E6-5357. Airworthiness Directives; Short Brothers Model SD3 Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to all Short Brothers Model SD3 airplanes. The original NPRM would have required installing additional fuel tank bonding jumpers, performing an in-place resistance check of the float switches, inspecting certain internal components of the fuel tanks, and performing related corrective actions if necessary. The original NPRM would have also required revisions to the Airworthiness Limitations section of the Instructions for Continued Airworthiness, and to the airplane flight manual procedures for operation during icing conditions and fuel system failures. The original NPRM resulted from fuel system reviews conducted by the manufacturer. This action revises the original NPRM by adding service information. We are proposing this supplemental NPRM to prevent ignition sources inside the fuel tanks, which could lead to fire or explosion.

DATES:

We must receive comments on this supplemental NPRM by May 8, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this supplemental NPRM.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Short Brothers, Airworthiness & Engineering Quality, P.O. Box 241, Airport Road, Belfast BT3 9DZ, Northern Ireland, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT:

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

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this supplemental NPRM. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2005-23173; Directorate Identifier 2005-NM-190-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this supplemental NPRM. We will consider all comments received by the closing date and may amend this supplemental NPRM in light of those comments.

We will post all comments submitted, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this supplemental NPRM. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level in the Nassif Building at the DOT street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

We proposed to amend 14 CFR part 39 with a notice of proposed rulemaking (NPRM) for an airworthiness directive (AD) (the “original NPRM”). The original NPRM applies to all Short Brothers Model SD3 airplanes. The original NPRM was published in the Federal Register on December 5, 2005 (70 FR 72406). The original NPRM proposed to require installing additional fuel tank bonding jumpers, performing an in-place resistance check of the float switches, inspecting certain internal components of the fuel tanks, and performing related corrective actions if necessary. The original NPRM also proposed to require revisions to the Airworthiness Limitations section of the Instructions for Continued Airworthiness, and to the airplane flight manual procedures for operation during icing conditions and fuel system failures.

Since the original NPRM was issued, Short Brothers has issued three additional temporary revisions (TRs) to the airworthiness limitations section of the aircraft maintenance manuals (AMMs) of the affected airplanes. In addition, we have been informed that a fourth TR was issued that was not addressed by British airworthiness directive G-004-0021, dated August 25, 2004, which was referenced as the parallel British airworthiness directive in the original NPRM.

Relevant Service Information

Short Brothers has issued Service Bulletins SD3 SHERPA-28-2, SD360 SHERPA-28-3, SD330-28-37, and SD360-28-23; all dated June 2004. The service bulletins describe procedures for installing additional bonding jumpers between the vent pipes of both fuel tanks and the airplane structure; for performing an in-place resistance check of the fuel tank float switches; for inspecting the condition of certain sensor cables and cable supports inside the fuel tanks; for inspecting the integrity of the existing bonding of certain vent pipes inside the forward fuel tank; and for performing applicable corrective actions. Corrective actions include replacing defective float switches with new, reconditioned, or serviceable float switches, and repairing damaged sensor cables, cable supports, and existing vent pipe bonding.

Short Brothers has issued Advance Amendment Bulletin 1/2004, dated July 13, 2004, applicable to Shorts airplane flight manuals having Doc. Nos. SB.4.3, SB.4.6, SB.4.8, SB.5.2, SB.6.2, SBH.3.2, SBH.3.3, SBH.3.6, SBH.3.7, SBH.3.8, and SBH.3.9. The advance amendment bulletin describes revisions needed to meet the requirements of FAA SFAR 88 and/or CAA Airworthiness Notice AN55; the revisions affect sections of the flight manuals applicable to operation during icing conditions and fuel system failures.

Short Brothers has issued TRs to the airworthiness limitations section of the aircraft maintenance manuals (AMM) of the affected airplanes, as shown in the following table. The TRs address airworthiness limitations to certain components of the fuel tank system installations.

AMM Temporary Revisions

Airplane model	Temporary revision	Dated	To AMM
SD3-30	TR330-AMM-13	June 21, 2004	SD3-30 AMM.
SD3-30	TR330-AMM-14	June 21, 2004	SD3-30 AMM.
SD3-60	TR360-AMM-33	July 27, 2004	SD3-60 AMM.
SD3-60	TR360-AMM-34	July 27, 2004	SD3-60 AMM.
SD3-60 SHERPA	TRSD360S-AMM-14	July 29, 2004	SD3-60 SHERPA AMM.
SD3-60 SHERPA	TRSD360S-AMM-15	July 29, 2004	SD3-60 SHERPA AMM.
SD3-SHERPA	TRSD3S-AMM-15	July 28, 2004	SD3-SHERPA AMM.
SD3-SHERPA	TRSD3S-AMM-16	July 28, 2004	SD3-SHERPA AMM.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. The CAA mandated the service information and issued British airworthiness directive G-2004-0021 R1, dated September 15, 2004, to ensure the continued airworthiness of these airplanes in the United Kingdom. Paragraph (j) of this supplemental NPRM has been revised accordingly.

Comments

We provided the public the opportunity to participate in the development of this AD. We received no comments on the original NPRM or on the determination of the cost to the public.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

The changes discussed above expand the scope of the original NPRM; therefore, we have determined that it is necessary to reopen the comment period to provide additional opportunity for public comment on this proposed AD. Therefore, we are issuing this supplemental NPRM, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Difference Between the Proposed AD and Service Information.”

Difference Between Proposed AD and Service Information

The service bulletins specify to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions using a method that we or the CAA (or its delegated agent) approve. In light of the type of repair that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this proposed AD, a repair we or the CAA approve would be acceptable for compliance with this proposed AD.

Clarification of Inspection Terminology

In this proposed AD, the “visual inspection” specified in the Shorts service bulletins is referred to as a “general visual inspection.” We have included the definition for a general visual inspection in a note in the proposed AD.

Change to Work Hour Rate

After the original NPRM was issued, we reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $65 per work hour to $80 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Costs of Compliance

This supplemental NPRM would affect about 54 airplanes of U.S. registry. The average labor rate is estimated to be $80 per work hour.

The proposed revisions to the AFM and AMM would take about 1 work hour per airplane. Based on these figures, the estimated cost of the proposed revisions for U.S. operators is $4,320, or $80 per airplane.

The proposed resistance check, inspections, and jumper installations, would take about 40 work hours per airplane. Required parts would cost about $10 per airplane. Based on these figures, the estimated cost of these proposed actions for U.S. operators is $173,340, or $3,210 per airplane.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the 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. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this supplemental NPRM and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Short Brothers PLC: Docket No. FAA-2005-23173; Directorate Identifier 2005-NM-190-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by May 8, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all Shorts Model SD3-60 SHERPA, SD3-SHERPA, SD3-30, and SD3-60 airplanes, certificated in any category.

Note 1:

This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the inspections described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (i) of this AD. The request should include a description of changes to the required inspections that will ensure the continued damage tolerance of the affected structure. The FAA has provided guidance for this determination in Advisory Circular (AC) 25-1529.

Unsafe Condition

(d) This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent ignition sources inside the fuel tanks, which could lead to fire or explosion.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Revision of Airplane Flight Manual (AFM)

(f) Within 30 days after the effective date of this AD, revise the Limitations and Normal Procedures sections of the AFMs as specified in Table 1 of this AD to include the information in Shorts Advance Amendment Bulletin 1/2004, “Introduction of Changes to Meet the Requirements of FAA SFAR 88 and/or UK CAA Airworthiness Notice AN55,” dated July 13, 2004, as specified in the advance amendment bulletin. This advance amendment bulletin addresses operation during icing conditions and fuel system failures. Thereafter, operate the airplane according to the limitations and procedures in the advance amendment bulletin.

Note 2:

The requirements of paragraph (f) of this AD may be done by inserting a copy of the advance amendment bulletin into the AFM. When this advance amendment bulletin has been included in general revisions of the AFM, the general revisions may be inserted into the AFM and the advance amendment bulletin may be removed, provided the relevant information in the general revision is identical to that in the advance amendment bulletin.

Table 1.—AFM Revisions

Airplane model	AFM documents to be revised
SD3-30	SBH.3.2, SBH.3.3, SBH.3.6, SBH.3.7, SBH.3.8, and SBH.3.9.
SD3-60	SB.4.3, SB.4.6, and SB.4.8.
SD3-60 SHERPA	SB.5.2.
SD3-SHERPA	SB.6.2.

Revision of Airworthiness Limitation (AWL) Section

(g) Within 180 days after the effective date of this AD: Revise the AWL section of the Instructions for Continued Airworthiness by incorporating airplane maintenance manual (AMM) sections 5-20-01 and 5-20-02 as introduced by the Shorts temporary revisions (TR) specified in Table 2 of this AD into the AWL section of the AMMs for the airplane models specified in Table 2. Thereafter, except as provided by paragraph (i) of this AD, no alternative structural inspection intervals may be approved for the longitudinal skin joints in the fuselage pressure shell.

Note 3:

The requirements of paragraph (g) of this AD may be done by inserting a copy of the applicable TR into the applicable AMM. When the TR has been included in general revisions of the AMM, the general revisions may be inserted in the AMM and the TR may be removed, provided the relevant information in the general revision is identical to that in the TR.

Table 2.—AMM Temporary Revisions

Airplane model	Temporary revision	Dated	To AMM
SD3-30	TR330-AMM-13	June 21, 2004	SD3-30 AMM.
SD3-30	TR330-AMM-14	June 21, 2004	SD3-30 AMM.
SD3-60	TR360-AMM-33	July 27, 2004	SD3-60 AMM.
SD3-60	TR360-AMM-34	July 27, 2004	SD3-60 AMM.
SD3-60 SHERPA	TRSD360S-AMM-14	July 29, 2004	SD3-60 SHERPA AMM.
SD3-60 SHERPA	TRSD360S-AMM-15	July 29, 2004	SD3-60 SHERPA AMM.
SD3-SHERPA	TRSD3S-AMM-15	July 28, 2004	SD3-SHERPA AMM.
SD3-SHERPA	TRSD3S-AMM-16	July 28, 2004	SD3-SHERPA AMM.

Resistance Check, Inspection, and Jumper Installation

(h) Within 180 days after the effective date of this AD: Perform the insulation resistance check, general visual inspections, and bonding jumper wire installations; in accordance with Shorts Service Bulletin SD330-28-37, SD360-28-23, SD360 SHERPA-28-3, or SD3 SHERPA-28-2; all dated June 2004; as applicable. If any defect or damage is discovered during any inspection or check required by this AD, before further flight, repair the defect or damage using a method approved by either the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or the Civil Aviation Authority (CAA) (or its delegated agent).

Note 4:

For the purposes of this AD, a general visual inspection is: “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 from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight 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.”

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Related Information

(j) British airworthiness directive G-2004-0021 R1, dated September 15, 2004, also addresses the subject of this AD.

Issued in Renton, Washington, on April 4, 2006.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.