DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2014-0395; Directorate Identifier 2014-SW-016-AD;
Amendment 39-17876; AD 2014-06-51]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters Deutschland GmbH
(Airbus Helicopters) (Type Certificate Previously Held by Eurocopter
Deutschland GmbH) Helicopters

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: We are publishing a new airworthiness directive (AD) for
Airbus Helicopters Model MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1,
and MBB-BK 117 C-2 helicopters with a certain Metro Aviation, Inc.
(Metro), vapor-cycle air conditioning kit pulley (pulley) installed,
which was sent previously to all known U.S. owners and operators of
these helicopters. This AD supersedes AD 2013-12-06, which required
inspecting the pulley for looseness and properly installed lockwire and
re-installing the pulley. Since we issued AD 2013-12-06, we received a
report of a possible design and manufacturing deficiency in some
pulleys wherein they did not have sufficient thread depth, allowing the
pulley to detach from the rotor brake disc. This AD requires inspecting
each pulley attaching bolt hole to determine if there is sufficient
depth of the threads and either removing the pulley if the depth is
insufficient or installing dual locking tabs under each pulley
attaching bolt if the depth is sufficient. These actions are intended
to prevent the pulley from detaching, resulting in damage to the tail
rotor (T/R) driveshaft, and subsequent loss of control of the helicopter.

DATES: This AD becomes effective July 30, 2014 to all persons except
those persons to whom it was made immediately effective by Emergency AD
(EAD) 2014-06-51, issued on March 24, 2014, which contains the
requirements of this AD.

The Director of the Federal Register approved the incorporation by
reference of a certain document listed in this AD as of July 30, 2014.

We must receive comments on this AD by September 15, 2014.

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
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
incorporated by reference service information, 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 AD, contact Metro
Aviation, Inc., 1214 Hawn Ave, Shreveport, LA 71107; phone: (318) 222-5529; Web site:
metroproductsupport.com. You may review the referenced service
information at the FAA, Office of the Regional Counsel, Southwest
Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Martin Crane, Aviation Safety
Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA,
2601 Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222-5170;
email 7-AVS-ASW-170@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

This AD is a final rule that involves requirements affecting flight
safety, and we did not provide you with notice and an opportunity to
provide your comments prior to it becoming effective. However, 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 resulted
from adopting this AD. The most helpful comments reference a specific
portion of the AD, 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 them 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 rulemaking during the
comment period. We will consider all the comments we receive and may
conduct additional rulemaking based on those comments.

Discussion

On June 13, 2013, we issued AD 2013-12-06, Amendment 39-17484 (78
FR 40956, July 9, 2013) (AD 2013-12-06), for Eurocopter Deutschland
GmbH (now Airbus Helicopters) Model MBB-BK 117 A-3, MBB-BK 117 A-4,
MBB-BK 117 B-1, and MBB-BK 117 C-2 helicopters with a Metro vapor-cycle
air conditioning kit installed in accordance with Supplemental Type
Certificate No. SH3880SW. AD 2013-12-06 required repetitively
inspecting the air conditioning drive pulley for looseness and properly
installed lockwire, and also required reinstalling the pulley. AD 2013-
12-06 resulted from two reports of the pulley detaching from the rotor
brake disk on the T/R driveshaft. We issued AD 2013-12-06 to prevent
separation of the pulley, damage to the T/R driveshaft, and subsequent
loss of control of the helicopter.

Actions Since AD 2013-12-06 Was Issued

After we issued AD 2013-12-06, Metro developed a procedure to
install a tabbed washer underneath the bolt heads securing the pulley
to the rotor disc. This procedure was intended to provide a secondary
locking feature to the bolts, and to relieve the requirement for
repetitive inspections of the safety wire which secures the bolts. On
December 20, 2013, Metro requested and we approved this procedure as a
global Alternative Method of Compliance (AMOC) for AD 2013-12-06 in
lieu of performing the repetitive inspections required by paragraph (e)
of that AD.

On March 10, 2014, we received a report that an attaching bolt
would not seat on the mating surface of the pulley. Compliance with the
AMOC revealed a possible design deficiency and a manufacturing defect
in some pulleys. Metro has determined that the pulley, along with two
additional pulleys from other helicopters, did not have sufficient
thread depth. This condition may allow the attaching bolts to come
loose, resulting in the pulley detaching from the rotor brake disc,
subsequent damage to the T/R driveshaft, and loss of control of the
helicopter.

On March 24, 2014, we issued EAD 2014-06-51, which superseded AD
2013-12-06, for those to whom it was made immediately effective. EAD
2014-06-51 requires inspecting the pulley to determine if there is
sufficient depth of the threads and removing the pulley if there is not
sufficient depth. EAD 2014-06-51 also requires installing a dual
locking tab on each pulley attaching bolt and reporting the inspection
findings to the FAA. Finally, EAD 2014-06-51 revises the applicability
to helicopters with a pulley, P/N 30001, installed rather than with the
air conditioning kit installed because this pulley has been determined
to be the unsafe condition. EAD 2014-06-51 was sent previously to all
known U.S. owners and operators of these helicopters. The actions in
EAD 2014-06-51 are intended to prevent the pulley detaching from the
rotor brake disc, subsequent damage to the T/R driveshaft, and loss of
control of the helicopter.

FAA's Determination

We are issuing this AD because we evaluated all the relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of these same type designs.

Related Service Information

We reviewed Metro Alert Service Bulletin (ASB) No. MA145-21B-003,
Revision B, dated December 20, 2013 (ASB MA145-21B-003), which
describes procedures for installing a dual-locking tab on the air
conditioning drive pulley attachment bolts.
Since we issued EAD 2014-06-51, Metro released ASB No. MA145-21-
004, Revision IR, dated March 24, 2014, which describes procedures for
inspecting the air conditioning drive pulley thread depth. This AD
continues to reference ASB MA145-21B-003.

AD Requirements

This AD requires, within 5 hours time-in-service, inspecting each
pulley attaching bolt hole to determine if there is sufficient depth of
the threads. If the depth is less than 0.61 inch, this AD requires
removing the pulley. This AD also requires installing dual locking tabs
under each pulley attaching bolt by following the Accomplishment
Instructions, paragraphs 3.E. through 3.G., of ASB MA145-21B-003. This
AD also requires submitting a report of the inspection findings to the
FAA.

Differences Between This AD and the Service Information

This AD requires determining the depth of the threaded portion of
the pulley attaching bolt holes; the service information does not.

Costs of Compliance

We estimate that this AD will affect 75 helicopters of U.S.
Registry. We estimate that operators may incur the following costs in
order to comply with this AD. At an average labor rate of $85 per work-
hour, inspecting the pulley bolt holes, and installing the tabbed
washers will require 6 work hours, and required parts will cost $100,
for a cost per helicopter of $610 and a total cost of $45,750 for the
fleet.

Reviewing instructions, collecting and reviewing information, and
submitting a report to the FAA will require 0.5 work-hour, for a cost
per helicopter of $43 and a cost of $3,225 for the fleet.

If necessary, replacing a pulley will require about 2 work-hours,
and required parts would cost $800, for a total cost per helicopter of
$970.

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a current valid OMB control number. The control
number for the collection of information required by this AD is 2120-
0056. The paperwork cost associated with this AD has been detailed in
the Costs of Compliance section of this document and includes time for
reviewing instructions, as well as completing and reviewing the
collection of information. Therefore, all reporting required by this AD
is mandatory. Comments concerning the accuracy of this burden and
suggestions for reducing the burden should be directed to the FAA at
800 Independence Ave. SW., Washington, DC 20591. ATTN: Information
Collection Clearance Officer, AES-200.

FAA's Justification and Determination of the Effective Date

Providing an opportunity for public comments before adopting these
AD requirements would delay implementing the safety actions needed to
correct this known unsafe condition. Therefore, we found and continue
to find that the risk to the flying public justifies waiving notice and
comment prior to adopting this rule because the required corrective
actions must be done within 5 hours time-in-service, a very short time
period based on the average flight-hour utilization rate of these
helicopters.

Since it was found that immediate corrective action was required,
notice and opportunity for prior public comment before issuing this AD
were impracticable and contrary to the public interest and that good
cause existed to make the AD effective immediately by EAD 2014-06-51,
issued on March 24, 2014, to all known U.S. owners and operators of
these helicopters. These conditions still exist and the AD is hereby
published in the Federal Register as an amendment to section 39.13 of
the Federal Aviation Regulations (14 CFR 39.13) to make it effective to
all persons.

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 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, 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

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]

2. The FAA amends Sec. 39.13 by removing Airworthiness Directive (AD)
2013-12-06, Amendment 39-17484 (78 FR 40956, July 9, 2013), and adding
the following new AD: