82 FR 18690 - Airworthiness Directives; Airbus Helicopters

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 76 (April 21, 2017)

We are superseding Emergency Airworthiness Directive (Emergency AD) 2015-24-51 for Airbus Helicopters Model EC120B. Emergency AD 2015-24-51 required inspections of the air conditioning system. This supersedure revises the applicability, some of the terminology, and the inspection requirements. This AD was prompted by a report of an abnormal noise during flight of a Model EC120B helicopter that resulted in a precautionary landing. We are issuing this AD to prevent an unsafe condition on these products.

[Federal Register Volume 82, Number 76 (Friday, April 21, 2017)]
[Rules and Regulations]
[Pages 18690-18694]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-07777]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-4674; Directorate Identifier 2016-SW-001-AD; 
Amendment 39-18835; AD 2017-06-11]
RIN 2120-AA64


Airworthiness Directives; Airbus Helicopters

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

ACTION: Final rule; request for comments.

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SUMMARY: We are superseding Emergency Airworthiness Directive 
(Emergency AD) 2015-24-51 for Airbus Helicopters Model EC120B. 
Emergency AD 2015-24-51 required inspections of the air conditioning 
system. This supersedure revises the applicability, some of the 
terminology, and the

[[Page 18691]]

inspection requirements. This AD was prompted by a report of an 
abnormal noise during flight of a Model EC120B helicopter that resulted 
in a precautionary landing. We are issuing this AD to prevent an unsafe 
condition on these products.

DATES: This AD becomes effective May 8, 2017.
    We must receive comments on this AD by June 20, 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-2016-
4674; 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 Supplemental Type Certificate (STC), 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 final rule, contact Air 
Comm Corporation, 1575 West 124th Avenue, Westminster, CO 80234, 
telephone: (303) 440-4075 (during business hours) or (720) 233-8330 
(after hours), email [email protected], Web site http://www.aircommcorp.com/contact. You may review the referenced 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: Richard R. Thomas, Aviation Safety 
Engineer, Denver Aircraft Certification Office, FAA, Technical 
Operations Center, 26805 East 68th Avenue, Room 214, Denver, CO 80249; 
telephone (303) 342-1085; fax (303) 342-1088; email 
[email protected].

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 November 27, 2015, we issued Emergency AD 2015-24-51, which was 
made immediately effective to all known U.S. owners and operators of 
Airbus Helicopters Model EC120B helicopters. Emergency AD 2015-24-51 
applied to Model EC120B helicopters with an Air Comm Corporation (Air 
Comm) air conditioning system installed in accordance with STC No. 
SR00491DE. Emergency AD 2015-24-51 required, before further flight and 
at intervals not to exceed 25 hours time-in-service (TIS), manually 
inspecting the air conditioner compressor drive pulley (pulley) for 
movement (play) between the pulley and the tail rotor output wheel 
(wheel). If there was any movement, Emergency AD 2015-24-51 required 
replacing the pulley and the wheel before further flight. If no play 
existed, Emergency AD 2015-24-51 required an additional inspection for 
wear and, if needed, replacing the pulley and the wheel. Emergency AD 
2015-24-51 also required reporting information to the FAA to enable us 
to obtain better insight into the cause of the unsafe condition.
    Emergency AD 2015-24-51was prompted by a report that the operator 
of an Airbus Helicopters Model EC120B helicopter heard an abnormal 
noise during flight that gradually became more pronounced, resulting in 
a precautionary landing. While applying power to land, the helicopter 
yawed left. Application of the right pedal did not correct the 
rotation, requiring the pilot to perform a hovering auto rotation. A 
preliminary investigation showed that the pulley and wheel mating 
splines had worn away, allowing the pulley to rotate freely on the 
wheel. Failure of the pulley and wheel during flight may result in the 
loss of tail rotor drive and subsequent loss of directional control.

Actions Since AD 2014-24-51 Was Issued

    After Emergency AD 2015-24-51 was issued, we received a comment 
from an operator requesting that we clarify the applicability of the 
AD. The commenter notes that there are two different configurations for 
the Air Comm conditioning system, the earlier of which has the output 
flange that is terminating action in the AD already installed. However, 
the applicability of Emergency AD 2015-24-51 does not distinguish 
between the two configurations. Pictures from another operator we 
received with an inspection report showed this earlier configuration 
where the compressor is driven by a pulley mounted forward of the rotor 
brake.
    We agree with the request to clarify the applicability. Pulleys 
installed forward of the rotor brake are not part of the tail rotor 
drive train and their failure would not result in a loss of directional 
control. We have revised this AD to apply only to those helicopters 
with an Air Comm air conditioning kit installed in accordance with STC 
No. SR00491DE where the compressor is driven by a pulley installed aft 
of the rotor brake. Helicopters that have an Air Comm air conditioning 
kit installed in accordance with STC No. SR00491DE where the compressor 
is driven by a pulley forward of the rotor brake are excluded from this 
AD's requirements.
    We are replacing the term ``tail rotor output pinion'' used in 
Emergency AD 2015-24-51 with ``tail rotor output wheel,'' because it is 
the more commonly known term for this part.
    We also received a comment from an operator stating that if play 
between the pulley and the wheel is found during the inspection, and if 
the Air Comm pulley is replaced with an Airbus output flange, the AD 
should not require that the wheel be replaced if it passes the damage 
and wear criteria in the Airbus Helicopters maintenance manual. We 
agree that in the absence of wear, regardless of any play, the wheel 
should not have to be replaced. We are revising the required actions in 
this AD to remove the inspection for play and instead require an 
inspection of the

[[Page 18692]]

wheel for damage and wear, using criteria consistent with that in the 
Airbus Helicopters maintenance manual.
    We also obtained additional information from Air Comm about the 
effect of the terminating action in Emergency AD 2015-24-51 and whether 
it is necessary to deactivate the airconditioning system. As a result, 
we are removing from the terminating action the requirement to fully or 
partially deactivate the air conditioning system. Replacing the Air 
Comm pulley with Airbus Helicopters output flange part number 
C632A2158201 partially deactivates the system. With the Air Comm pulley 
replaced, the system is sufficiently deactivated. Cooling will no 
longer be available, but the evaporator blowers will remain operable to 
circulate air. Neither the air conditioning system nor the helicopter 
will be damaged by removing the compressor drive belt and leaving the 
circuit breakers engaged.
    We also have learned that this AD affects five helicopters of U.S. 
registry, and not only the two helicopters noted in Emergency AD 2015-
24-51.

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 this same type design and that air safety and the public 
interest require adopting the AD requirements as proposed.

Related Service Information

    We reviewed Air Comm Service Bulletin SB-EC120-111815, Revision A, 
dated November 20, 2015. Air Comm reports that the pulley, mounted to 
the Thomas coupling just aft of the main rotor brake caliper, is an 
integral piece of the power transmission components for the tail rotor. 
A field report indicated that the spline joint on the pulley can wear 
beyond its capability to ensure power transmission to the tail rotor 
shaft. Given that the installation is flight critical, the Air Comm 
service bulletin specifies an inspection of the pulley-output wheel 
interface. If excessive play or wear is found, the aircraft must be 
made inoperable until unairworthy parts are replaced.

AD Requirements

    This AD requires, before further flight and at intervals not to 
exceed 25 hours TIS, removing the pulley and visually inspecting the 
pulley splines for wear and inspecting the exposed portion of the wheel 
splines for cracks, scoring, metal pick-up, and measuring for wear. If 
any of the splines on the pulley are not straight, contain any 
inconsistent cross-sections end-to-end, or contain any localized 
material deformation or any material loss, this AD requires replacing 
the pulley before further flight. If there is cracking, any scoring or 
metal pick-up, or if a measurement shows wear, this AD requires 
replacing the wheel before further flight.
    This AD also requires reporting certain information to the FAA 
within 10 days.
    Replacing the Air Comm pulley with Airbus Helicopters output flange 
part number C632A2158201 constitutes terminating action for this AD.

Differences Between This AD and the Service Information

    The service information specifies recurring inspections after 100 
flight hours, while this AD requires recurring inspections at intervals 
not to exceed 25 hours TIS. The service information requires inspecting 
the pulley and drive shaft (wheel) splines for excessive wear or 
chatter and replacing the pulley and wheel if there is any play. This 
AD requires replacing the pulley if any splines are not straight, have 
inconsistent cross-sections, or contain material deformation or loss. 
This AD requires replacing the wheel if cracking, scoring, or metal 
pick-up are found, or measurement of the splines indicates excessive 
wear. The service information requests that information be submitted to 
Air Comm, while this AD requires the inspection results be reported to 
the FAA.

Costs of Compliance

    We estimate that this AD will affect 5 helicopters of U.S. Registry 
and that labor costs average $85 a work-hour. Based on these estimates 
we expect that inspecting the pulley and wheel will take about 7.5 
work-hours for a cost of $638 per helicopter and $3,190 for the U.S. 
fleet per inspection cycle. Replacing an Air Comm pulley will cost 
$2,380 for parts and 0.5 additional work-hour for a cost of $2,423 per 
helicopter. Replacing an Airbus wheel will cost $19,231 for parts and 
10 additional work-hours for a cost of $20,081 per helicopter. The 
optional terminating action of installing an Airbus output flange will 
cost $2,327 for parts and 0.5 additional work-hour for a cost of $2,370 
per helicopter. Reporting the required inspection information to the 
FAA will take about 0.5 work-hour for a cost of about $43 per 
helicopter and $215 for the U.S. fleet.

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 prior to adopting 
these AD requirements would delay implementing the safety actions 
needed to correct this known unsafe condition. Therefore, we find that 
the risk to the flying public justifies waiving notice and comment 
prior to the adoption of this rule because the required corrective 
actions must be accomplished before further flight.
    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we determined that notice and opportunity for 
prior public comment before issuing this AD are impracticable and 
contrary to the public interest and that good cause exists to make this 
AD effective in less than 30 days.

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

[[Page 18693]]

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

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):

2017-06-11 Airbus Helicopters: Amendment 39-18835; Docket No. FAA-
2016-4674; Directorate Identifier 2016-SW-001-AD.

(a) Applicability

    This AD applies to Airbus Helicopters Model EC120B helicopters 
with an Air Comm Corporation (Air Comm) air conditioning kit 
installed in accordance with supplemental type certificate (STC) No. 
SR00491DE, where the compressor is driven by a pulley installed aft 
of the rotor brake, certificated in any category.

(b) Unsafe Condition

    This AD defines the unsafe condition as failure of an air 
conditioner compressor drive pulley (pulley) or tail rotor output 
wheel (wheel), leading to loss of tail rotor drive and helicopter 
control.

(c) Affected ADs

    This AD supersedes Emergency AD 2015-24-51, Directorate 
Identifier 2015-SW-086-AD, dated November 27, 2015.

(d) Effective Date

    This AD becomes effective May 8, 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) Before further flight, and at intervals not to exceed 25 
hours time-in-service, disassemble the tail rotor drive system and 
remove the pulley.
    (i) Visually inspect the pulley splines for wear. If any splines 
are not straight, contain any inconsistent cross-sections end-to-
end, or contain any localized material deformation or any material 
loss, replace the pulley before further flight.
    Note 1 to paragraph (f)(1)(i) of this AD: End-to-end (fore-and-
aft) movement witness marks and polishing are acceptable as the 
pulley is allowed to slip fore and aft on the wheel per its intended 
function.
    (ii) Inspect the exposed portion of each wheel spline for 
cracking, scoring, metal pick-up, and wear by using Figure 1 to 
paragraph (f)(1)(ii) of this AD. To inspect for wear, position two 3 
mm (0.118 inch) rods in all diametrically opposed splines and 
measure to determine whether there is a minimum of 37.3 mm (1.47 
inches) across the outside diameter of the rods. If there is any 
cracking, scoring or metal pick-up, or if a measurement is less than 
37.3 mm, replace the wheel.
[GRAPHIC] [TIFF OMITTED] TR21AP17.000

    (2) Within 10 days after completing the initial inspection, 
report the information requested in Appendix 1 to this AD by mail to 
the Denver Aircraft Certification Office, FAA, Technical Operations 
Center, 26805 East 68th Avenue, Room 214, Denver, CO 80249, attn. 
Richard R. Thomas; by fax to (303) 342-1088; or by email to 
[email protected].
    (3) Replacing the Air Comm pulley with Airbus Helicopters output 
flange part number C632A2158201 constitutes terminating action for 
this AD.

(g) Special Flight Permits

    Special flight permits are prohibited.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Denver Aircraft Certification Office, FAA, may 
approve

[[Page 18694]]

AMOCs for this AD. Send your proposal to: Richard R. Thomas, 
Aerospace Engineer, Denver Aircraft Certification Office, FAA, 
Technical Operations Center, 26805 East 68th Avenue, Room 214, 
Denver, CO 80249; fax (303) 342-1088; email 
[email protected].
    (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.

(i) Additional Information

    (i) Air Comm Service Bulletin No. SB-EC120-111815, Revision A, 
dated November 20, 2015, which is not incorporated by reference, 
contains additional information about the subject of this AD. For 
service information identified in this AD, contact: Air Comm 
Corporation, 1575 West 124th Avenue, Westminster, CO 80234, 
telephone: (303) 440-4075 (during business hours) or (720) 233-8330 
(after hours); email: [email protected], Web site: http://www.aircommcorp.com/contact.
    (ii) You may view a copy of Supplemental Type Certificate No. 
SR00491DE, reissued on November 24, 2014, on the Internet at http://www.regulations.gov by searching for and locating it in Docket No. 
FAA-2016-4674.
    (iii) You may review a copy of the service information at the 
FAA, Office of the Regional Counsel, Southwest Region, 10101 
Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177.

(j) Subject

    Joint Aircraft Service Component (JASC) Code: 6500, Tail Rotor 
Drive System.

    Issued in Fort Worth, Texas, on February 1, 2017.
Scott A. Horn,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

Appendix 1 to AD 2017-06-11

    Please report the following to the Denver Aircraft Certification 
Office, FAA, Technical Operations Center, by mail to 26805 East 68th 
Avenue, Room 214, Denver, CO 80249, attn. Richard R. Thomas; by fax 
to (303) 342-1088; or by email to [email protected]:
    (1) Condition of the splined joint. Document any damage found 
with photographs.
    (2) Flight hours since the air-conditioning kit was installed.
    (3) Aircraft serial number.
    (4) Pulley serial number (etched on the pulley's face).
    (5) Output wheel serial number from main gearbox, MAIN MODULE 
hard card.
    (6) Primary operating location of the aircraft.
    (7) Approximate average percentage of time the air conditioner 
is used.
    (8) Operator and maintenance facility contact information.
    (9) If parts are replaced, will air conditioning system remain 
fully or partially operable?


[FR Doc. 2017-07777 Filed 4-20-17; 8:45 am]
 BILLING CODE 4910-13-P