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Airworthiness Directives; Bell Helicopter Textron Model 212, 412, and 412EP Helicopters

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) for the specified Bell Helicopter Textron (Bell) model helicopters modified with Aeronautical Accessories, Inc. (AAI), Supplemental Type Certificate (STC) SH2820SO or that have the affected AAI Parts Manufacturer Approval (PMA) parts installed. This action requires inspecting a certain part-numbered reservoir assembly adapter (adapter) for the counter bore depth (dimension D). If the dimension D of the adapter exceeds .860 inch, before further flight, this AD requires replacing the reservoir assembly and adapter with airworthy parts. This amendment is prompted by a report of a rupture of an adapter during nitrogen charging because of inadequate wall thickness for the operating pressures. The actions specified in this AD are intended to prevent the rupture of an adapter, uncontrolled jetting of pressurized gas from the nitrogen bottle, and subsequent injury to occupants or damage to the helicopter.

DATES:

Effective October 28, 2005.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 28, 2005.

Comments for inclusion in the Rules Docket must be received on or before December 12, 2005.

ADDRESSES:

Use one of the following addresses to submit comments on this AD:

  • 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: (202) 493-2251; or
  • 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.

You may get the service information identified in this AD from Aeronautical Accessories, Inc., P. O. Box 3689, Bristol, Tennessee 37625-3689.

Examining the Docket

You may examine the docket that contains the AD, any comments, and other information on the Internet at http://dms.dot.gov, or in person at the Docket Management System (DMS) Docket Offices between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Marc Belhumeur, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort Worth, Texas 76193-0170, telephone (817) 222-5177, fax (817) 222-5783.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

This amendment adopts a new AD for the specified Bell model helicopters modified with an AAI STC SH2820SO or with AAI PMA reservoir assembly or adapter installed. This action requires a one-time inspection of the adapter counter bore depth. If the counter bore depth dimension exceeds .860 inch, this AD requires replacing the reservoir assembly and adapter with airworthy parts before further flight. This amendment is prompted by a report of a rupture of an adapter on a Bell Model 412 helicopter during nitrogen charging. The assembly adapter ruptured, and the pressurized nitrogen gas jetted out of the nitrogen bottle in the helicopter and caused significant damage. The rupture occurred because the adapter had inadequate fracture strength because the counter bore was too large, which produced insufficient wall thickness for the operating pressures. This condition, if not corrected, could result in rupture of an adapter, uncontrolled jetting of pressurized gas from the nitrogen bottle, and subsequent injury to occupants or damage to the helicopter.

We have reviewed AAI Alert Service Bulletin No. AA-05005, Revision A, dated June 27, 2005 (ASB), for Bell Model 212/412/412EP helicopters with the reservoir assembly, part number (P/N) 212-372-050, and the adapter, P/N 212-371-002, installed. The ASB describes procedures for discharging the floatation system, inspecting the counter bore depth of the adapter (dimension D), recharging the floatation system, and specifies replacing the assembly and adapter if the dimension D exceeds .860. The ASB states that the adapter located between the neck of the reservoir assembly and the inflation valve may have been manufactured incorrectly resulting in a weakened condition that could lead to the rupture of the adapter fitting while under pressure.

This unsafe condition is likely to exist or develop on other helicopters of the same type designs modified with AAI STC SH2820SO or that has the affected PMA P/N installed. Therefore, this AD is being issued to prevent the rupture of an adapter, uncontrolled jetting of pressurized gas from the nitrogen bottle, and subsequent injury to occupants or damage to the helicopter. This AD requires the following:

  • Within 24 hours time-in-service (TIS) or before the next emergency floatation supply bottle nitrogen charging, whichever occurs first, for the reservoir assembly, P/N 212-372-050, and the adapter, P/N 212-371-002, do the following:
  • Discharge the nitrogen from the reservoir assembly.
  • Remove the valve assembly and air line from the adapter, and inspect the dimension D.
  • If the dimension D does not exceed .860 inch, recharge the floatation system.
  • If the dimension D exceeds .860 inch, before further flight, replace the reservoir assembly and the adapter with airworthy parts.

Accomplish the actions in accordance with the specified portions of the service bulletin described previously. The short compliance time involved is required because the previously described critical unsafe condition can damage the helicopter and injure its occupants as well as render the floatation system inoperative. Therefore, inspecting the counter bore depth of the adapter is required within 24 hours TIS or before the next emergency floatation supply bottle nitrogen charging, whichever occurs first. Because this is a very short compliance time, this AD must be issued immediately.

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. Start Printed Page 59637

We estimate that this AD will affect 100 helicopters. Discharging the system, inspecting the dimension D of the adapter, replacing the reservoir assembly and adapter, and recharging the system will take about 2 work hours at an average labor rate of $65 per work hour. Required parts will cost about $5095 to replace the reservoir assembly and adapter per helicopter. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $522,500, assuming the reservoir assembly and adapter must be replaced on the entire fleet.

Comments Invited

This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2005-22634; Directorate Identifier 2005-SW-12-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments. We will post all comments we receive, 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 AD. Using the search function of our docket Web site, you can find and read the comments to any of our dockets, including the name of the individual who sent the comment. 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.

Regulatory Findings

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

For the reasons discussed above, I certify that the 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 an economic evaluation of the estimated costs to comply with this AD. See the DMS to examine the economic evaluation.

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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

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Adoption of the Amendment

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Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (

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PART 39—AIRWORTHINESS DIRECTIVES

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

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]
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2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

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2005-20-38 Bell Helicopter Textron: Amendment 39-14335. Docket No. FAA-2005-22634; Directorate Identifier 2005-SW-12-AD.

Applicability

Model 212, 412, and 412EP helicopters modified with Aeronautical Accessories, Inc. (AAI), Supplemental Type Certificate (STC) SH2820SO; or with AAI Parts Manufacturer Approval (PMA) reservoir assembly, part number (P/N) 212-372-050; or with adapter, P/N 212-371-002, installed, certificated in any category.

Compliance

Required as indicated, unless accomplished previously.

To prevent rupture of an adapter, uncontrolled jetting of pressurized gas from the nitrogen bottle, and subsequent injury to occupants or damage to the helicopter, accomplish the following:

(a) Within the next 24 hours time-in-service (TIS) or before the next emergency floatation supply bottle nitrogen charging, whichever occurs first, do the following:

(1) Vent the nitrogen from the reservoir assembly by following the Accomplishment Instructions, Part II—Floatation System Discharging, of AAI Alert Service Bulletin ASB No. AA-05005, Revision A, dated June 27, 2005 (ASB).

(2) Remove the valve assembly and air line from the adapter, and inspect the counter bore depth (dimension D) as shown in Figure 1 of the ASB.

(i) If dimension D, as depicted in Figure 1 of the ASB, does not exceed .860 inch, recharge the floatation system by following the Accomplishment Instructions, Part III—Floatation System Charging, and referring to Figures 2 and 3 of the ASB.

(ii) If dimension D, as depicted in Figure 1 of the ASB, exceeds .860 inch, replace the reservoir assembly and the adapter with airworthy parts before further flight.

(b) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Rotorcraft Certification Office, FAA, for information about previously approved alternative methods of compliance.

(c) Discharging and recharging the floatation system and inspecting the counter bore depth dimension of the adapter shall be done in accordance with the specified portions of Aeronautical Accessories, Inc. Alert Service Bulletin No. AA-05005, Revision A, dated June 27, 2005. The Director of the Federal Register approved this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Aeronautical Accessories, Inc., P. O. Box 3689, Bristol, Tennessee 37625-3689. Copies may be inspected at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

(d) This amendment becomes effective on October 28, 2005.

Start Signature

Issued in Fort Worth, Texas, on September 30, 2005.

Scott A. Horn,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 05-20324 Filed 10-12-05; 8:45 am]

BILLING CODE 4910-13-P