heated windshield, which could cause arcing and result in smoke and fire in the cockpit, accomplish the following:

Inspection and Corrective Action

(a) Within 90 days after the effective date of this AD: Perform a general visual inspection of the wiring harness and power cables of the heated windshield to detect inadequate clearance between the cables and the flight instruments, and to ensure that the harness is securely supported and no chafing of the protective cover on the cables is evident, in accordance with Short Brothers Service Bulletin SD3 SHERPA-30-2 (for Model SD3 SHERPA series airplanes), SD360 SHERPA-30-2 (for Model SD3-60 SHERPA series airplanes), or SD360-30-26 (for Model SD3-60 series airplanes); all dated April 2, 2001; as applicable. If no evidence of chafing is found and clearance and support of the power cables is adequate, no further action is needed.

Note 2: For the purposes of this AD, a general visual inspection is defined as: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked."

(1) If no evidence of chafing is found, but clearance or support of the harness is inadequate: Prior to further flight, re-route the power cable for adequate clearance or provide additional support of the cable harness, as applicable, in accordance with Short Brothers Service Bulletin SD3 SHERPA-30-2 (for Model SD3 SHERPA series airplanes), SD360 SHERPA-30-2 (for Model SD3-60 SHERPA series airplanes), or SD360-30-26 (for Model SD3-60 series airplanes); all dated April 2, 2001; as applicable.

(2) If evidence of chafing is found, but there is no damage to the outer nylon protective cover resulting in exposure of the glass fiber braid: Prior to further flight, re-route the power cables for adequate clearance, in accordance with Short Brothers Service Bulletin SD3 SHERPA-30-2 (for Model SD3 SHERPA series airplanes), SD360 SHERPA-30-2 (for Model SD3-60 SHERPA series airplanes), or SD360-30-26 (for Model SD3-60 series airplanes); all dated April 2, 2001; as applicable.

(3) If evidence of chafing is found, and there is damage to the outer nylon protective cover resulting in exposure of the glass fiber braid: Prior to further flight, replace the damaged power cable with a new cable, in accordance with Short Brothers Service Bulletin SD3 SHERPA-30-2 (for Model SD3 SHERPA series airplanes), SD360 SHERPA-30-2 (for Model SD3-60 SHERPA series airplanes), or SD360-30-26 (for Model SD3-60 series airplanes); all dated April 2, 2001; as applicable.

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.

Incorporation by Reference

(d) The actions shall be done in accordance with Short Brothers Service Bulletin SD3 SHERPA-30-2, dated April 2, 2001; Short Brothers Service Bulletin SD360 SHERPA-30-2, dated April 2, 2001; and Short Brothers Service Bulletin SD360-30-26, dated April 2, 2001; as applicable. 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 directive 001-04-2001.

Effective Date

(e) This amendment becomes effective on March 27, 2002.

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 SD3-60, SD3-60 SHERPA, and SD3-SHERPA series airplanes was published in the Federal Register on November 23, 2001 (66 FR 58680). That action proposed to require a one-time inspection of the two power cables to the heated windshield to detect inadequate clearance, chafing, and inadequate support. The action also proposed to require corrective action, if necessary, including increasing the clearance, providing additional support, re-routing, and replacing power cables, as applicable.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Explanation of Changes to Final Rule

The statement of unsafe condition in the"Summary" section and subsequent sections of this AD have been changed for clarification to include a reference to the wiring harness of the power cables and to clarify certain wording.

Paragraph (a) of the proposed rule specifies a general visual inspection of the power cables to the heated windshield to detect inadequate clearance, chafing, and inadequate support. However, paragraph (a) of the proposed rule does not make clear that the inspection includes inspecting the wiring harness and ensuring that the harness is securely supported. Therefore, for clarification, we have changed paragraph (a) of this final rule to require a general visual inspection of the wiring harness and power cables of the heated windshield to detect inadequate clearance between the cables and the flight instruments, and to ensure that the harness is securely supported and no chafing of the protective cover on the cables is evident.

In addition, we have changed paragraphs (b), (c), and (d) of the proposed rule to paragraphs (a)(1), (a)(2), and (a)(3) in this final rule, as they are subparagraphs of paragraph (a), and we have clarified certain wording in those paragraphs. We find that these changes do not expand the scope of the proposed AD but merely provide clarification of the requirements of this AD.

Conclusion

After careful review of the available data, 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 78 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required inspection, 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 $4,680, or $60 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. 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 adopted herein will 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 final rule does not have federalism implications under Executive Order 13132.

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 DIRECTIVES1. 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: