[Federal Register Volume 72, Number 114 (Thursday, June 14, 2007)]
[Rules and Regulations]
[Pages 32788-32791]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-11393]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-SW-37-AD; Amendment 39-15101; AD 2007-12-23]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, Inc. Model 369A, 369D, 
369E, 369F, 369FF, 369H, 369HE, 369HS, 369HM, 500N, and OH-6A 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) for 
MD Helicopters, Inc. (MDHI) Model 369A, 369D, 369E, 369F, 369FF, 369H, 
369HE, 369HS, 369HM, 500N, and OH-6A helicopters that requires 
inspecting each landing gear fairing support assembly (support 
assembly), replacing or reworking certain forward and aft landing gear 
assemblies, and creating an access hole to facilitate inspections and a 
recurring inspection. A terminating action for the requirements of this 
AD is also provided. This amendment is prompted by five reports of 
landing gear strut (strut) failures. The actions specified by this AD 
are intended to detect a crack that could result in the failure of a 
strut and subsequent loss of control of the helicopter during landing.

DATES: Effective July 19, 2007.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 19, 2007.

ADDRESSES: The service information referenced in this AD may be 
obtained from MD Helicopters Inc., Attn: Customer Support Division, 
4555 E. McDowell Rd., Mail Stop M615, Mesa,

[[Page 32789]]

Arizona 85215-9734, telephone 1-800-388-3378, fax 480-346-6813, or on 
the Web at http://www.mdhelicopters.com. This information may be 
examined at the FAA, Office of the Regional Counsel, Southwest Region, 
2601 Meacham Blvd., Room 663, Fort Worth, Texas.

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.

SUPPLEMENTARY INFORMATION: A proposal to amend 14 CFR part 39 to add an 
AD for the specified MDHI model helicopters was published as a Notice 
of Proposed Rulemaking (NPRM) in the Federal Register on August 4, 2004 
(69 FR 47040). That NPRM would have required removing all landing gear 
fairings; determining the number and location of rivets that attach the 
landing gear fairing support assembly to the landing gear strut; and if 
three rivets (forward, aft and inboard) are present, replacing or 
reworking the landing gear assembly. If only the forward and aft rivets 
are present, no rework would be required by the proposed AD. That NPRM 
was prompted by five reports of strut failures. Operators of the 
helicopters with failed struts do not fall into any clear category of 
service. For example, one was a tour operator in Niagara Falls, New 
York, and another was a police department operator in Calgary, Canada. 
In its original design, the fairing support was attached to the strut 
with three rivets (forward, aft, and outboard). In 1994, the 
manufacturer released a design change to attach the fairing support 
assembly with only forward and aft rivets because of the possibility of 
reduced service life of the strut if the third rivet was located on the 
inboard side of the strut. Some landing gear struts entered service 
with an additional rivet hole drilled on the inboard side of the strut. 
This additional rivet hole results in decreased fatigue strength of the 
strut and subsequent cracking. That condition, if not corrected, could 
result in cracking of the forward and aft struts, failure of a strut, 
and subsequent loss of control of the helicopter during landing.
    After issuing that NPRM, we received several comments from 2 
commenters and we agreed that we should make some changes to the NPRM. 
Because some of those changes expanded the scope of the NPRM, we 
determined that it was necessary to reopen the comment period to 
provide additional opportunity for public comment. Therefore, a 
Supplemental NPRM (SNPRM) was published in the Federal Register on 
January 8, 2007 (72 FR 666). The SNPRM revised the NPRM by proposing to 
mandate both the creation of an access hole to facilitate inspections 
and a recurring inspection. The SNPRM also proposed excluding from the 
applicability certain helicopters modified with a certain Supplemental 
Type Certificate (STC) and provided a terminating action for the 
proposed requirements. The SNPRM also included clarifying changes.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the SNPRM 
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 except we have expanded the contact address in 
paragraph (d) in the body of the AD to provide more information to the 
public and have made minor editorial changes. These changes will 
neither increase the economic burden on any operator nor increase the 
scope of this AD.
    The FAA has reviewed MD Helicopters Service Bulletin SB369H-244, 
SB369E-094, SB500N-022, SB369D-200, and SB369F-078, dated April 7, 
2000, which describes procedures for determining the number and 
location of rivets attaching the landing gear fairing support assembly 
to the landing gear strut. Where three rivets are present, instructions 
are provided to rework the landing gear assembly and replace any 
cracked strut assembly.
    The FAA estimates that this AD will affect 651 helicopters of U.S. 
registry. Determining the number of rivets and initially inspecting 
each affected ``3-hole'' strut and fairing will take approximately 2 
work hours, installing a new strut will take approximately 1.5 work 
hours, and reworking a strut will take 1 work hour. Each repetitive 
inspection will take 1/4 work hour per strut (1 hour per helicopter for 
each of 4 struts). The average labor rate is $80 per work hour. 
Required parts (new struts) will cost approximately $2,838 for each 
forward strut, $2,574 for each aft strut, and $97 for a modification 
kit to install an inspection hole. Assuming that each helicopter has an 
initial inspection, that all 651 helicopters are modified, that 325 
helicopters have two struts reworked, that 5 helicopters require 2 new 
forward struts, and that 2 repetitive inspections are required per 
year, the total estimated cost of the AD on U.S. operators is about 
$353,047 ($248,887 for the initial inspections, modification, and 
parts, and $104,160 for the repetitive inspections).

Regulatory Findings

    The regulations adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

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:

[[Page 32790]]

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:

2007-12-23 MD Helicopters, Inc.: Amendment 39-15101. Docket No. 
2003-SW-37-AD.

Applicability

    Model 369A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HS, 369HM, 
500N, and OH-6A helicopters, with any of the components listed in 
the Applicability Table installed, excluding any helicopter with 
Aerometals strut (part number (P/N) 369XH6001-41, -42, -51, or -52) 
installed in accordance with Supplemental Type Certificate (STC) No. 
SR00981LA, certificated in any category:

                           Applicability Table
------------------------------------------------------------------------
        Component name                 Component part No.  (P/N)
------------------------------------------------------------------------
Mid Aft Fairing Assembly.....  369H6200-61, -62, standard gear.
Aft Support Assembly.........  369H6200-23, -24 (-23 to be reinstalled
                                on the right-hand side and -24 to be
                                reinstalled on the left-hand side, all
                                configurations).
Aft Fairing Assembly.........  369H92113-91, -92, extended gear.
Aft Filler Assembly..........  369H92113-131, -132, extended gear.
Aft Fillet Assembly..........  369A6200-45, -46, standard gear.
Aft Fillet Assembly..........  369H92113-111, -112, extended gear.
Mid Fwd Fairing Assembly.....  369H6200-41, -42, standard gear.
Fwd Fairing Assembly.........  369H92113-81, -82, extended gear.
Fwd Support Assembly.........  369H6200-23, -24 (-23 becomes right-hand
                                side and -24 becomes left-hand side).
Fwd Filler Assembly..........  369H92113-121, -122, extended gear.
Fwd Fillet Assembly..........  369A6200-57, -58, standard gear.
Fwd Fillet Assembly..........  369H92113-101, -102, extended gear.
------------------------------------------------------------------------

Compliance

    Required as indicated.
    To detect a crack that could result in the failure of a strut 
and subsequent loss of control of the helicopter during landing, 
accomplish the following:
    (a) Within 4 months, unless accomplished previously, remove all 
landing gear fairings (fairings) and inspect each landing gear 
fairing support assembly (support assembly) to determine the number 
and location of the rivets attaching the support assembly to the 
landing gear strut assembly (strut assembly).
    (1) If three rivets (forward, aft and inboard) are used to 
attach the support assembly to the strut assembly,
    (i) For each FORWARD landing gear assembly, remove the landing 
gear fillet assembly (fillet assembly), the three rivets, and the 
support assembly, and clean and dye-penetrant inspect the area in 
and around the 0.125 (3.18mm) diameter hole in the inboard surface 
of the strut assembly.
    (A) If the strut assembly is cracked, replace the cracked strut 
assembly with an airworthy strut assembly and install the other 
landing gear components in accordance with steps (6) through (11) of 
paragraph C of the Accomplishment Instructions of MD Helicopters 
Service Bulletin SB369H-244, SB369E-094, SB500N-022, SB369D-200, and 
SB369F-078, dated April 7, 2000 (SB).
    (B) If the strut assembly is not cracked, rework the landing 
gear assembly and install the other landing gear components in 
accordance with steps (5) through (11) of paragraph C of the 
Accomplishment Instructions of the SB.
    (ii) For each AFT landing gear assembly, remove the fillet 
assembly, the three rivets, and the support assembly, and clean and 
dye-penetrant inspect the area in and around the 0.125 (3.18mm) 
diameter hole in the inboard surface of the strut assembly.
    (A) If the strut assembly is cracked, replace the cracked strut 
assembly with an airworthy strut assembly and install the other 
landing gear components in accordance with steps (6) through (13) of 
paragraph B of the Accomplishment Instructions of the SB.
    (B) If the strut assembly is not cracked, rework the landing 
gear assembly and install the other landing gear components in 
accordance with steps (5) through (13) of Paragraph B of the 
Accomplishment Instructions of the SB.
    (2) If only two rivets (forward and aft) are used to attach the 
support assembly to the strut assembly and a third rivet hole has 
not been drilled in the strut, neither the inspection of the strut 
assembly nor the rework of those landing gear assemblies is required 
by this AD.
    (b) At intervals not to exceed 100 hours TIS or during each 
annual inspection, whichever occurs first, for any strut assembly 
that has a third rivet hole, remove the fairing inspection button 
plug and clean and inspect the area in and around the rivet hole for 
cracks using a bright light and a 10x or higher magnifying glass.
    (1) If any FORWARD strut assembly is cracked, replace the 
cracked strut with an airworthy strut assembly.
    (2) If any AFT strut assembly is cracked, replace the cracked 
strut with an airworthy strut assembly.
    (c) Installing a strut assembly that has only 2 rivet holes is 
terminating action for the requirements of this AD.

    Note 1: For the Model 369D, 369E, 369F, 369FF, and 500N 
helicopters, the Handbook of Maintenance Instruction, Servicing and 
Maintenance, HMI, CSP-HMI-2, Chapter 32, Section 32-10-00, ``Landing 
Gear Strut Inspection'' pertains to the subject of this AD.


    Note 2: For the Model 369A (OH-6A), 369H, 369HE, 369HS, and 
369HM helicopters, the Basic Handbook of Maintenance Instructions 
CSP-H-2, Section 6, ``Landing Gear'' pertains to the subject of this 
AD.

    (d) 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, FAA, Los Angeles 
Aircraft Certification Office, Airframe Branch, 3960 Paramount 
Blvd., Lakewood, California 90712-4137, telephone (562) 627-5228, 
fax (562) 627-5210 for information about previously approved 
alternative methods of compliance.
    (e) The replacements and installations shall be done in 
accordance with the specified portions of MD Helicopters Service 
Bulletin SB369H-244, SB369E-094, SB500N-022, SB369D-200, and SB369F-
078, dated April 7, 2000. 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 1-800-388-3378, fax 
480-346-6813, or on the Web 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/

[[Page 32791]]

code--of--federal--regulations/ibr--locations.html.
    (f) This amendment becomes effective on July 19, 2007.

    Issued in Fort Worth, Texas, on June 5, 2007.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. E7-11393 Filed 6-13-07; 8:45 am]
BILLING CODE 4910-13-P