83 FR 48366 - Airworthiness Directives; Airbus Helicopters

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 83, Issue 186 (September 25, 2018)

We are adopting a new airworthiness directive (AD) for Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters. This AD requires measuring a vibration level in the tail rotor (T/R) drive. This AD was prompted by reports of bearing degradation. The actions of this AD are intended to prevent an unsafe condition on these helicopters.

[Federal Register Volume 83, Number 186 (Tuesday, September 25, 2018)]
[Rules and Regulations]
[Pages 48366-48368]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2018-20487]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0438; Product Identifier 2017-SW-062-AD; Amendment 
39-19410; AD 2018-19-10]
RIN 2120-AA64


Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for Airbus 
Helicopters Model AS355E, AS355F, AS355F1, AS355F2, and AS355N 
helicopters. This AD requires measuring a vibration level in the tail 
rotor (T/R) drive. This AD was prompted by reports of bearing 
degradation. The actions of this AD are intended to prevent an unsafe 
condition on these helicopters.

DATES: This AD is effective October 30, 2018.

ADDRESSES: For service information identified in this final rule, 
contact Airbus Helicopters, 2701 N Forum Drive, Grand Prairie, TX 
75052; telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; 
or at http://www.helicopters.airbus.com/website/en/ref/Technical-Support_73.html. 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.

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-2018-
0438; or in person at Docket Operations

[[Page 48367]]

between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the European Aviation Safety 
Agency (EASA) AD, the economic evaluation, any comments received, and 
other information. The street address for Docket Operations (phone: 
800-647-5527) 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: Rao Edupuganti, Aviation Safety 
Engineer, Regulations and Policy Section, Rotorcraft Standards Branch, 
FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-
5110; email [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    On May 17, 2018, at 83 FR 22886, the Federal Register published our 
notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR 
part 39 by adding an AD that would apply to Airbus Helicopters Model 
AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters. The NPRM 
proposed to require measuring the T/R drive vibration level without 
balancing, cleaning the fan, and repeating the vibration level 
measurement. If the difference between the two amplitude values is 
greater than 0.75 inch per second (ips), the NPRM proposed to require 
replacing each T/R fan bearing. The proposed requirements were intended 
to prevent degradation of the main gearbox (MGB) oil cooler fan bearing 
(bearing), which could result in loss of MGB and engine oil cooling 
function, loss of the rear transmission, and subsequent loss of control 
of the helicopter.
    The NPRM was prompted by AD No. 2017-0159, dated August 25, 2017, 
issued by EASA, which is the Technical Agent for the Member States of 
the European Union, to correct an unsafe condition for Airbus 
Helicopters Model AS355E, AS355F, AS355F1, AS355F2, and AS355N 
helicopters. EASA advises of two occurrences on Model AS355 military 
helicopters in which the MGB bearing installed on the T/R drive shaft 
experienced significant degradation. EASA states that while 
investigation has not determined the cause of the failures, this 
condition may also occur on other Model AS355 helicopters due to design 
commonality. According to EASA, this condition, if not detected and 
corrected, could result in loss of MGB and engine oil cooling function, 
loss of the rear transmission, and subsequent loss of control of the 
helicopter. To address this unsafe condition and as an interim measure, 
the EASA AD requires two vibration level measurements of the forward 
portion of the tail rotor drive line, one before and one after cleaning 
the MGB oil cooler fan, and replacing the bearings if excessive level 
or level trends are detected. The EASA AD also specifies that after the 
effective date of the AD, only those MGB oil cooler fan assembly 
bearings that are new or that have passed the vibration level 
measurements may be installed.

Comments

    We gave the public the opportunity to participate in developing 
this AD, but we did not receive any comments on the NPRM.

FAA's Determination

    These helicopters have been approved by the aviation authority of 
France and are approved for operation in the United States. Pursuant to 
our bilateral agreement with France, EASA, its technical 
representative, has notified us of the unsafe condition described in 
the EASA AD. We are issuing this AD because we evaluated all 
information provided by EASA and determined the unsafe condition exists 
and is likely to exist or develop on other helicopters of the same type 
design and that air safety and the public interest require adopting the 
AD requirements as proposed.

Interim Action

    We consider this AD to be an interim action. The manufacturer is 
currently developing a terminating action for the unsafe condition 
described in this AD. If a terminating action is identified, we may 
consider further rulemaking then.

Related Service Information

    Airbus Helicopters has issued Alert Service Bulletin No. AS355-
05.00.77, Revision 0, dated July 3, 2017, which contains procedures for 
checking the condition of the fan assembly bearings by measuring the 
vibration levels of the first section of the T/R drive.

Costs of Compliance

    We estimate that this AD affects 104 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, measuring the 
vibration levels requires about 5 work-hours, for a cost of $425 per 
helicopter and $44,200 for the U.S. fleet. If required, replacing both 
fan assembly bearings requires about 8 work-hours, and required parts 
cost $1,064, for a cost of $1,744 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.
    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 helicopters 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:


[[Page 48368]]


    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):

2018-19-10 Airbus Helicopters: Amendment 39-19410; Docket No. FAA-
2018-0438; Product Identifier 2017-SW-062-AD.

(a) Applicability

    This AD applies to Airbus Helicopters Model AS355E, AS355F, 
AS355F1, AS355F2, and AS355N helicopters, certificated in any 
category.

(b) Unsafe Condition

    This AD defines the unsafe condition as degradation of a main 
gearbox (MGB) oil cooler fan assembly bearing. This condition could 
result in loss of MGB and engine oil cooling function, loss of the 
rear transmission, and subsequent loss of control of the helicopter.

(c) Effective Date

    This AD becomes effective October 30, 2018.

(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) Within 165 hours time-in-service (TIS):
    (i) Measure the tail rotor (T/R) drive vibration level without 
balancing the T/R drive, and record the amplitude value.
    (ii) Clean the oil cooler fan.
    (iii) Measure the T/R drive vibration level without balancing 
the T/R drive, and record the amplitude value.
    (iv) Calculate the difference between the two amplitude values. 
If the difference is greater than 0.75 inch per second (ips), before 
further flight, replace each oil cooler fan assembly bearing.
    (2) After the effective date of this AD, do not install an oil 
cooler fan assembly bearing with more than 0 hours TIS unless the 
requirements of this AD have been accomplished.

(f) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Safety Management Section, Rotorcraft Standards 
Branch, FAA, may approve AMOCs for this AD. Send your proposal to: 
Rao Edupuganti, Aviation Safety Engineer, Regulations and Policy 
Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., 
Fort Worth, TX 76177; telephone (817) 222-5110; 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.

(g) Additional Information

    (1) Airbus Helicopters Alert Service Bulletin No. AS355-
05.00.77, Revision 0, dated July 3, 2017, which is not incorporated 
by reference, contains additional information about the subject of 
this AD. For service information identified in this AD, contact 
Airbus Helicopters, 2701 N Forum Drive, Grand Prairie, TX 75052; 
telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or 
at http://www.helicopters.airbus.com/website/en/ref/Technical-Support_73.html. 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.
    (2) The subject of this AD is addressed in European Aviation 
Safety Agency (EASA) AD No. 2017-0159, dated August 25, 2017. You 
may view the EASA AD on the internet at http://www.regulations.gov 
in Docket No. FAA-2018-0438.

(h) Subject

    Joint Aircraft Service Component (JASC) Code: 6510, Tail Rotor 
Driveshaft.

    Issued in Fort Worth, Texas, on September 12, 2018.
Scott A. Horn,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2018-20487 Filed 9-24-18; 8:45 am]
 BILLING CODE 4910-13-P