07-3711. Airworthiness Directives; Enstrom Helicopter Corporation Model F-28, F-28A, F-28C, F-28C-2, F-28C-2R, F-28F, F-28F-R, 280, 280C, 280F, 280FX, TH-28, 480, and 480B Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) for Enstrom Helicopter Corporation (Enstrom) Model F-28, F-28A, F-28C, F-28C-2, F-28C-2R, F-28F, F-28F-R, 280, 280C, 280F, 280FX, TH-28, 480, and 480B helicopters. This action requires a visual check to determine if a certain serial-numbered main rotor blade retention pin (retention pin) is installed, and removing and replacing any affected retention pin with an airworthy retention pin. This amendment is prompted by a report from the manufacturer that some retention pins were not manufactured in accordance with specifications cited on the engineering drawing. The actions specified in this AD are intended to prevent failure of a retention pin, separation of a main rotor blade from the helicopter, and subsequent loss of control of the helicopter.

DATES:

Effective August 15, 2007.

Comments for inclusion in the Rules Docket must be received on or before October 1, 2007.

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: 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 AD from Enstrom Helicopter Corporation, 2209 22nd Street, P.O. Box 490, Menominee, Michigan 49858-0490.

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 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 the DMS receives them.

FOR FURTHER INFORMATION CONTACT:

Gregory J. Michalik, Senior Aerospace Engineer, FAA, Small Airplane Directorate, Chicago Aircraft Certification Office, 2300 E. Devon Ave., Room 107, Des Plaines, Illinois 60018, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

This amendment adopts a new AD for Enstrom Model F-28, F-28A, F-28C, F-28C-2, F-28C-2R, F-28F, F-28F-R, 280, 280C, 280F, 280FX, TH-28, 480, and 480B helicopters with a retention pin, part number (P/N) 28-14007-3, installed, with a serial number (S/N) that is listed in the following table:

04098-01 through 04098-56.

05018-01 through 05018-36.

05143-01 through 05143-56.

05341-1 through 05341-8.

05341-10 through 05341-17.

05341-19.

05341-21 through 05341-33.

05341-35 through 05341-42.

05341-44 through 05341-59.

05341-61.

05341-62.

05341-64 through 05341-71.

06214-3 through 06214-14.

06214-16 through 06214-23.

06214-25 through 06214-29.

06214-31.

06214-33 through 06214-35.

06214-37 through 06214-57.

06214-59 through 06214-68.

This action requires, before further flight, visually checking each retention pin to determine if the S/N, which is marked on the head of the retention pin, is listed in the Applicability section of this AD. If there is no serial number marked on the head of the retention pin (i.e., the retention pin head is blank), the retention pin does not need to be replaced and this visual check constitutes a terminating action for the requirements of this AD for that retention pin. If an affected retention pin is installed, determining the retention pin's number of hours time-in-service (TIS) and removing and replacing it with an airworthy retention pin that has a S/N that is not listed in the Applicability section of this AD is required:

• Within the next 5 hours TIS or within 30 days, whichever occurs first, if the retention pin has 545 or more hours TIS, or
• On or before reaching 550 hours TIS or within 30 days, whichever occurs first, if the retention pin has less than 545 hours TIS.

This amendment is prompted by a report from the manufacturer that some retention pins were manufactured from steel that did not meet the specifications cited on the engineering drawing. The actions specified in this AD are intended to prevent failure of a retention pin, separation of a main rotor blade from the helicopter, and subsequent loss of control of the helicopter.

We have reviewed Enstrom Helicopter Corporation Service Directive Bulletin (SDB) No. 0102 and Enstrom Helicopter Corporation SDB No. T-029, both dated March 20, 2007, which specify visual and magnetic particle inspections for cracks in certain serial-numbered retention pins, and repairing or replacing retention pins in accordance with certain inspection criteria. This AD does not require inspections for cracks but requires that each affected retention pin be replaced.

This unsafe condition is likely to exist or develop on other helicopters of the same type design. Therefore, this AD is being issued to prevent failure of a retention pin, separation of a main rotor blade from the helicopter, and subsequent loss of control of the helicopter. This AD requires removing and replacing certain serial-numbered retention pins. The visual check required by this AD may be performed by an owner/operator (pilot), but must be entered into the aircraft records showing compliance with paragraph (a) of this AD in accordance with 14 CFR 43.11 and 91.417(a)(2)(v). This AD allows a pilot to perform this check because it involves only a visual check of the head of each retention pin to determine the S/N.

The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability and structural integrity of the helicopter. Therefore, removing and replacing each affected retention pin is required within 5 hours TIS or within 30 days, depending on the retention pin's hours TIS, which constitutes a very short time period, and 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.

We estimate that this AD will affect 39 helicopters, and

• Determining the S/N of all retention pins (3 on each helicopter) will take approximately 0.5 work hour;
• Determining the hours TIS of three affected retention pins will take approximately 1 work hour; and
• Removing and replacing three retention pins will take approximately 3 work hours at an average labor rate of $80 per work hour. Required parts will cost approximately $680 per helicopter. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $1,040 per helicopter or $40,560 if all retention pins get 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-2007-28813; Directorate Identifier 2007-SW-09-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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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:

2007-16-01 Enstrom Helicopter Corporation: Amendment 39-15140. Docket No. FAA-2007-28813; Directorate Identifier 2007-SW-09-AD.

Applicability: Model F-28, F-28A, F-28C, F-28C-2, F-28C-2R, F-28F, F-28F-R, 280, 280C, 280F, 280FX, TH-28, 480, and 480B helicopters, with a main rotor blade retention pin (retention pin) having a serial number (S/N) that is listed in the following table, installed, certificated in any category:

04098-01 through 04098-56.

05018-01 through 05018-36.

05143-01 through 05143-56.

05341-1 through 05341-8.

05341-10 through 05341-17.

05341-19.

05341-21 through 05341-33.

05341-35 through 05341-42.

05341-44 through 05341-59.

05341-61.

05341-62.

05341-64 through 05341-71.

06214-3 through 06214-14.

06214-16 through 06214-23.

06214-25 through 06214-29.

06214-31.

06214-33 through 06214-35.

06214-37 through 06214-57.

06214-59 through 06214-68.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of a retention pin, separation of a main rotor blade from the helicopter, and subsequent loss of control of the helicopter, accomplish the following:

(a) Before further flight, check the S/N that is marked on the head of each retention pin to see if it is a S/N that is listed in the Applicability section of this AD. See Figure 1 for the location of the S/N. If there is no serial number marked on the head of the retention pin (i.e., the retention pin head is blank), the retention pin does not need to be replaced and this determination constitutes a terminating action for the requirements of this AD for that retention pin.

(b) The visual check required by paragraph (a) of this AD may be performed by an owner/operator (pilot) holding at least a private pilot certificate, and must be entered into the aircraft records showing compliance with paragraph (a) of this AD in accordance with 14 CFR sections 43.11 and 91.417(a)(2)(v).

(c) Determine the number of hours TIS for any affected retention pin and replace the retention pin with an airworthy retention pin as follows:

(1) For a retention pin with 545 or more hours TIS, remove the retention pin and replace it with an airworthy retention pin with a S/N that is not listed in the Applicability section of this AD within the next 5 hours TIS or within 30 days, whichever occurs first.

(2) For a retention pin with less than 545 hours TIS, remove the retention pin and replace it with an airworthy retention pin with a S/N that is not listed in the Applicability section of this AD on or before reaching 550 hours TIS or within 30 days, whichever occurs first.

Note:

Enstrom Service Directive Bulletin No. T-029 and Enstrom Service Directive Bulletin 0102, both dated March 20, 2007, pertain to the subject of this AD.

(d) Removing any affected retention pin and replacing it with an airworthy retention pin that is not included in the Applicability section of this AD is considered a terminating action for the requirements of this AD for that retention pin.

(e) 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, Chicago Aircraft Certification Office, FAA, ATTN: Gregory J. Michalik, Senior Aerospace Engineer, 2300 E. Devon Ave., Room 107, Des Plaines, Illinois, 60018, telephone [phone], fax [phone], for information about previously approved alternative methods of compliance.

(f) This amendment becomes effective on August 15, 2007.

Issued in Fort Worth, Texas, on July 24, 2007.

David A. Downey,

Manager, Rotorcraft Directorate, Aircraft Certification Service.