
[Federal Register Volume 78, Number 211 (Thursday, October 31, 2013)]
[Rules and Regulations]
[Pages 65195-65198]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-25702]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0486; Directorate Identifier 2010-SW-031-AD; 
Amendment 39-17622; AD 2013-20-16]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, Inc. (MDHI) Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for MDHI 
Model MD900 helicopters with certain main rotor blade (MRB) retention 
bolts (bolts) installed. This AD requires a daily check of the position 
of each bolt, a daily check and a repetitive inspection for a gap in 
each bolt, and, if necessary, removing and inspecting the bolt for a 
crack and replacing any cracked bolt with an airworthy bolt. This AD 
was prompted by multiple reports of in-service bolt failures. The 
actions are intended to prevent failure of a bolt, which could lead to 
loss of MRB structural integrity and subsequent loss of control of the 
helicopter.

DATES: This AD is effective December 5, 2013.

ADDRESSES: For service information identified in this AD, contact MDHI, 
Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, 
Mesa, AZ 85215-9734, telephone (800) 388-3378, fax (480) 346-6813, or 
at http://www.mdhelicopters.com. You may review a copy of the 
referenced service information at the FAA, Office of the Regional 
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the Docket Operations Office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the economic evaluation, any 
comments received, and other information. The street address for the 
Docket Operations Office (phone: 800-647-5527) is U.S. Department of 
Transportation, Docket Operations Office, M-30, West Building Ground 
Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Roger Durbin, Aerospace Engineer, FAA, 
Los Angeles Aircraft Certification Office, Airframe Branch, ANM-120L, 
3960 Paramount Blvd., Lakewood, CA 90712, telephone (562) 627-5233, fax 
(562) 627-5210, email roger.durbin@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    On June 14, 2013, at 78 FR 35773, the Federal Register published 
our notice of proposed rulemaking (NPRM), which proposed to amend 14 
CFR part 39 to add an AD that would apply to MDHI Model MD900 
helicopters with certain bolts installed. The NPRM proposed to require 
a daily check of the position of each bolt, a daily check and a 
repetitive inspection for a gap in each bolt, and, if necessary, 
removing and inspecting the bolt for a crack and replacing any cracked 
bolt with an airworthy bolt. The NPRM was prompted by multiple reports 
of in-service bolt failures. The proposed requirements were intended to 
prevent failure of a bolt, which could lead to loss of MRB structural 
integrity and subsequent loss of control of the helicopter.

Comments

    We gave the public the opportunity to participate in developing 
this AD, but we did not receive any comments on the NPRM (78 FR 35773, 
June 14, 2013).

FAA's Determination

    We have reviewed the relevant information and determined that an 
unsafe condition exists and is likely to exist or develop on other 
helicopters of the same type designs and that air safety and the public 
interest require adopting the AD requirements as proposed.

Related Service Information

    MDHI issued Alert Service Bulletin SB900-116R1, dated April 9, 2010 
(ASB SB900-116R1), which supersedes ASB SB900-116, dated February 24, 
2010 (ASB SB900-116).
    ASB SB900-116 specifies a repetitive check of the blade retention 
bolts, part number (P/N) 900R3100001-103 and 900R3100001-105, for a gap 
and, depending on the outcome of the inspection, removing and 
inspecting the bolt for damage. The ASB also specifies a repetitive 
force check of each bolt, P/N 900R3100001-103, and a torque check of 
each bolt, P/N 900R3100001-105. Lastly, the ASB specifies a daily 
preflight check of each bolt to examine the position of the bolt and 
for a gap, and, if any bolt has moved up or down or if there was no 
gap, removing and inspecting the bolt.
    Superseding ASB SB900-116R1 retains the same specifications as ASB 
SB90016, except that it revises the

[[Page 65196]]

interval for the bolt force and torque checks from 4-6 flight-hours to 
8-10 flight-hours. ASB SB90016R1 also revises the change of force or 
torque from not more than 10 percent to not more than 10 
percent.

Differences Between This AD and the Service Information

    This AD uses the term ``inspect'' when describing the action of 
inspecting a bolt for a crack and inspecting for a gap between the 
thrust washer and the retainer. The ASB uses the term ``check.''

Costs of Compliance

    We estimate that this AD will affect 29 helicopters in the U.S. 
registry. We estimate that operators may incur the following costs to 
comply with this AD: The average labor rate is $85 per work hour. It 
will take about .5 work hour to do a gap inspection of each bolt. It 
will take about 1 work hour to replace a cracked bolt and the required 
parts will cost $800 at a total cost per helicopter of $928.

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.

Regulatory Findings

    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 this AD:
    (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);
    (3) Will not affect intrastate aviation in Alaska to the extent 
that it justifies making a regulatory distinction; and
    (4) 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 and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2013-20-16 MD Helicopters, Inc. (MDHI): Amendment 39-17622; Docket 
No. FAA-2013-0486; Directorate Identifier 2010-SW-031-AD.

(a) Applicability

    This AD applies to Model MD 900 helicopters with a main rotor 
blade retention bolt (bolt), part number (P/N) 900R3100001-103 or 
900R3100001-105, installed; certificated in any category.

 (b) Unsafe Condition

    This AD defines the unsafe condition as bolt failure. This 
condition could result in loss of main rotor blade structural 
integrity and subsequent loss of control of the helicopter.

 (c) Effective Date

    This AD becomes effective December 5, 2013.

(d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(e) Required Actions

    (1) Before the first flight of each day:
    (i) Visually check each bolt for failure. Failure of a bolt may 
be indicated by movement of the bolt out of the bolt hole or by 
inconsistent extension of the bolt above or below the other bolts 
being inspected (a failed bolt migrates out of the bolt hole).
    (ii) Visually check for a gap between the thrust washer and the 
retainer, P/N 900R2100009-101 or -103. The thrust washer is depicted 
as item 2 and the retainer is depicted as item 8 in Figure 1 to 
paragraph (e) of this AD.
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[[Page 65197]]

[GRAPHIC] [TIFF OMITTED] TR31OC13.000

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    (iii) The actions required by paragraphs (e)(1)(i) and 
(e)(1)(ii) may be performed by the owner/operator (pilot) holding at 
least a private pilot certificate and must be entered into the 
aircraft maintenance records showing compliance with this AD in 
accordance with 14 CFR 43.9(a)(1)-(4) and 14 CFR 91.417(a)(2)(v). 
The record must be maintained as required by 14 CFR 91.417, 121.380, 
or 135.439.
    (iv) If there is any indication of bolt failure or if there is 
no gap between the thrust washer and retainer, before further 
flight, remove and inspect the bolt for a crack. Replace any cracked 
bolt with an airworthy bolt.
    (2) Within 300 hours time-in-service (TIS), and thereafter at 
intervals not to exceed 300 hours TIS, inspect each bolt for a gap 
between the thrust washer and the retainer.
    (i) Determine whether an O-ring is installed. Install any 
missing O-ring.
    (ii) If there is no gap between the thrust washer and retainer, 
before further flight, remove and inspect the bolt for a crack. 
Replace any cracked bolt with an airworthy bolt.
    (iii) If there is a gap between the thrust washer and retainer, 
measure the gap in two locations, 180 degrees apart, with a feeler 
gage. If the gap is more than 0.100 inch (2.54 mm) at either 
location, before further flight, remove and inspect the bolt for a 
crack. Replace any cracked bolt with an airworthy bolt.

(f) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles Aircraft Certification Office, 
Airframe Branch (ANM-120L), FAA, may approve AMOCs for this AD. Send 
your request to Roger Durbin, Aerospace Engineer, FAA, Los Angeles 
Aircraft Certification Office, Airframe Branch, ANM-120L, 3960 
Paramount Blvd., Lakewood, CA 90712, telephone (562) 627-5233, fax 
(562) 627-5210, email roger.durbin@faa.gov.

[[Page 65198]]

    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, we suggest that you 
notify your principal inspector or lacking a principal inspector, 
the manager of the local flight standards district office or 
certificate holding district office before operating any aircraft 
complying with this AD through an AMOC.

(g) Additional Information

    MDHI Alert Service Bulletin SB900-116R1, dated April 9, 2010, 
which supersedes MDHI Alert Service Bulletin SB SB900-116, dated 
February 24, 1010, neither of which is incorporated by reference, 
contains additional information about the subject of this AD. For 
service information identified in this AD, contact MDHI, Attn: 
Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, 
Mesa, AZ 85215-9734, telephone (800) 388-3378, fax (480) 346-6813, 
or at http://www.mdhelicopters.com. You may review copies of the 
service information at the FAA, Office of the Regional Counsel, 
Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas.

 (h) Subject

    Joint Aircraft System Component: 6210: Main rotor blade 
retention bolts.

    Issued in Fort Worth, Texas, on September 27, 2013.
Lance T. Gant,
Acting Directorate Manager, Rotorcraft Directorate, Aircraft 
Certification Service.
[FR Doc. 2013-25702 Filed 10-30-13; 8:45 am]
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