E8-28109. Airworthiness Directives; Erickson Air-Crane Incorporated (Erickson) Model S-64F Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes adopting a new airworthiness directive (AD) for Erickson Model S-64F helicopters. The AD would require inspections for cracking or working rivets in each left and right splice fitting (transition fitting), the pylon bulkhead assembly—canted (bulkhead assembly), the pylon steel strap (strap), and the attaching rotary rudder boom and pylon structure. This proposal is prompted by several reports of cracking in the transition fittings, the bulkhead assembly, and pylon. The actions specified by the proposed AD are intended to detect cracking in the rotary rudder boom or pylon due to fatigue, and to prevent failure from static overload and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before January 26, 2009.

ADDRESSES:

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

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• 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: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, 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 Erickson Air-Crane Incorporated, ATTN: Chris Erickson/Compliance Officer, 3100 Willow Springs Rd., PO Box 3247, Central Point, OR 97502, telephone [phone], fax [phone], e-mail address [e-mail].

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-2008-1243, Directorate Identifier 2007-SW-03-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://www.regulations.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).

Examining the Docket: You may examine the docket that contains the proposed AD, any comments, and other information in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone [phone]) is located in Room W12-140 on the ground floor of the West Building at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

This document proposes adopting a new AD for Erickson Model S-64F helicopters with a transition fitting, part number (P/N) 6420-66341-101, -102, -103, or -104, a bulkhead assembly, P/N 6420-66340-041, -043, or -044, or a strap, P/N 6420-66301-119 or -127, installed. The AD would require inspections for cracking or working rivets in each transition fitting, the bulkhead assembly, the strap, and the attaching rotary rudder boom and pylon structure, and replacing or repairing any cracked or damaged part with an airworthy part. This proposal is prompted by several reports of cracking in the transition fittings, the bulkhead assembly, and the pylon. The cracks were discovered during inspections. The actions specified by the proposed AD are intended to detect cracking in the rotary rudder boom or pylon due to fatigue, and to prevent failure from static overload and subsequent loss of control of the helicopter.

We have reviewed Erickson Service Bulletin (SB) No. 64B20-6, Revision A, dated December 12, 2007, which describes procedures for inspecting the transition fittings, the bulkhead assembly, the strap, and the attaching rotary rudder boom and pylon structure for cracking or working rivets. We have also reviewed Erickson SB No. 64F General-3, Revision C, dated December 12, 2007, which summarizes a listing of a portion of the Model S-64F helicopter components, their part numbers, and the corresponding service bulletins to use when performing the structural inspections.

The unsafe condition associated with the fatigue cracking and working rivets is likely to exist or develop on other helicopters of the same type design. Therefore, the proposed AD would require, within 20 hours time-in-service (TIS), and thereafter at intervals not to exceed 20 hours TIS:

• Visually inspecting each transition fitting for a crack or working rivets on the inboard face of the rotary rudder boom and pylon;
• Visually inspecting the outboard face of each rotary rudder boom and pylon skin panel (skin panel) that attaches to the transition fittings for a crack or working rivets in the transition fitting attachment areas;
• Visually inspecting the forward and aft sides of the bulkhead assembly for a crack;
• Visually inspecting the upper 12 inches of the strap for a crack or for working rivets; and
• Visually inspecting the pylon on each side of the upper 12 inches of the strap, and also 6 inches above the strap, for a crack or working rivets.

For any pylon with a strap installed, the proposed AD would require, within 155 hours TIS, and thereafter at intervals not to exceed 155 hours TIS, removing the inspection panels, P/N 6420-66304-109 and 6420-66303-125, on the forward and aft sides of the pylon, and visually inspecting the left-hand cap angle (longeron), P/N 6420-66304-136, and the interior area of the pylon that is adjacent to the upper 12 inches of the strap, as well as 6 inches above the end of the strap, for a crack or working rivets. At each 8,300 hours TIS transition fitting replacement, the proposed AD would require:

• With the transition fitting removed, visually inspecting both sides of each skin panel for a crack in the areas to which the transition fitting attaches; and
• Performing a fluorescent penetrant inspection of the skin panels for a crack in the area around the fastener holes attaching the transition fittings to the rotary rudder boom and pylon.

The proposed AD would also require, before further flight:

• Inspecting any part and the surrounding area using a 10-power or higher magnifying glass if you cannot visually determine that a crack does not exist in that part;
• Performing a fluorescent penetrant inspection of any part, other than a strap, if you cannot determine that a crack does not exist in the part after inspecting it with a 10-power or higher magnifying glass;
• Performing a magnetic particle inspection of any strap if you cannot determine that a crack does not exist in the strap after inspecting it with a 10-power or higher magnifying glass;
• If a crack is found, replacing any cracked part with an airworthy part or repairing that part if it is within the maximum repair damage limits; and
• If any loose or working rivets are found, removing the rivets, visually inspecting the fastener holes and surrounding area for a crack or any other damage, and replacing any cracked part with an airworthy part or replacing any damaged part with an airworthy part if the damage exceeds the maximum repair damage limits or repairing any damaged part, if the part is within the maximum repair damage limits.

Finally, replacing any loose or working rivet would be required. The actions would be required to be accomplished by following specified portions of the service bulletin described previously.

We estimate that this proposed AD would affect 7 helicopters of U.S. registry, and the proposed actions would take approximately:

• 0.75 work hour for the visual inspection of the transition fittings, skin panels, the bulkhead assembly, strap, and pylon exterior in the strap area with 30 inspections per year;
• 0.50 work hour for the visual inspection of the pylon interior in the strap area with 4 inspections per year;
• 0.75 work hour for the visual and fluorescent penetrant inspections of the skin panels at the transition fitting with 1 inspection per year; and
• 40 work hours per helicopter to repair a pylon structural assembly.

The average labor rate is $80 per work hour. Required parts would cost approximately $50,000 per helicopter to repair a pylon structural assembly, if needed. The estimated cost of labor for the inspections of 7 helicopters would be $14,140. The estimated cost to repair the pylon structural assembly on a helicopter, including the cost of the replacement parts and labor, would be $53,200. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $67,340 per year for the fleet, assuming a pylon structural assembly on one helicopter would need to be repaired.

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 an economic evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

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
• Incorporation by reference
• 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:

Erickson Air-Crane Incorporated: Docket No. FAA-2008-1243; Directorate Identifier 2007-SW-03-AD.

Applicability: Model S-64F helicopters, with any of the parts listed in Table 1 of this AD installed, certificated in any category.

Table 1

Installed part	Part number (P/N)
Left or right splice fitting (transition fitting)	6420-66341-101, -102, -103, or -104
Pylon bulkhead assembly—canted (bulkhead assembly)	6420-66340-041, -043, or -044
Pylon steel strap (strap)	6420-66301-119 or -127

Compliance: Required as indicated.

To detect cracking in the rotary rudder boom or pylon due to fatigue, and to prevent failure from static overload and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 20 hours time-in-service (TIS), unless accomplished previously, and thereafter at intervals not to exceed 20 hours TIS:

(1) Visually inspect each transition fitting, P/N 6420-66341-101, -102, -103, or -104, for a crack or working rivets on the inboard face of the rotary rudder boom and pylon, paying particular attention to the fastener attachment holes, as depicted in Figure 1, Detail A, of the Accomplishment Instructions in Erickson Air-Crane Incorporated Service Bulletin No. 64B20-6, Revision A, dated December 12, 2007 (SB).

(2) Visually inspect the outboard face of each rotary rudder boom and pylon skin panel (skin panel) that attaches to the transition fittings for a crack or working rivets in the transition fitting attachment areas, paying particular attention to the fastener attachment holes, as shown in Figure 1, Detail B, of the Accomplishment Instructions in the SB.

(3) Visually inspect the forward and aft sides of each bulkhead assembly, P/N 6420-66340-041, -043, or -044, for a crack. Pay particular attention to the circled areas shown in Figure 2 of the Accomplishment Instructions in the SB.

(4) Visually inspect the upper 12 inches of each strap, P/N 6420-66301-119 or -127, for a crack or for working rivets as shown in Figure 3 of the Accomplishment Instructions in the SB.

(5) Visually inspect the pylon for a crack or working rivets on each side of the upper 12 inches of the strap, and also 6 inches above the end of the strap as shown in Figure 3 of the Accomplishment Instructions in the SB.

(b) For any pylon with a strap installed, within 155 hours TIS, unless previously accomplished, and thereafter at intervals not to exceed 155 hours TIS, remove the inspection access covers, P/N 6420-66304-109 and P/N 6420-66303-125, on the forward and aft sides of the pylon and visually inspect the left-hand cap angle (longeron), P/N 6420-66304-136, and the interior area of the pylon adjacent to the upper 12 inches of the strap, as well as 6 inches above the end of the strap, for a crack or working rivets, as shown in Figure 3 of the Accomplishment Instructions in the SB.

(c) At each transition fitting replacement, which is required at intervals not to exceed 8,300 hours TIS:

(1) With each transition fitting removed, visually inspect both sides of each skin panel for a crack in the areas to which the transition fitting attaches, paying particular attention to the fastener attachment holes, as depicted in Details A and B, Figure 1, of the Accomplishment Instructions in the SB.

(2) Perform a fluorescent penetrant inspection of each skin panel for a crack in the areas around the fastener holes where the transition fittings attach to the rotary rudder boom and pylon.

(d) Before further flight, accomplish the following:

(1) If you cannot visually determine that a crack does not exist in a part, inspect the part and the surrounding area using a 10-power or higher magnifying glass.

(2) If you cannot determine that a crack does not exist in a part other than a strap after inspecting it with a 10-power or higher magnifying glass, perform a fluorescent penetrant inspection of the part.

(3) If you cannot determine that a crack does not exist in a strap after inspecting it with a 10-power or higher magnifying glass, perform a magnetic particle inspection of the strap.

(e) If a crack is found, before further flight, replace any cracked part with an airworthy part, or repair the cracked part if the damage is within the maximum repair damage limits.

Note:

The maximum repair damage limitations are stated in the applicable Component and Repair Overhaul Manual.

(f) If any loose or working rivets are found, before further flight, remove the rivets and visually inspect the fastener holes and surrounding area for a crack or any other damage. Replace any part that is cracked with an airworthy part; replace any damaged part with damage exceeding the maximum repair damage limits with an airworthy part or repair any damaged part that is within the maximum repair damage limits. Also, replace any loose or working rivets.

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

(h) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the inspection requirements of this AD can be accomplished. No special flight permits will be issued to accomplish replacements or repairs, or if a crack is suspected.

Issued in Fort Worth, Texas, on November 14, 2008.

Scott A. Horn,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.