Document ID: FAA-2017-1125-0006
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: MD Helicopters Inc. Helicopters
Posted Date: 2020-03-24T04:00Z

[Federal Register Volume 85, Number 57 (Tuesday, March 24, 2020)]
[Rules and Regulations]
[Pages 16531-16533]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-05996]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-1125; Product Identifier 2017-SW-078-AD; Amendment 
39-19880; AD 2020-06-11]
RIN 2120-AA64

Airworthiness Directives; MD Helicopters Inc. Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for MD 
Helicopters Inc. (MDHI) Model 600N helicopters. This AD requires 
establishing a life limit for the main rotor (M/R) blade upper control 
collective/longitudinal link assembly (link assembly). This AD was 
prompted by the discovery that the life limit was omitted from the 
maintenance manual. The actions of this AD are intended to prevent an 
unsafe condition on these products.

DATES: This AD is effective April 28, 2020.

ADDRESSES: For service information related to this final rule, contact 
MD Helicopters, Inc., Attn: Customer Support Division, 4555 E. McDowell 
Rd., Mail Stop M615, Mesa, AZ 85215-9734; telephone 1-800-388-3378; fax 
480-346-6813; or at https://www.mdhelicopters.com. You may review this 
service information at the FAA, Office of the Regional Counsel, 
Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 
76177. For information on the availability of this material at the FAA, 
call 817-222-5110.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2017-
1125; or in person at Docket Operations between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays. The AD docket contains 
this AD, any comments received, and other information. The street 
address for Docket Operations is U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Payman Soltani, Aerospace Engineer, 
Airframe Section, Los Angeles ACO Branch, Compliance and Airworthiness 
Division, FAA, 3960 Paramount Blvd., Lakewood, California 90712; 
telephone 562-627-5313; email payman.soltani@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to MDHI Model 600N 
helicopters with a yaw stability augmentation system and with an M/R 
link assembly part number (P/N) 600N7617-1 installed. The NPRM 
published in the Federal Register on September 10, 2018 (83 FR 45580). 
The NPRM was prompted by a report from MDHI that during a review of the 
Airworthiness Limitations section of the applicable maintenance manual, 
MDHI discovered that it did not include a life limit for link 
assemblies installed on MDHI Model 600N helicopters with a yaw 
stability augmentation system. Link assembly P/N 600N7617-1, which is 
made of aluminum, is a life-limited part with a life limit of 15,000 
hours time-in-service (TIS). MDHI subsequently revised the 
Airworthiness Limitations section of the maintenance manual to include 
the life limit. The NPRM proposed to require creating a component 
history card or equivalent record for each affected link assembly, if 
one does not exist, and recording a life limit of 15,000 hours TIS. 
This NPRM also proposed to require determining the hours TIS of the 
link assembly and removing the link assembly from service according to 
the new life limit. The proposed requirements were intended to prevent 
a link assembly remaining in service beyond its life limit, which could 
result in fatigue failure, loss of M/R blade pitch control, and 
subsequent loss of helicopter control.

Comments

    The FAA gave the public the opportunity to participate in 
developing this final rule. The following presents the comments 
received on the NPRM and the FAA's response to each comment.

Request

    MDHI expressed concern that the requirements proposed by the NPRM 
do not definitively eliminate the risk of a life limit being exceeded.
    MDHI stated that link assembly P/N 600N7617-1 is not serialized and 
is aware that link assemblies have been installed on aircraft with 
multiple serial numbers, possibly indicating that link assemblies P/N 
600N7617-1 may not have a reliable TIS record. MDHI also stated if the 
TIS is unknown, arbitrarily setting the TIS to the aircraft hours may 
not adequately reflect the actual TIS of link assembly P/N 600N7617-1.

FAA Response

    The FAA acknowledges link assembly P/N 600N7617-1 is not serialized 
and the possibility of cross-installation on multiple aircraft. 
However, the FAA has determined that using the hours TIS of the 
helicopter mitigates the risk to an acceptable level because there is a 
small number of link assemblies P/N 600N7617-1 in-service, the usage 
rate for MDHI Model 600N helicopters is similar throughout the fleet, 
and the 15,000 hours TIS life limit includes a built-in life reduction 
for different variabilities.

Request

    MDHI requested the FAA mandate the replacement of link assembly P/N 
600N7617-1 with link assembly P/N 600N7617-5. MDHI explained that 
installation of link assembly P/N 600N7617-5 is consistent with 
production and field modification installations of the yaw stability 
augmentation system (YSAS), which requires installation of link 
assembly P/N 600N7617-5, and that link assembly P/N 600N7617-5 is not 
subject to life-limiting fatigue, therefore eliminating this potential 
safety risk.

FAA Response

    The FAA agrees that replacing link assembly P/N 600N7617-1 with 
link assembly P/N 600N7617-5 is beneficial but disagrees that the 
replacement is required for airworthiness. Link

[[Page 16532]]

assembly P/N 600N7617-5 is an upgraded part made of steel and is not 
subject to a life limit. The FAA disagrees with requiring replacement 
of link assembly P/N 600N7617-1 with link assembly P/N 600N7617-5 
because link assembly P/N 600N7617-1 is airworthy within the life limit 
of 15,000 TIS. The FAA provided additional information about this 
response, which can be found in the AD docket. The FAA has added an 
optional terminating action to the requirements of this AD that 
specifies removing link assembly P/N 600N7617-1 from service and 
installing link assembly P/N 600N7617-5 instead.

FAA's Determination

    The FAA has reviewed the relevant data, considered the comments 
received, and determined that air safety and the public interest 
require adopting this final rule as proposed except for the changes 
described previously. These changes are consistent with the intent that 
was proposed in the NPRM to address the unsafe condition and do not add 
any additional burden upon the public to that already proposed in the 
NPRM. The FAA has also determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
this final rule.

Related Service Information

    The FAA reviewed MDHI CSP-HMI-2 MDHI Maintenance Manual, Chapter 
04, Airworthiness Limitations, Revision 47, dated September 30, 2016. 
This service information specifies a 15,000 hour TIS life limit for 
link assembly P/N 600N7617-1 for helicopters with a yaw stability 
augmentation system.

Costs of Compliance

    The FAA estimates that this AD affects 26 helicopters of U.S. 
Registry. The FAA estimates that operators may incur the following 
costs in order to comply with this AD. Labor costs are estimated at $85 
per work-hour.
    Determining the hours TIS of each link assembly and updating the 
aircraft records takes about 30 minutes, for a cost of $43 per 
helicopter and $1,118 for the U.S. fleet.
    Replacing a link assembly, if needed, takes about 2 work-hours, and 
parts cost about $984 for an estimated replacement cost of $1,154 per 
link per helicopter.

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.
    The FAA is 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) Will not affect intrastate aviation in Alaska, 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.

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):

2020-06-11 MD Helicopters Inc.: Amendment 39-19880; Docket No. FAA-
2017-1125; Product Identifier 2017-SW-078-AD.

(a) Applicability

    This AD applies to MD Helicopters Inc. (MDHI) Model 600N 
helicopters, certified in any category, with a yaw stability 
augmentation system and with a main rotor (M/R) blade upper control 
collective/longitudinal link assembly (link assembly) part number 
(P/N) 600N7617-1 installed.

(b) Unsafe Condition

    This AD defines the unsafe condition as a link assembly 
remaining in service beyond its fatigue life. This condition could 
result in failure of the link assembly, failure of M/R blade pitch 
control, and subsequent loss of helicopter control.

(c) Effective Date

    This AD becomes effective April 28, 2020.

(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

    Within 100 hours time-in-service (TIS):
    (1) Determine the total hours TIS of each link assembly P/N 
600N7617-1. If the hours TIS are unknown, use the hours TIS of the 
helicopter. Remove from service any link assembly that has 15,000 or 
more hours TIS. Thereafter, remove from service any link assembly 
before accumulating 15,000 hours TIS.
    (2) Create a component history card or equivalent record for 
each link assembly P/N 600N7617-1 and record a life limit of 15,000 
hours TIS.
    (3) As an optional terminating action to the requirements of 
paragraphs (e)(1) and (2) of this AD, you may remove from service 
link assembly P/N 600N7617-1 and install link assembly P/N 600N7617-
5.

(f) Special Flight Permits

    Special flight permits are prohibited.

(g) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles ACO Branch, FAA, may approve AMOCs 
for this AD. Send your proposal to: Payman Soltani, Aerospace 
Engineer, Airframe Section, Los Angeles ACO Branch, Compliance and 
Airworthiness Division, FAA, 3960 Paramount Blvd., Lakewood, 
California 90712; telephone 562-627-5313; email 9-ANM-LAACO-AMOC-REQUESTS@faa.gov.
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, the FAA suggests 
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.

(h) Additional Information

    For service information related to this AD, contact MD 
Helicopters, Inc., Attn: Customer Support Division, 4555 E. McDowell 
Rd., Mail Stop M615, Mesa, AZ 85215-9734; telephone 1-800-388-3378; 
fax 480-346-6813; or at https://www.mdhelicopters.com. You may 
review a copy of this service information at the FAA, Office of the 
Regional Counsel, Southwest Region, 10101

[[Page 16533]]

Hillwood Pkwy, Room 6N-321, Fort Worth, TX 76177.

(i) Subject

    Joint Aircraft Service Component (JASC) Code: 6710, Main Rotor 
Control.

    Issued on March 17, 2020.
Gaetano A. Sciortino,
 Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2020-05996 Filed 3-23-20; 8:45 am]
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