Document ID: FAA-2021-0460-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Airbus Helicopters
Posted Date: 2021-06-11T04:00Z

[Federal Register Volume 86, Number 111 (Friday, June 11, 2021)]
[Proposed Rules]
[Pages 31194-31196]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-12226]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0460; Project Identifier MCAI-2020-01620-R]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Airbus Helicopters Model AS355E, AS355F, AS355F1, and 
AS355F2 helicopters. This proposed AD was prompted by multiple fatigue 
cracks in power turbine (PT) 3rd stage wheels. This proposed AD would 
require revising the existing Rotorcraft Flight Manual (RFM) for your 
helicopter and installing a placard. The FAA is proposing this AD to 
address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by July 26, 
2021.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays.
    For Airbus Helicopters service information identified in this NPRM, 
contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 
75052; telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; 
or at https://www.airbus.com/helicopters/services/technical-support.html. For Rolls-Royce service information identified in this 
NPRM, contact Rolls-Royce plc, Corporate Communications, P.O. Box 31, 
Derby, DE24 8BJ, United Kingdom; phone: +44 (0)1332 242424; fax: +44 
(0)1332 249936; or at https://www.rolls-royce.com/contact-us.aspx. You 
may view 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 at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0460; 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 NPRM, the European 
Union Aviation Safety Agency (EASA) AD, any comments received, and 
other information. The street address for Docket Operations is listed 
above.

FOR FURTHER INFORMATION CONTACT: Michael Hughlett, Aerospace Engineer, 
General Aviation & Rotorcraft Section, International Validation Branch, 
FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-
5110; email michael.hughlett@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2021-0460; Project Identifier 
MCAI-2020-01620-R'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
this proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to 
Michael Hughlett, Aerospace Engineer, General Aviation & Rotorcraft 
Section, International Validation Branch, FAA, 10101 Hillwood Pkwy., 
Fort Worth, TX 76177; telephone (817) 222-5110; email 
michael.hughlett@faa.gov. Any commentary that the FAA receives which is 
not specifically designated as CBI will be placed in the public docket 
for this rulemaking.

Background

    EASA, which is the Technical Agent for the Member States of the 
European Union, has issued EASA AD 2020-0266, dated December 8, 2020 
(EASA AD 2020-0266), to correct an unsafe condition for Airbus 
Helicopters (AH), formerly Eurocopter, Eurocopter France, Aerospatiale 
Model AS 355 E, AS 355 F, AS 355 F1, and AS 355 F2 helicopters, all 
serial numbers, if equipped with Rolls-Royce Corporation (formerly 
Allison) (RRC) engine Model 250-C20F. EASA advises of multiple fatigue 
cracks in PT 3rd stage wheels. Investigation has revealed that crack 
initiation at the hub trailing edge could occur in low-cycle fatigue 
and progress in high-cycle fatigue up to separation of the blade. 
According to EASA, RRC has determined that detrimental vibrations could 
occur within a particular range of turbine speeds, below the normal 
operating range of this helicopter, which are a potential contributing 
factor to these failures. This condition, if not addressed, could 
result in fatigue failure of a PT 3rd stage wheel, and subsequent loss 
of engine power, release of debris and damage to the helicopter, and 
loss of control of the helicopter.
    Accordingly, EASA AD 2020-0266 requires revising the Normal 
Procedures

[[Page 31195]]

Section of the applicable RFM or RFM supplement, informing flight 
crews, and installing a placard in full view of both pilots.

FAA's Determination

    These helicopters have been approved by EASA and are approved for 
operation in the United States. Pursuant to the FAA's bilateral 
agreement with the European Union, EASA has notified the FAA about the 
unsafe condition described in its AD. The FAA is proposing this AD 
after evaluating all known relevant information and determining that 
the unsafe condition described previously is likely to exist or develop 
on other helicopters of these same type designs.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Airbus Helicopters Alert Service Bulletin No. 
AS355-71.00.21, Revision 1, dated November 10, 2020. This service 
information specifies replacing a note with a caution in the Flight 
Manual to not allow rotor speed to stagnate between 279 and 374 
revolutions per minute (RPM) during engine acceleration. This service 
information also specifies procedures for making and installing a label 
(placard) for the pilot and co-pilot to avoid 71-95% N2 steady-state 
speed (avoid operation at 279-374 RPM).
    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.

Other Related Service Information

    The FAA also reviewed Rolls-Royce Alert Commercial Engine Bulletin 
A-1400, Revision 7, dated January 10, 2019. This service information 
specifies the speed avoidance range and operating procedures depending 
on the PT wheel part number installed.

Proposed AD Requirements in This NPRM

    This proposed AD would require revising the existing RFM for your 
helicopter to replace a note with a caution to not allow rotor speed to 
stagnate between 279 and 374 RPM. This proposed AD would also require 
installing a placard to avoid 71-95% N2 steady-state speed (avoid 
operation at 279-374 RPM).

Differences Between This Proposed AD and the EASA AD

    EASA AD 2020-0266 requires compliance within 50 flight hours or 30 
days, whichever occurs first after the effective date of its AD, 
whereas this proposed AD would require compliance within 50 hours time-
in-service after the effective date of this AD instead.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 29 helicopters of U.S. Registry. Labor rates are estimated at 
$85 per work-hour. Based on these numbers, the FAA estimates the 
following costs to comply with this proposed AD.
    Revising the existing RFM for your helicopter would take about 0.25 
work-hour for an estimated cost of $21 per helicopter and $609 for the 
U.S. fleet. Installing a placard would take about 0.25 work-hour and 
parts would cost a nominal amount, for an estimated cost of $21 per 
helicopter and $609 for the U.S. fleet.

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

    The FAA 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) Would not affect intrastate aviation in Alaska, and
    (3) Would 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.

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 adding the following new airworthiness 
directive:

Airbus Helicopters: Docket No. FAA-2021-0460; Project Identifier 
MCAI-2020-01620-R.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by July 26, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Airbus Helicopters Model AS355E, AS355F, 
AS355F1, and AS355F2 helicopters, certificated in any category, with 
a Rolls-Royce Corporation (formerly Allison) engine Model 250-C20F 
installed.

(d) Subject

    Joint Aircraft Service Component (JASC) Code: 7250, Turbine 
Section.

(e) Unsafe Condition

    This AD was prompted by multiple fatigue cracks in power turbine 
(PT) 3rd stage wheels. The FAA is issuing this AD to prevent fatigue 
failure of a PT 3rd stage wheel. The unsafe condition, if not 
addressed, could result in loss of engine power, release of debris 
and damage to the helicopter, and loss of control of the helicopter.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    Within 50 hours time-in-service after the effective date of this 
AD:
    (1) Revise the existing Rotorcraft Flight Manual (RFM) for your 
helicopter by inserting the page applicable to your helicopter model 
and version from Appendix 4.A. through D., of Airbus Helicopters 
Alert Service Bulletin No. AS355-71.00.21, Revision 1, dated 
November 10, 2020 (ASB AS355-71.00.21 Rev 1). Inserting a different 
document with information identical to that in Appendix 4.A. through 
D., of ASB AS355-

[[Page 31196]]

71.00.21 Rev 1, as applicable to your helicopter model and version, 
is acceptable for compliance with the requirement of this paragraph. 
The action required by this paragraph may be performed by the owner/
operator (pilot) holding at least a private pilot certificate and 
must be entered into the aircraft records showing compliance with 
this AD in accordance with Sec.  43.9(a)(1) through (4) and Sec.  
91.417(a)(2)(v). The record must be maintained as required by Sec.  
91.417, Sec.  121.380, or Sec.  135.439.
    (2) Install a placard in full view of the pilot and co-pilot by 
following the Accomplishment Instructions, paragraph 3.B., of ASB 
AS355-71.00.21 Rev 1.
    Note 1 to paragraph (g)(2): Airbus Helicopters service 
information refers to a placard as a label.

(h) Special Flight Permits

    Special flight permits are permitted so long as continuous 
engine operation between 71 and 88% N2 is avoided.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, International Validation Branch, FAA, has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, 
send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the manager of the International Validation Branch, send 
it to the attention of the person identified in paragraph (j)(1) of 
this AD. Information may be emailed to: 9-AVS-AIR-730-AMOC@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(j) Related Information

    (1) For more information about this AD, contact Michael 
Hughlett, Aerospace Engineer, General Aviation & Rotorcraft Section, 
International Validation Branch, FAA, 10101 Hillwood Pkwy., Fort 
Worth, TX 76177; telephone (817) 222-5110; email 
michael.hughlett@faa.gov.
    (2) For service information identified in this AD, contact 
Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; 
telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or 
at https://www.airbus.com/helicopters/services/technical-support.html. You may view this referenced 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.
    (3) The subject of this AD is addressed in European Union 
Aviation Safety Agency (EASA) AD 2020-0266, dated December 8, 2020. 
You may view the EASA AD on the internet at https://www.regulations.gov in Docket No. FAA-2021-0460.

    Issued on June 6, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-12226 Filed 6-10-21; 8:45 am]
BILLING CODE 4910-13-P