E7-4525. Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205A, 205A-1, 205B, 212, 412, 412CF, and 412EP Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes superseding an existing airworthiness directive (AD) for the specified Bell Helicopter Textron, Inc. (Bell) helicopters. That AD currently requires inspecting each affected tail rotor blade (blade) forward tip weight retention block (tip block) and the aft tip closure (tip closure) for adhesive bond voids, and removing any blade with an excessive void from service. That AD also requires modifying certain blades by installing shear pins and tip closure rivets. This action would contain the same requirements but would expand the applicability to include other part and serial-numbered blades. This AD would also clarify the requirement to re-identify the modified blade by adding “FM” after the part number and would require dynamically balancing the tail rotor. The existing AD was prompted by five occurrences of missing tip blocks or tip closures resulting in minor to substantial damage. This proposal was prompted by the determination that the AD should apply to other affected part and serial-numbered blades. The actions specified by this proposed AD are intended to prevent loss of a tip block or tip closure, loss of a blade, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before May 14, 2007.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed 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: [phone]; 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 proposed AD from Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101, telephone [phone], fax [phone].

You may examine the comments to this proposed AD in the AD docket on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT:

Michael Kohner, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort Worth, Texas 76193-0170, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any written data, views, or arguments regarding this proposed AD. Send your comments to the address listed under the caption ADDRESSES. Include the docket number “FAA-2007-27496, Directorate Identifier 2005-SW-37-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed 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 proposed rulemaking. 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 or signed 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.

Examining the Docket

You may examine the docket that contains the proposed AD, any comments, and other information in person at the Docket Management System (DMS) Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) is located at the plaza level of the Department of Transportation NASSIF Building in Room PL-401 at 400 Seventh Street, SW., Washington, DC. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

On April 22, 2002, we issued AD 2002-09-04, Amendment 39-12737 (67 FR 22349, May 3, 2002), to require inspecting the tip block and the tip closure for adhesive bonding voids, and removing any blade with an excessive void from service. The AD also required modifying certain blades by installing shear pins and tip closure rivets in the tip area of the affected blades. That action was prompted by five occurrences of missing tip blocks or tip closures resulting in minor to substantial damage. The requirements of that AD are intended to prevent loss of a tip block or tip closure, loss of a blade, and subsequent loss of control of the helicopter.

Since issuing that AD, Bell has issued further revisions to Alert Service Bulletin (ASB) Nos. 205-00-80, 205B-00-34, 212-00-111, 412-00-106, and 412CF-00-13, Revision A, dated December 20, 2000. The revisions add blades with a serial number (S/N) A or AFS-11530 to 13594, 13603 to 13618, and changed the “effectivity” of the blades. The latest revision, Revision D, dated March 18, 2005, provides an alternate fastener for the blade tip closure rivets installation. The revised ASB also states that blades with S/N A or AFS-11926, 13351, 13367, 13393, 13400, 13402, 13515, 13540, 13568, 13595 to 13602, and 13619 and subsequent will have the intent of the ASBs accomplished before delivery.

The previously described unsafe condition is likely to exist or develop on other helicopters of these same type designs. Therefore, the proposed AD would supersede AD 2002-09-04 to expand the applicability for the blade part and serial number. The proposed AD would also clarify the requirement to re-identify the modified blade by adding “FM” after the part number and would also require dynamically balancing the tail rotor. Because blades with a S/N with a prefix of “A” or “AFS” and a number 11926, 13351, 13367, 13393, 13400, 13402, 13515, 13540, 13568, 13595 to 13602, and 13619 and subsequent will have the modification required by this AD accomplished before delivery, we would exclude them from the applicability of this AD.

We estimate that this proposed AD would affect 281 helicopters of U.S. registry. The proposed actions would take about 3 work hours per helicopter to inspect certain blades, install the shear pins and tip closure rivets, re-identify the modified blades, and dynamically balance the blade assembly at an average labor rate of $80 per work hour. Required supplies would cost about $35 per helicopter. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $77,275.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. Additionally, 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 draft economic evaluation of the estimated costs to comply with this proposed AD. See the DMS to examine the draft 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.

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 removing Amendment 39-12737 (67 FR 22349, May 3, 2002), and by adding a new airworthiness directive (AD), to read as follows:

Bell Helicopter Textron, Inc.: Docket No. FAA-2007-27496; Directorate Identifier 2005-SW-37-AD. Supersedes AD 2002-09-04, Amendment 39-12737, Docket No. 2001-SW-37-AD.

Applicability

Model 205A, 205A-1, 205B, 212, 412, 412CF, and 412EP helicopters with a tail rotor blade (blade), part number 212-010-750-009 through -129, all serial numbers except serial numbers with a prefix of “A” or “AFS” and the number 11926, 13351, 13367, 13393, 13400, 13402, 13515, 13540, 13568, 13595 through 13602, 13619, and subsequent assigned numbers, installed, certificated in any category.

Compliance

Within 100 hours time-in-service, unless accomplished previously.

To prevent loss of the forward tip weight retention block (tip block) or aft tip closure (tip closure), loss of the blade, and subsequent loss of control of the helicopter, accomplish the following:

(a) Inspect the tip block and tip closure for voids. Remove from service any blade with a void in excess of that allowed by the Component Repair and Overhaul Manual limitations.

(b) Inspect the tip block attachment countersink screws in four locations to determine if the head of each countersunk screw is flush with the surface of the abrasion strip. The locations of these four screws are depicted on Figure 1 of Bell Helicopter Textron, Inc. Alert Service Bulletins 205-00-80, 205B-00-34, 212-00-111, 412-00-106, and 412CF-00-13, all Revision D, all dated March 18, 2005 (ASB). If any of these screws are set below the surface of the abrasion strip or are covered with filler material, install shear pins by following the Accomplishment Instructions, Part A, Shear Pin Installation paragraphs, of the ASB appropriate for your model helicopter.

(c) Install the aft tip closure rivets, re-identify the modified blade by adding an “FM,” and dynamically balance the tail rotor hub assembly by following the Accomplishment Instructions, Part B, Aft Tip Closure Rivet Installation paragraphs, of the ASB appropriate for your model helicopter.

(d) 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 Manager, Rotorcraft Certification Office, Rotorcraft Directorate, FAA, ATTN: Michael Kohner, Aviation Safety Engineer, Fort Worth, Texas 76193-0170, telephone [phone], fax [phone], for information about previously approved alternative methods of compliance.

Issued in Fort Worth, Texas, on February 28, 2007.

S. Frances Cox,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.