E7-13607. Airworthiness Directives; Bell Helicopter Textron Canada Limited Model 206A and 206B Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (BHTC) Model 206A and 206B helicopters, serial numbers (S/N) 0004 through 3906, with two-piece vertical stabilizer (fin) supports (fin supports) installed. This proposal would require inserting a revision into the applicable maintenance manual, verifying the torque on the fin support attachment hardware, inspecting the fin support bracket and vertical fin for paint or gaps, and inspecting the fin support bracket for cracking, and if a crack is found, replacing the two-piece vertical fin support with a one-piece casting support. This proposal is prompted by an accident in which the fin supports failed. The actions specified by this proposed AD are intended to detect improper torque of the fin support attachment hardware, gaps between the fin support bracket and the doubler, painted mating surfaces of the fin supports, vertical fin, and vertical fin inserts (fin inserts), and cracking in the fin supports, to prevent the vertical fin from rotating into the tail rotor, separation of the tail rotor, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before September 11, 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: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590;
• Hand Delivery: Deliver to the “Mail” address between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays; or
• Fax: [phone].

You may get the service information identified in this proposed AD from Bell Helicopter Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4, telephone [phone] or [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:

Sharon Miles, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Policy Group, Fort Worth, Texas 76193-0111, 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-2007-28690, Directorate Identifier 2006-SW-21-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 in Room W12-140 on the ground floor of the West Building, 1200 New Jersey Avenue SE., Washington, DC. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

This document proposes adopting a new AD for BHTC Model 206A and 206B helicopters, S/N 0004 through 3906, with fin supports, part numbers (P/N) 206-031-417-003 or -007, or 206-031-418-001 or -005, installed. This proposal would require inserting a revision into the Scheduled Inspection section, chapter 5, of the applicable maintenance manual, implementing a recurring inspection at intervals not to exceed 100 hours time-in-service (TIS) or at each annual inspection, whichever occurs first, of the torque on the fin supports' attachment hardware, and inspecting the fin support for damage. Inspecting for paint on the mating surfaces of the fin support bracket and vertical fin; inspecting the vertical fin attaching hardware for proper torque and the amount of gap between the vertical fin support bracket and the vertical fin doubler; inspecting the fin support bracket for cracking using a 10× or higher power magnifying glass; and if either the torque or gap is out of limits or paint is present, fluorescent penetrant inspecting the vertical fin support for cracking would also be required. If a crack is found, replacing the vertical fin support with a one-piece casting support, P/N 206-033-426-003, would be required. This proposal is prompted by an accident in which the fin supports failed, allowing the lower part of the fin to contact the tail rotor blades, which resulted in subsequent separation of the gearbox and tail rotor from the helicopter. The actions specified by this proposed AD are intended to detect improper torque of the fin support attachment hardware, gaps between the fin support bracket and the doubler, painted mating surfaces of the fin supports, vertical fin, and fin inserts, and cracking in the fin supports, to prevent the vertical fin from rotating into the tail rotor, separation of the tail rotor, and subsequent loss of control of the helicopter.

Transport Canada, the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on BHTC Model 206A and 206B helicopters, S/N 004 through 3906, with fin supports, P/N 206-031-417-003 or -007, or 206-031-418-001 or -005, installed. Transport Canada advises that a one-time inspection of the vertical fin mating surfaces is required to ensure an appropriate surface finish. In addition, they advise that a recurring torque check of the vertical fin attaching hardware is required to maintain the structural integrity of the joint. They also advise that the initial inspection be performed at the next scheduled 100 hour TIS or annual inspection, but within three (3) months in accordance with BHTC Alert Service Bulletin No. 206-06-107, dated April 26, 2006, or later revisions approved by Transport Canada.

BHTC has issued Alert Service Bulletin No. 206-06-107, Revision A, dated June 15, 2006, which specifies a series of inspections of the two-piece fin supports, and also introduces revisions to Chapters 5 and 53 of the BHT-206A/B Series Maintenance Manual. The revision to Chapter 5 introduces a recurring vertical fin attaching hardware torque check and inspecting the fin supports for damage, which are to be accomplished at the next scheduled 100 hour TIS or annual inspection. The revision to Chapter 53 updates the procedures for removal, installation, and inspection of the vertical fin. Transport Canada classified this alert service bulletin as mandatory and issued AD No. CF-2006-12, dated June 5, 2006, to ensure the continued airworthiness of these helicopters in Canada.

These helicopter models are manufactured in Canada and are type certificated for operation in the United States under the provisions of 14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the applicable bilateral agreement, Transport Canada has kept us informed of the situation described above. We have examined the findings of the Transport Canada, reviewed all available information, and determined that AD action is necessary for products of these type designs that are certificated for operation in the United States.

This previously described unsafe condition is likely to exist or develop on other helicopters of the same type designs registered in the United States. Therefore, the proposed AD would require, at the next scheduled 100 hour TIS inspection, but no later than 90 days from the effective date of this AD, unless accomplished previously, and thereafter at intervals not to exceed 100 hours TIS or at each annual inspection, whichever occurs first, verifying the torque on the fin support attachment hardware. Inspecting the fin support bracket and vertical fin for paint or gaps, inspecting the fin support bracket for cracking using a 10x or higher power magnifying glass, and if needed, fluorescent penetrant inspecting for cracking would also be required, as well as replacing any two-piece fin support on which a crack is found with a one-piece casting support. Inserting a revision into the applicable maintenance manual would also be required. The actions would be required to be accomplished by following the specified portions of the alert service bulletin described previously.

We estimate that this proposed AD would affect 1,466 helicopters of U.S. registry and the proposed inspections would take approximately 4 work hours per helicopter at an average labor rate of $80 per work hour. If needed, replacing a fin support would take approximately 30 work hours. Required parts would cost approximately $3,260 for each fin support. Based on these figures, we estimate the total cost impact of the proposed AD on U.S. operators to be $3,300,820 for the fleet during the first year, assuming 7 inspections per helicopter are conducted, and assuming that replacing the fin support is required on 3 helicopters.

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 adding a new airworthiness directive to read as follows:

Bell Helicopter Textron Canada Limited: Docket No. FAA-2007-28690; Directorate Identifier 2006-SW-21-AD.

Applicability: Model 206A and 206B helicopters, serial numbers 0004 through 3906, with two-piece vertical stabilizer (fin) supports (fin supports), part number (P/N) 206-031-417-003 or -007, or P/N 206-031-418-001 or -005, installed, certificated in any category.

Compliance: Required at the next scheduled 100 hour time-in-service (TIS) inspection or annual inspection, but no later than 90 days after the effective date of this AD, unless accomplished previously, and thereafter at intervals not to exceed 100 hours TIS or at each annual inspection, whichever occurs first.

To detect improper torque of the fin support attachment hardware, gaps between the fin support bracket and the doubler, painted mating surfaces of the fin supports, vertical fin, and vertical fin inserts (fin inserts), and cracks in the fin supports, to prevent the vertical fin from rotating into the tail rotor, separation of the tail rotor, and subsequent loss of control of the helicopter, accomplish the following:

(a) Insert Revision 4 of BHT-206A/B-SERIES-MM into the appropriate section of the maintenance manual.

(b) Determine the type and part number of the installed vertical fin by referring to the listing in step 2., Table 1, of the Accomplishment Instructions of Bell Helicopter Textron Alert Service Bulletin No. 206-06-107, Revision A, dated June 15, 2006 (ASB).

(c) For Type 1 and Type 3 vertical fins, inspect the vertical fin and fin support bracket for paint, and the vertical fin attaching hardware for proper torque, in accordance with steps 5. and 6. of the Accomplishment Instructions of the ASB.

(d) For Type 2 vertical fins, inspect the vertical fin and fin support bracket for paint, the vertical fin attaching hardware for proper torque, and the amount of gap between the vertical fin support bracket and the vertical fin doubler in accordance with steps 5., 6., and 7. of the Accomplishment Instructions of the ASB.

(e) If the inspections required by paragraphs (c) and (d) of this AD indicate that the torque and gap are within limits, and there is no paint present, visually inspect the vertical fin support bracket in the area of the vertical fin attaching hardware for a crack using a 10x or higher power magnifying glass.

(1) If no crack is found, re-torque the vertical fin attaching hardware to between 75 and 95 in. lbs. (8.47 to 10.75 Nm).

(2) If a crack is found, replace the two-piece vertical fin support bracket with a one-piece vertical fin casting support, P/N 206-033-426-003.

(f) Based on your finding in paragraphs (c) and (d) of this AD, if either the torque or gap is out of limits, or paint is present:

(1) Remove the vertical fin.

(2) Remove all the primer and paint coatings in the areas indicated in Figure I of the ASB.

(3) Fluorescent penetrant inspect (FPI) the vertical fin support.

(4) If a crack is found, replace the two-piece vertical fin support with a one-piece vertical fin casting support, P/N 206-033-426-003.

(5) If no crack is found, apply two coats of Polyamide Epoxy Primer on bare metal surfaces.

(g) For Type 2 vertical fins only:

(1) If incorrect washers (spacers) or no washers are installed, visually inspect the 4 vertical fin potted inserts as depicted in the vertical fin detail in Figure I of the ASB for any damage using a 10x or higher power magnifying glass.

(2) If any of the 4 vertical fin potted inserts is damaged with no other damage to the surrounding areas, remove and replace the damaged potted insert with an airworthy potted insert.

(3) After assuring that all 4 installed vertical fin potted inserts are undamaged, install the correct washers in accordance with step 9.d. of the Accomplishment Instructions of the ASB.

(h) This AD revises the helicopter maintenance manual by adding an inspection of the torque on the vertical fin attaching hardware, and inspections of the vertical fin and vertical fin support, to the 100-hour TIS and annual scheduled inspections.

(i) 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, Regulations and Policy Group, FAA, ATTN: Sharon Miles, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Policy Group, Fort Worth, Texas 76193-0111, telephone [phone], fax [phone], for information about previously approved alternative methods of compliance.

Note:

The subject of this AD is addressed in Transport Canada (Canada) AD No. CF-2006-12, dated June 5, 2006.

Issued in Fort Worth, Texas, on July 3, 2007.

David A. Downey,

Manager, Rotorcraft Directorate, Aircraft Certification Service.