[Federal Register Volume 71, Number 167 (Tuesday, August 29, 2006)]
[Rules and Regulations]
[Pages 51095-51096]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-14291]



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  Federal Register / Vol. 71, No. 167 / Tuesday, August 29, 2006 / 
Rules and Regulations  

[[Page 51095]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24631; Directorate Identifier 2005-SW-01-AD; 
Amendment 39-14739; AD 2006-18-01]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, Inc. Model MD900 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD) for MD Helicopters, Inc. (MDHI) Model MD900 helicopters, that 
currently requires reducing the life limit of certain Notar fan system 
tension-torsion (TT) straps. That existing AD 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. This amendment requires the 
same actions as the existing AD, but also requires revising the life 
limit on the component history card or equivalent record and doing 
repetitive visual and X-ray inspections, and removes reporting 
requirements. This amendment is prompted by two in-flight TT strap 
failures. The actions specified by this AD are intended to prevent 
failure of a TT strap, loss of directional control, and subsequent loss 
of control of the helicopter.

DATES: Effective October 3, 2006.
    The incorporation by reference of MD Helicopters Service Bulletin 
SB900-095, dated November 3, 2004, was approved previously by the 
Director of the Federal Register as of December 7, 2004 (69 FR 67806, 
November 22, 2004).

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 1-
800-388-3378, fax 480-346-6813, or on the web 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://dms.dot.gov, or at the 
Docket Management System (DMS), U.S. Department of Transportation, 400 
Seventh Street, SW., Room PL-401, on the plaza level of the Nassif 
Building, Washington, DC.

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: A proposal to amend 14 CFR part 39 by 
superseding AD 2004-23-15, Amendment 39-13870 (69 FR 67805, November 
22, 2004), for MDHI Model MD900 helicopters, was published in the 
Federal Register on May 10, 2006 (71 FR 27212). The action proposed to 
require the following for MDHI Model MD900 helicopters with a TT strap, 
part number (P/N) 900R3442009-103, 900R6442009-103, 900R3442009-101, or 
500N5311-5, installed:
     Before further flight, unless accomplished previously, for 
TT strap, P/N 900R3442009-103 and 900R6442009-103, reducing the life 
limit from 3,034 to 2,500 hours TIS and revising the life limit on the 
component history card or equivalent record;
     Within 10 hours TIS, unless accomplished previously, and 
then at intervals not to exceed 300 hours TIS, for any TT strap that 
has accumulated 1,190 or more hours TIS, doing a visual and X-ray 
inspection of each TT strap and replacing any unairworthy TT strap 
before further flight; and
     Before the TT strap accumulates 1,200 hours TIS, and then 
at intervals not to exceed 300 hours TIS, for any TT strap with less 
than 1,190 hours TIS, doing a visual and X-ray inspection of each strap 
and replacing any unairworthy TT strap before further flight.
    At the time that we issued AD 2004-23-15, the cause of the TT strap 
failures was not known, and that AD was considered interim action. The 
actions required by this AD are also are interim actions, because the 
cause of the failures is still unknown and the investigation is 
ongoing. We will consider further rulemaking once our investigation is 
complete.
    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 the 
adoption of the rule as proposed, with one change--contact information 
for the FAA has been added to paragraph (f) of the AD. The FAA has 
determined that this change will neither increase the economic burden 
on any operator nor increase the scope of the AD.
    The FAA estimates that this AD will affect 31 helicopters of U.S. 
registry, and the required actions will take approximately 7 work hours 
for each visual inspection and replacement at an average labor rate of 
$65 per work hour. Because you must remove the TT strap to inspect it, 
there is no additional labor cost for replacing the TT strap. It will 
also cost $100 for each X-ray inspection. Required parts will cost 
about $757 to replace each strap. Based on these figures, we estimate 
the total cost impact of this AD on U.S. operators to be $168,950 in 
the first year (assuming a total of 5 TT straps are replaced per 
helicopter and 3 visual inspections and 3 X-ray inspections are 
conducted the first year for each helicopter).

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

[[Page 51096]]

    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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
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 removing Amendment 39-13870 (69 FR 
67805, November 22, 2004), and by adding a new airworthiness directive 
(AD), Amendment 39-14739, to read as follows:

2006-18-01 MD Helicopters, Inc.: Amendment 39-14739. Docket No. FAA-
2006-24631; Directorate Identifier 2005-SW-01-AD. Supersedes AD 
2004-23-15, 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.
    To prevent failure of a TT strap in the Notar fan system, loss 
of directional control, and subsequent loss of control of the 
helicopter, accomplish the following:
    (a) Before further flight, unless accomplished previously, for 
TT Straps, P/N 900R3442009-103 and 900R6442009-103, reduce the life 
limit from 3,034 to 2,500 hours time-in-service (TIS) and revise the 
life limit on the component history card or equivalent record to 
reflect this reduced retirement life.
    (b) Within 10 hours TIS, unless accomplished previously, for any 
TT strap that has accumulated 1,190 or more hours TIS, and then at 
intervals not to exceed 300 hours TIS, remove the TT strap from the 
helicopter and do a visual and an 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 TT strap before 
further flight.
    (c) Before the TT strap accumulates 1,200 hours TIS, for any TT 
strap with less than 1,190 hours TIS, and then at intervals not to 
exceed 300 hours TIS, remove the TT strap from the helicopter and do 
a visual and an 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 TT strap 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) This AD revises the Airworthiness Limitations section of the 
maintenance manual by reducing the life limit of the TT straps, P/N 
900R3442009-103 and 900R6442009-103, from 3,034 hours TIS to 2,500 
hours TIS. Additionally, this AD revises the Airworthiness 
Limitations section of the maintenance manual by adding repetitive 
inspection requirements at intervals not to exceed 300 hours TIS for 
TT straps, P/N 900R3442009-103, 900R6442009-103, 900R3442009-101, 
and 500N5311-5, that have 1,200 or more hours TIS until the TT strap 
reaches its retirement life.
    (f) 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, FAA, ATTN: 
Roger Durbin, Aviation Safety Engineer, Airframe Branch, 3960 
Paramount Blvd., Lakewood, California 90712, telephone (562) 627-
5233, fax (562) 627-5210, for information about previously approved 
alternative methods of compliance.
    (g) The X-ray inspection shall be done in accordance with the 
specified portions of MD Helicopters Service Bulletin SB900-095, 
dated November 3, 2004. The incorporation by reference of that 
document was approved previously by the Director of the Federal 
Register, in accordance with 5 U. S.C. 552(a) and 1 CFR part 51, as 
of December 7, 2004 (69 FR 67806, November 22, 2004). Copies may be 
obtained from MD Helicopters Inc., Attn: Customer Support Division, 
4555 E. McDowell Rd., Mail Stop M615, Mesa, Arizona 85215-9734, 
telephone 1-800-388-3378, fax 480-346-6813, or on the web at http://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.
    (h) This amendment becomes effective on October 3, 2006.

    Issued in Fort Worth, Texas, on August 22, 2006.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
 [FR Doc. E6-14291 Filed 8-28-06; 8:45 am]
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