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Proposed Rule

Airworthiness Directives; MD Helicopters, Inc. Model 369A, OH-6A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, and 369HS Helicopters

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes adopting a new airworthiness directive Start Printed Page 13516(AD) for MD Helicopters, Inc. (MDHI) Model 369A, OH-6A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, and 369HS helicopters. The proposed AD would require repetitive tap inspections of each tail rotor (T/R) blade abrasion strip. This proposal is prompted by an incident in which an abrasion strip separated from a T/R blade. The actions specified by the proposed AD are intended to prevent disbonding and subsequent separation of an abrasion strip from a T/R blade, which could result in vibration, loss of the T/R, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before May 12, 2008.

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: 202-493-2251.
  • 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 Helicopter Technology Company, LLC (HTC) service information identified in this proposed AD from, HTC, 12902 South Broadway, Los Angeles, California, 90061, telephone (310) 523-2750, fax (310) 523-2745, or on the Internet at http://www.helicoptertech.com. The service information referenced in Note 2 of this proposed AD may be obtained from MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, Arizona 85215-9734, telephone (800) 388-3378, fax (480) 346-6813, or on the Internet at http://www.mdhelicopters.com.

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

Start Further Info

FOR FURTHER INFORMATION CONTACT:

John Cecil, Aviation Safety Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 Paramount Blvd., Lakewood, California 90712-4137, telephone (562) 627-5228, fax (562) 627-5210.

End Further Info End Preamble Start Supplemental Information

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-2008-0287, Directorate Identifier 2006-SW-15-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 the 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).

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 (800) 647-5527) 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 MDHI Model 369A, OH-6A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, and 369HS helicopters, with any of the following T/R blades installed:

  • HTC part number (P/N) 500P3100-101 and -103, or MDHI P/N 369D21640-501, -503, and -505.
  • HTC P/N 500P3100-301 and -303, or MDHI P/N 369D21641-501, -503, and -505.
  • HTC P/N 500P3300-501 and -503, or MDHI P/N 369D21643-501, -503, and -505.
  • HTC P/N 500P3500-701 and -703, or MDHI P/N 369D21642-501, -503, and -505.

Note:

An “M” or an “I” painted on the root of the T/R blade indicates compliance to an Alternate Method of Compliance (AMOC) to AD 2003-08-51, (Docket No. 2003-SW-17-AD, Amendment 39-13215 (68 FR 39449, July 2, 2008), corrected at 68 FR 47447, August 11, 2003, issued by the FAA, Los Angeles Aircraft Certification Office (LAACO) on June 13, 2003 to HTC. The AMOC addressed shot peening of the pitch horn of the T/R assembly.

The proposed AD would require, within 25 hours time-in-service (TIS), and thereafter at intervals not to exceed 25 hours TIS, tap inspections of the upper and lower surfaces of each T/R blade abrasion strip using a coin (United States 25-cent piece or equivalent), or a small brass, mild steel, or aluminum hammer, to detect bonding voids that exceed 0.2 square inch in size with a minimum of 1.0 inch between voids, at least 75 percent of the bonded area of the abrasion strip being free from voids, and no voids at the edge of the abrasion strip. Modifying each T/R blade in accordance with FAA-approved data by installing a titanium rivet in the tip of the outboard end of each T/R blade and painting a “T” in the root-end of the T/R blade would be considered terminating action for the AD. This proposal is prompted by an incident in which an abrasion strip separated from a T/R blade during flight. The actions specified by the proposed AD are intended to prevent disbonding and subsequent separation of an abrasion strip from a T/R blade, which could result in vibration, loss of the T/R, and subsequent loss of control of the helicopter.

We have reviewed the following service information:

  • HTC Mandatory SB Notice No. 3100-4R4, dated May 10, 2006, which describes procedures for periodic inspection of the abrasion strip-to-skin bond integrity on each T/R blade, and modifying each T/R blade by installing a titanium rivet, P/N 500P3124-13, in the tip of the T/R blade, and painting a “T” in the root-end of the T/R blade in accordance with applicable engineering drawings or standard repair instructions; and
  • MD Helicopters Service Bulletin SB369D-203R1, SB369E-097R1, SB369F-082R1, and SB369H-246R1, dated January 23, 2006, which describes procedures for periodic inspections of the T/R abrasion strip-to-skin bond integrity and modification of the T/R blade by HTC to install a titanium rivet in the tip of the T/R blade.

This unsafe condition is likely to exist or develop on other helicopters of the same type designs. Therefore, the proposed AD would require, within 25 hours TIS, unless accomplished previously, and thereafter at intervals Start Printed Page 13517not to exceed 25 hours TIS, tap inspections of the upper and lower surfaces of each T/R blade abrasion strip using a coin (United States 25 cent piece or equivalent) or a small brass, mild steel, or aluminum hammer, to detect bonding voids in accordance with Part 1—Inspection of the HTC Mandatory Service Bulletin Notice No. 3100-4R4, dated May 10, 2006. Modifying each T/R blade by installing a titanium rivet, P/N 500P3124-13, in the tip of the T/R blade and painting a “T” in the root-end of the T/R blade would be a terminating action for this AD. The actions would be required to be accomplished by following the specified portions of the HTC service bulletin described previously.

We estimate that this proposed AD would affect 718 helicopters of U.S. registry.

  • If operators conduct the repetitive inspections required by this AD instead of modifying their T/R blades by installing a titanium rivet, the estimated costs per year would be $229,760 per year, assuming:
  • 24 inspections per year per helicopter (600 hours TIS per 25 hour TIS inspection), * Labor of 5 minutes per T/R blade (10 minutes (1/6 hour) per helicopter), and
  • An average labor rate of $80 per work hour.
  • If operators elect to implement the terminating action by installing a titanium rivet in each T/R blade, the estimated total cost would be $244,120, assuming:
  • The cost of removing, reinstalling, and balancing the 2-T/R blade set for the entire fleet would be $114,880, assuming that it would take 2 work hours per helicopter to perform these actions at an average labor rate of $80 per work hour, and
  • The cost of installing the rivet in each T/R blade in the fleet would be $129,240, which includes the cost of $10 per rivet ($20 per helicopter), 1 work hour per T/R blade (2 work hours per helicopter) to install a rivet, at an average labor rate of $80 per work hour.

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 AD Docket 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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

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:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

MD Helicopters, Inc. (MDHI): Docket No. FAA-2008-0287; Directorate Identifier 2006-SW-15-AD.

Applicability

Model 369A, OH-6A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, and 369HS, certificated in any category, with a tail rotor (T/R) blade installed as follows including all serial numbers and those T/R blades with an “M” or an “I” painted on the T/R blade root:

  • Helicopter Technology Company, LLC (HTC) part number (P/N) 500P3100-101 and -103, or MDHI P/N 369D21640-501, -503, and -505.
  • HTC P/N 500P3100-301 and -303, or MDHI P/N 369D21641-501, -503, and -505.
  • HTC P/N 500P3300-501 and -503, or MDHI P/N 369D21643-501, -503, and -505.
  • HTC P/N 500P3500-701 and -703, or MDHI P/N 369D21642-501, -503, and -505.

Note 1:

An “M” or an “I” painted on the root of the T/R blade indicates compliance to an Alternate Method of Compliance (AMOC) to Emergency AD 2003-08-51 (Docket No. 2003-SW-17-AD, Amendment 39-13215, April 15, 2003), issued by the FAA, Los Angeles Aircraft Certification Office (LAACO) on June 13, 2003 to HTC. The AMOC addressed shot peening of the pitch horn of the T/R assembly.

Compliance

Required as indicated.

To prevent disbonding and subsequent separation of an abrasion strip from a T/R blade, which could result in vibration, loss of the T/R, and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 25 hours time-in-service (TIS), unless accomplished previously, and thereafter at intervals not to exceed 25 hours TIS, inspect the abrasion strip-to-skin bond integrity on each T/R blade using a tap test method in accordance with Part 1—Inspection, in Helicopter Technology Company, LLC (HTC) Mandatory Service Bulletin Notice No. 3100-4R4, dated May 10, 2006 (SB).

Note 2:

MD Helicopters Service Bulletin SB369D-203R1, SB369E-097R1, SB369F-082R1, and SB369H-246R1, dated January 23, 2006, pertain to the subject of this AD.

(b) Modifying each T/R blade in accordance with FAA-approved data by installing a titanium rivet at the outboard end and painting the letter “T” on the root-end of the T/R blade to indicate the modification has been accomplished is considered a terminating action for the requirements of this AD.

(c) 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: John Cecil, Aviation Safety Engineer, 3960 Paramount Blvd., Lakewood, California 90712-4137, telephone (562) 627-5228, fax (562) 627-5210, for information about previously approved alternative methods of compliance.

(d) Special flight permits will not be issued.

Start Signature
Start Printed Page 13518

Issued in Fort Worth, Texas, on March 4, 2008.

David A. Downey,

Manager, Rotorcraft Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. E8-5068 Filed 3-12-08; 8:45 am]

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