
[Federal Register Volume 82, Number 62 (Monday, April 3, 2017)]
[Proposed Rules]
[Pages 16138-16140]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-06460]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 82, No. 62 / Monday, April 3, 2017 / Proposed 
Rules  

[[Page 16138]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0270; Directorate Identifier 2016-SW-032-AD]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, Inc. Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede airworthiness directive (AD) 2014-16-
01 for MD Helicopters, Inc. (MDHI) Model MD900 helicopters. AD 2014-16-
01 requires an eddy current inspection of the main rotor upper hub 
assembly (upper hub) for a crack. Since we issued AD 2014-16-01, three 
additional upper hub cracks were reported. This proposed AD would 
require additional inspections and replacing the fillet seal. These 
proposed actions are intended to prevent an unsafe condition on these 
products.

DATES: We must receive comments on this proposed AD by June 2, 2017.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online instructions for sending your 
comments electronically.
     Fax: 202-493-2251.
     Mail: Send comments to the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.
     Hand Delivery: Deliver to the ``Mail'' address between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-
0270; 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 proposed AD, the economic evaluation, any comments 
received, and other information. The street address for the Docket 
Operations Office (telephone 800-647-5527) is in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.
    For service information identified in this proposed 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 http://www.mdhelicopters.com. You may review 
service information at the FAA, Office of the Regional Counsel, 
Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, Fort Worth, TX 
76177.

FOR FURTHER INFORMATION CONTACT: Eric Schrieber, Aviation Safety 
Engineer, Los Angeles Aircraft Certification Office, Transport Airplane 
Directorate, FAA, 3960 Paramount Blvd., Lakewood, California 90712; 
telephone (562) 627-5348; email eric.schrieber@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to participate in this rulemaking by submitting 
written comments, data, or views. We also invite comments relating to 
the economic, environmental, energy, or federalism impacts that might 
result from adopting the proposals in this document. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. To 
ensure the docket does not contain duplicate comments, commenters 
should send only one copy of written comments, or if comments are filed 
electronically, commenters should submit only one time.
    We will file in the docket all comments that we receive, as well as 
a report summarizing each substantive public contact with FAA personnel 
concerning this proposed rulemaking. Before acting on this proposal, we 
will consider all comments we receive on or before the closing date for 
comments. We will consider comments filed after the comment period has 
closed if it is possible to do so without incurring expense or delay. 
We may change this proposal in light of the comments we receive.

Discussion

    On July 24, 2014, we issued AD 2014-16-01, Amendment 39-17925 (79 
FR 45322, August 5, 2014), for MDHI Model MD900 helicopters, serial 
numbers 900-00008 through 900-00140, with an upper hub part number (P/
N) 900R2101006-105, -107, -109, or -111 installed. AD 2014-16-01 
requires, within 25 hours time-in-service (TIS), eddy current 
inspecting the upper hub for a crack and replacing the upper hub before 
further flight if there is a crack. AD 2014-16-01 was prompted by a 
report that four cracks were found at the blade attach holes on a high-
time upper hub. The actions in AD 2014-16-01 were intended to detect a 
crack on the upper hub, which if not corrected could result in failure 
of the upper hub and subsequent loss of control of the helicopter.

Actions Since AD 2014-16-01 Was Issued

    Since we issued AD 2014-16-01, we received reports of three 
additional cracks found in the MD900 fleet. These cracks were not 
discovered by the one-time eddy current inspection required by AD 2014-
16-01, but were found during regular maintenance of the upper hub. MDHI 
determined that in addition to the repetitive inspections of the upper 
hub annually and at 100 and 1,000 hours TIS in its maintenance manual, 
inspections should be accomplished and a fillet seal should be 
installed to prevent moisture in the interface of the bushing and the 
flex beam retention bolt hole. MDHI also determined that these 
inspections should be accomplished on all P/N 900R2101006-105, -107, -
109, and -111 upper hubs with 1,000 or more hours TIS, regardless of 
helicopter serial number.
    These proposed actions are intended to detect a crack on the upper 
hub, which if not corrected could result in failure of the upper hub 
and subsequent loss of control of the helicopter.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information

[[Page 16139]]

and determined the unsafe condition described previously is likely to 
exist or develop in other helicopters of the same type design.

Related Service Information Under 1 CFR Part 51

    MDHI has issued Service Bulletin SB900-125, dated February 19, 
2016, which describes procedures for repetitive visual and eddy current 
inspections of the upper hub upper and lower flexbeam bolthole areas 
and for applying a fillet seal on the interface of the bushing and the 
flex beam retention bolt hole.
    This service information is reasonably available because the 
interested parties have access to it through their normal course of 
business or by the means identified in the ADDRESSES section.

Proposed AD Requirements

    This proposed AD would require for MDHI MD900 helicopters with an 
upper hub P/N 900R2101006-105, -107, -109, and -111:
    Within 100 hours TIS and thereafter at intervals not exceeding 100 
hours TIS, using a 10X or higher magnifying glass, inspecting the 
fillet seal and the areas around the flexbeam boltholes for a crack;
    Within 12 months and thereafter at intervals not exceeding 12 
months, removing the paint, primer, and fillet seal around the flexbeam 
boltholes and, using a 10X or higher magnifying glass, inspecting the 
area for a crack;
    Within 12 months and thereafter at intervals not exceeding 12 
months, inspecting the lead leg shims and bushings for corrosion around 
the flexbeam boltholes, and if there is corrosion, removing the lead 
leg shim and inspecting for a crack;
    Within 1,000 hours TIS and thereafter at intervals not exceeding 
1,000 hours TIS, eddy-current inspecting the areas adjacent to the 
flexbeam boltholes for a crack;
    If during any inspection required by the proposed AD there is a 
crack, replacing the upper hub before further flight; and
    Finally, after each inspection required by the proposed AD, 
installing a fillet seal to the bushing and upper hub interface.

Differences Between This Proposed AD and the Service Information

    The service information applies to upper hubs with 1,000 or more 
hours TIS. This proposed AD would apply to all upper hubs regardless of 
hours TIS. The service information applies to upper hub P/N 
900R2101006-107 and -109; the proposed AD would also apply to upper hub 
P/N 900R2101006-105 and -111.

Costs of Compliance

    We estimate that this proposed AD would affect 23 helicopters of 
U.S. Registry.
    At an average labor rate of $85 per hour, we estimate that 
operators may incur the following costs in order to comply with this 
AD. Inspecting the fillet seal around the flexbeam boltholes (100 hour 
TIS inspection) would require about 1 work-hour, for a cost per 
helicopter of $85 and a cost of $1,955 for the fleet, per inspection 
cycle. Inspecting the flexbeam area and lead leg shims and bushings 
(annual inspection) would require about 2 work-hours, for a cost per 
helicopter of $170 and a cost of $3,910 for the fleet, per inspection 
cycle. Eddy current inspecting (1,000 hour TIS inspection) the upper 
hub would require about 2 work-hours, for a cost per helicopter of $170 
and a cost of $3,910 for the fleet.
    If required, replacing the upper hub would require about 11 work-
hours, and required parts would cost about $15,998, for a cost per 
helicopter of $16,933.
    If required, replacing a missing or damaged fillet seal would 
require about .5 work-hour, and required parts cost would be minimal, 
for a cost per helicopter of $43.

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

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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, I certify this proposed 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);
    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 proposed 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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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 removing Airworthiness Directive (AD) 
2014-16-01, Amendment 39-17925(79 FR 45322, August 5, 2014), and adding 
the following new AD:

MD Helicopters, Inc. (MDHI): Docket No. FAA-2017-0270; Directorate 
Identifier 2016-SW-032-AD.

(a) Applicability

    This AD applies to Model MD900 helicopters with main rotor upper 
hub assembly (upper hub) part number 900R2101006-105, -107, -109, or 
-111 installed, certificated in any category.

(b) Unsafe Condition

    This AD defines the unsafe condition as a cracked upper hub. 
This condition could result in failure of the upper hub and 
subsequent loss of control of the helicopter.

(c) Affected ADs

    This AD supersedes AD 2014-16-01, Amendment 39-17925 (79 FR 
45322, August 5, 2014).

[[Page 16140]]

(d) Comments Due Date

    We must receive comments by June 2, 2017.

(e) 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.

(f) Required Actions

    (1) Within 100 hours time-in-service (TIS), and thereafter at 
intervals not to exceed 100 hours TIS:
    (i) Inspect the fillet seal around each flexbeam bolthole to 
determine whether it adheres properly to the hub or bushing or is 
missing. Indications of an improperly adhered seal include lifting, 
bubbling, peeling away, drying out, or cracking. If the fillet seal 
is not properly adhered or is missing, before further flight, 
replace the fillet seal with sealant C232 or equivalent by following 
the Accomplishment Instructions, paragraphs 2.D.(2) through 2.D.(5) 
and Figure 1, of MD Helicopters Service Bulletin SB900-125, dated 
February 19, 2016 (SB900-125).
    (ii) Using a light and a 10X or higher power magnifying glass, 
inspect the area outside of the fillet seal around each flexbeam 
bolthole on the top of the upper hub assembly for a crack. If there 
is a crack, before further flight, replace the upper hub assembly.
    (2) Within 12 months, and thereafter at intervals not to exceed 
12 months:
    (i) Remove the paint and primer from the area around each 
flexbeam bolthole on top of the upper hub. Remove the fillet seal 
from the mating surface of each bushing and the top of the upper 
hub.
    (ii) Using a light and a 10X or higher power magnifying glass, 
inspect the area around each flexbeam bolthole for a crack. If there 
is a crack, before further flight, replace the upper hub assembly.
    (iii) Inspect each lead leg shim and bushing for corrosion 
around the flexbeam boltholes on the bottom of the upper hub in the 
flexbeam pockets. If there is corrosion, before further flight:
    (A) Remove the lead leg shim from the flexbeam pocket and clean 
the area adjacent to the flexbeam bolthole to remove any corrosion 
within maximum repair damage limits. If the corrosion exceeds 
maximum repair damage limits, replace the upper hub assembly.
    (B) Using a light and a 10X or higher power magnifying glass, 
inspect the area around the flexbeam bolthole for a crack. If there 
is a crack, before further flight, replace the upper hub assembly.
    (iv) Replace the fillet seal as described in paragraph (f)(1)(i) 
of this AD.
    (3) Within 1,000 hours TIS, and thereafter at intervals not to 
exceed 1,000 hours TIS:
    (i) Eddy current inspect the areas adjacent to each flexbeam 
bolthole, top and bottom, for a crack. This eddy current inspection 
must be performed by a Level II or higher technician with the 
American Society for Nondestructive Testing ASNT-TC-1A, European 
Committee for Standardization CEN EN 4179, Military Standard MIL-
STD-410, National Aerospace Standard NAS410, or equivalent 
certification who has performed an eddy current inspection within 
the last 12 months. If there is a crack, before further flight, 
replace the upper hub assembly.
    (ii) Replace the fillet seal as described in paragraph (f)(1)(i) 
of this AD.

(g) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles Aircraft Certification Office, FAA, 
may approve AMOCs for this AD. Send your proposal to: Eric 
Schrieber, Aviation Safety Engineer, Los Angeles Aircraft 
Certification Office, Transport Airplane Directorate, FAA, 3960 
Paramount Blvd., Lakewood, California 90712; telephone (562) 627-
5348; 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, 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.

(h) Subject

    Joint Aircraft Service Component (JASC) Code: 6220 Main Rotor 
Head.

    Issued in Fort Worth, Texas, on March 27, 2017.
Scott A. Horn,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2017-06460 Filed 3-31-17; 8:45 am]
BILLING CODE 4910-13-P


