Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters

[Federal Register Volume 69, Number 224 (Monday, November 22, 2004)]
[Rules and Regulations]
[Pages 67805-67807]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-25542]



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Federal Register / Vol. 69, No. 224 / Monday, November 22, 2004 / 
Rules and Regulations

[[Page 67805]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19613; Directorate Identifier 2004-SW-38-AD; 
Amendment 39-13870; AD 2004-23-15]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, Inc. Model MD900 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD) for 
the MD Helicopters, Inc. (MDHI) Model MD900 helicopters. This action 
requires reducing the life limit of certain Notar fan system tension-
torsion (TT) straps. This action also requires, at a specified time 
interval, removing each affected TT strap from the helicopter, doing a 
visual and x-ray inspection, and replacing any unairworthy part before 
further flight. Reporting the discovery of any unairworthy TT strap is 
also required. This amendment is prompted by two recent in-flight TT 
strap failures. The actions specified in this AD are intended to 
prevent failure of a TT strap resulting in loss of directional control 
and subsequent loss of control of the helicopter.

DATES: Effective December 7, 2004.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 7, 2004.
    Comments for inclusion in the Rules Docket must be received on or 
before January 21, 2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD:
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically;
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically;
    <bullet> Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590;
    <bullet> Fax: (202) 493-2251; or
    <bullet> Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    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-GO48, Mesa, Arizona 85215-9734, telephone 1-800-
388-3378, fax 480-891-6782, or on the Web at http://www.mdhelicopters.com. You may examine this information 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.

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 Management System (DMS) Docket Offices between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The Docket 
Office (telephone (800) 647-5227) is located on the plaza level of the 
Department of Transportation Nassif 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: Roger Durbin, Aviation Safety 
Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe 
Branch, 3960 Paramount Blvd., Lakewood, California 90712, telephone 
(562) 627-5233, fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: This amendment adopts a new AD applicable to 
MDHI Model MD900 helicopters with a TT strap, part number (P/N) 
900R3442009-103, 900R6442009-103, 900R3442009-101, or 500N5311-5, 
installed. This action requires:
    <bullet> Before further flight, for TT strap, P/N 900R3442009-103 
and 900R6442009-103, reducing the life limit from 3034 to 2500 hours 
time-in-service (TIS);
    <bullet> Within 10 hours TIS, for any TT strap that has accumulated 
1190 or more hours TIS, doing a visual and x-ray inspection of each TT 
strap and replacing any unairworthy part before further flight;
    <bullet> Before the TT strap accumulates 1200 hours TIS, for any TT 
strap with less than 1190 hours TIS, doing a visual and x-ray 
inspection of each strap and replacing any unairworthy part before 
further flight; and
    <bullet> Within 7 days, reporting information about any unairworthy 
TT strap to Roger Durbin, Aviation Safety Engineer, FAA, Los Angeles 
Aircraft Certification Office, Airframe Branch, 3960 Paramount Blvd., 
Lakewood, California 90712, telephone (562) 627-5233, fax (562) 627-
5210.

This amendment is prompted by two recent in-flight TT strap failures. 
The cause of the failures is not known at this time, and this AD is 
interim action. We will consider further rulemaking once our 
investigation is complete. The actions specified in this AD are 
intended to prevent failure of a TT strap resulting in loss of 
directional control and subsequent loss of control of the helicopter.
    We have reviewed MD Helicopters Service Bulletin SB-900-095, dated 
November 3, 2004. The service bulletin advises of the reduction of the 
TT strap life limit and describes procedures for performing an 
inspection of each TT strap for nicks, cuts, cracks, or wear. 
Procedures for a Level II or higher X-Ray Technician to do and 
interpret an x-ray inspection of each TT strap for progressive fiber 
fractures are also included in the service bulletin.
    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 TT strap resulting in loss of directional 
control and subsequent loss of control of the helicopter. This AD 
requires, before further flight, reducing the life limit of

[[Page 67806]]

certain part-numbered TT straps. This AD also requires, depending on 
the hours accumulated on the TT strap, doing a visual and x-ray 
inspection within 10 hours TIS or before the accumulation of 1200 hours 
TIS and replacing any unairworthy part before further flight. Reporting 
the discovery of any unairworthy TT strap is also required. 
Accomplishing the inspections in accordance with the previously 
described service bulletin is required. The short compliance time 
involved is required because the previously described critical unsafe 
condition can adversely affect the controllability of the helicopter. 
Therefore, reducing the TT strap life limit before further flight, 
inspecting each TT strap at the specified time interval, and reporting 
information about any unairworthy TT strap is required within 7 days, 
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 31 helicopters. It will take 
approximately 7 work hours for each inspection and replacement at an 
average labor rate of $65 per work hour. It will also cost $100 for 
each x-ray inspection. Required parts will cost approximately $757 per 
TT strap replacement. Based on these figures, we estimate the total 
cost impact of the AD on U.S. operators to be $40,672 (assuming a 
visual and x-ray inspection on each helicopter and a TT strap 
replacement on 8% of the 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-2004-19613; 
Directorate Identifier 2004-SW-38-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.
    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.

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

0
1. The authority citation for part 39 continues to read as follows:

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


Sec.  39.13  [Amended]

0
2. Section 39.13 is amended by adding a new airworthiness directive to 
read as follows:

2004-23-15 MD Helicopters, Inc.: Amendment 39-13870. Docket No. FAA-
2004-19613; Directorate Identifier 2004-SW-38-AD.

    Applicability: Model MD900 helicopters, with a Notar fan system 
that has a tension-torsion (TT) strap, part number (P/N) 
900R3442009-103, 900R6442009-103, 900R3442009-101, or 500N5311-5, 
installed, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of a TT strap in the Notar fan system, which 
could result in loss of directional control and subsequent loss of 
control of the helicopter, accomplish the following:
    (a) Before further flight, for TT straps, P/N 900R3442009-103 
and 900R6442009-103, reduce the life limit from 3034 to 2500 hours 
time-in-service (TIS).
    (b) Within 10 hours TIS, for any TT strap that has accumulated 
1190 or more hours TIS, remove the TT strap from the helicopter and 
do a visual and x-ray inspection in accordance with the Inspection 
Instructions, paragraph 2.B.(1). through (5). and Figures 1 and 2 of 
MD Helicopters Service Bulletin SB900-095, dated November 3, 2004 
(SB). Replace any unairworthy part before further flight.
    (c) Before the TT strap accumulates 1200 hours TIS, for any TT 
strap with less than 1190 hours TIS, remove the TT strap from the 
helicopter and do a visual and x-ray inspection in accordance with 
the Inspection Instructions, paragraph 2.B.(1). through (5). and 
Figures 1 and 2 of the SB. Replace any unairworthy part before 
further flight.
    (d) The x-ray inspection of the TT strap must be performed by a 
Level II or higher x-ray technician who is qualified under the 
guidelines established by MIL-STD-410E, ATA Specification 105, AIA-
NAS-410, or an FAA-accepted equivalent for qualification standards.
    (e) Within 7 days, for any TT strap that you find unairworthy, 
report the helicopter serial number (S/N), the TT strap P/N and S/N, 
the total hours TIS on the TT strap, and a description of the part 
condition rendering it unairworthy. Report the information to Roger 
Durbin, Aviation Safety Engineer, FAA, Los Angeles Aircraft 
Certification Office, Airframe Branch, 3960 Paramount Blvd., 
Lakewood, California 90712, telephone (562) 627-5233, fax (562) 627-
5210.
    (f) Information collection requirements contained in this AD 
have been approved by the Office of Management and Budget (OMB) 
under the provisions of the Paperwork Reduction Act of 1980 (44 
U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-
0056.
    (g) This AD revises the Airworthiness Limitations section of the 
maintenance manual by reducing the life limit of the TT strap, P/N 
900R3442009-103 and 900R6442009-103, from 3034 hours TIS to 2500 
hours TIS.
    (h) 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 Los Angeles Aircraft Certification, Transport Airplane 
Directorate, FAA, for information about previously approved 
alternative methods of compliance.
    (i) The inspections shall be done in accordance with MD 
Helicopters Service Bulletin SB900-095, dated November 3, 2004. The 
Director of the Federal Register approved this incorporation by 
reference in accordance with 5 U.S.C. 552(a) and 1 CFR

[[Page 67807]]

part 51. Copies may be obtained from MD Helicopters Inc., Attn: 
Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615-
GO48, Mesa, Arizona 85215-9734, telephone 1-800-388-3378, fax 480-
891-6782, or on the web at www.mdhelicopters.com. Copies may be 
inspected 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.
    (j) This amendment becomes effective on December 7, 2004.

    Issued in Fort Worth, Texas, on November 10, 2004.
Kim Smith,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 04-25542 Filed 11-19-04; 8:45 am]
BILLING CODE 4910-13-U

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