E8-4489. Airworthiness Directives; MD Helicopters, Inc. Model 600N Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This document supersedes an existing airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model 600N helicopters. That AD currently requires interim initial and repetitive inspections of tailboom parts, installing six inspection holes in the aft fuselage skin panels, installing tailboom attachment bolt washers, modifying both access covers, and replacing broken attachment bolts. The current AD also provides for modifying the fuselage aft section as an optional terminating action. This amendment requires modifying the fuselage aft section within the next 24 months to strengthen the tailboom attachment fittings and upper longerons. The actions specified by this AD are intended to prevent failure of the tailboom attachment fittings, separation of the tailboom from the helicopter, and subsequent loss of control of the helicopter.

DATES:

Effective April 16, 2008.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of April 16, 2008.

ADDRESSES:

You may get the service information identified in this AD from MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, Arizona 85215-9734, telephone [phone], fax [phone], or on the Internet at http://www.mdhelicopters.com.

EXAMINING THE DOCKET:

You may examine the docket that contains this AD, any comments, and other information on the Internet at http://www.regulations.gov or at the Docket Operations office, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Jon Mowery, Aviation Safety Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 Paramount Blvd., Lakewood, California 90712, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

A proposal to amend 14 CFR part 39 by superseding AD 2006-08-12, Amendment 39-14569 (71 FR 24808, April 27, 2006), which superseded AD 2001-24-51, Amendment 39-12706 (67 FR 17934, April 12, 2002), for the specified MDHI model helicopters was published in the Federal Register on October 19, 2007 (72 FR 59227). The action proposed to require modifying the fuselage aft section within the next 24 months to strengthen the tailboom attachment fittings and upper longerons.

On January 12, 2004, MDHI issued Technical Bulletin (TB) TB600N-007 specifying procedures, tooling, replacement parts, and supplies needed for modifying the fuselage aft section and tailboom. TB600N-007R1, dated April 13, 2006, superseded TB600N-007 to correct some tooling, replacement parts, and supplies. TB600N-007R2, dated October 5, 2006, superseded TB600N-007R1 to correct tooling part numbers and re-sequence some assembly steps. These TBs specify that any aircraft complying with any of these revisions meets the intent of the other TBs.

In AD 2006-08-12, we incorporated by reference TB600N-007R1, dated April 13, 2006. Since issuing that AD, MDHI has issued TB600N-007R2, dated October 5, 2006 (TB), which updates previous issues by further specifying procedures for modifying the fuselage aft section to strengthen the tailboom attachment fittings and upper longerons. This latest revision continues to caution that a high level of sheet metal expertise and experience is required to perform this modification.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require adopting the rule as proposed.

The FAA estimates that this AD will affect 18 helicopters of U.S. registry, and the required actions will take about 322 work hours to modify each helicopter at an average labor rate of $80 per work hour. Required parts will cost about $14,960 per helicopter. The manufacturer states in its TB that those complying with the TB within 3 years of the issue date are eligible for special pricing and technical assistance. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $732,960, assuming no special pricing from the manufacturer.

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 AD docket 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
• Incorporation by reference
• 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 removing Amendment 39-14569 ( 71 FR 24808, April 27, 2006) and by adding a new airworthiness directive (AD), Amendment 39-15411, to read as follows:

2008-05-17 MD Helicopters, Inc.: Amendment 39-15411, Docket No. FAA-2007-29342, Directorate Identifier 2007-SW-08-AD. Supersedes AD 2006-08-12, Amendment 39-14569, Docket No. FAA-2006-24518, Directorate Identifier 2006-SW-10-AD.

Applicability: Model 600N helicopters, serial numbers with a prefix “RN” and 003 through 058, that have not been modified in the fuselage aft section to strengthen the tailboom attachments and longerons per MD Helicopters (MDHI) Technical Bulletin (TB) TB600N-007, dated January 12, 2004; TB600N-007R1, dated April 13, 2006, or TB600N-007R2, dated October 5, 2006, certificated in any category.

Compliance: Required within the next 24 months, unless accomplished previously.

To prevent failure of the tailboom attachment fittings, separation of the tailboom from the helicopter, and subsequent loss of control of the helicopter, do the following:

(a) Modify the fuselage aft section to strengthen the tailboom attach fittings and upper longerons by following paragraph 2, Accomplishment Instructions, of MDHI TB600N-007R2, dated October 5, 2006, except you are not required to contact the manufacturer. This modification to the fuselage aft section is terminating action for the requirements of this AD.

(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 Manager, Los Angeles Aircraft Certification Office, FAA, Attn: Jon Mowery, Aviation Safety Engineer, Airframe Branch, 3960 Paramount Blvd., Lakewood, California 90712, telephone [phone], fax [phone], for information about previously approved alternative methods of compliance.

(c) Modifying the fuselage aft section shall be done by following the specified portions of MD Helicopters Technical Bulletin (TB) TB600N-007R2, dated October 5, 2006. 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 MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, Arizona 85215-9734, telephone [phone], fax [phone], or on the Internet at http://www.mdhelicopters.com. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas or 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 April 16, 2008.

Issued in Fort Worth, Texas, on February 27, 2008.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.