DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-1182; Product Identifier 2018-SW-036-AD]
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 supersede Airworthiness Directive (AD)
2016-08-20 for certain Airbus Helicopters (previously Eurocopter
France) EC130B4 and EC130T2 helicopters. AD 2016-08-20 requires
repetitively inspecting the tail boom to Fenestron junction frame
(junction frame) for a crack. Since the FAA issued AD 2016-08-20,
additional cracks have been reported and a design change that modifies
the junction frame has become available. This proposed AD would
continue to require inspecting the junction frame with the horizontal
stabilizer removed, and would propose to expand the applicability,
revise the compliance time and the inspection procedures for inspecting
the junction frame, add inspection procedures for certain helicopters,
allow repair of the junction frame, and would require modifying and
then repetitively inspecting the junction frame and reporting certain
information. The actions of this proposed AD are intended to address an
unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by April 5,
2021.

ADDRESSES: You may send comments by any of the following methods:

Federal eRulemaking Docket: Go to https://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 https://
www.regulations.gov by searching for and locating Docket No. FAA-2020-
1182; 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 proposed AD, the European Aviation Safety Agency (now European
Union Aviation Safety Agency) (EASA) AD, any comments received, and
other information. The street address for Docket Operations is listed
above. Comments will be available in the AD docket shortly after
receipt.

For service information identified in this proposed 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 https://
www.airbus.com/helicopters/services/technical-support.html. You may
view 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: Kristi Bradley, Aviation Safety
Engineer, General Aviation & Rotorcraft Section, International
Validation Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177;
telephone 817-222-5110; email kristin.bradley@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-2020-1182; Product Identifier
2018-SW-036-AD 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.

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 proposal.

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
Kristi Bradley, Aviation Safety Engineer, General Aviation & Rotorcraft
Section, International Validation Branch, FAA, 10101 Hillwood Pkwy.,
Fort Worth, TX 76177; telephone 817-222-5110; email
kristin.bradley@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.

Discussion

The FAA issued AD 2016-08-20, Amendment 39-18497 (81 FR 26103, May
2, 2016) (2016-08-20), for Airbus Helicopters Model EC130B4 and EC130T2
helicopters with a junction frame that has 690 or more hours time-in-
service (TIS) installed. AD 2016-08-20 requires dye penetrant and
borescope inspecting around the circumference of the junction frame for
a crack and replacing any cracked junction frame. AD 2016-08-20 was
prompted by EASA AD 2015-0033-E, dated February 24, 2015 (EASA AD 2015-
0033-E), issued by EASA, which is the Technical Agent for the Member
States of the European Union, to supersede an existing EASA AD. EASA
had determined that it was necessary to define an inspection interval
in sling cycles in addition to the existing flight hour inspection
interval. EASA also acknowledged an alternative method to inspect from
the outside of the tail boom.

Actions Since AD 2016-08-20 Was Issued

Since the FAA issued AD 2016-08-20, EASA has issued a series of
ADs, the most recent being EASA AD 2018-0104, dated May 4, 2018 (EASA
AD 2018-0104), to correct an unsafe condition for Airbus Helicopters
(formerly Eurocopter, Eurocopter France) Model EC 130 B4 and EC 130 T2
helicopters, all serial numbers, except those with Airbus modification
(MOD) 074775 installed. EASA's initial AD was prompted by two incidents
of crack propagation through the junction frame that initiated in the
lower right-hand side between the web and the flange where the lower
spar of the tail boom is joined. EASA states the cracks were of a
significant length and not visible from the outside of the helicopter.
EASA advised that this condition, if not detected, could lead to
structural failure, possibly resulting in Fenestron detachment and
consequent loss of control of the helicopter.

Following EASA AD 2015-0033-E, EASA revised its AD to EASA AD 2015-
0033R1, dated May 3, 2016 (EASA AD 2015-0033R1), which was prompted by
the determination that it was not necessary to inspect junction frames
that had accumulated less than 1,200 flight hours. Accordingly, EASA AD
2015-0033R1 extended the inspection threshold from 700 flight hours to
1,200 flight hours. Thereafter, EASA issued EASA AD 2016-0240, dated
December 2, 2016 (EASA AD 2016-0240) to supersede EASA AD 2015-0033R1.
EASA AD 2016-0240 was prompted by a third incident of cracking in the
same area of the junction frame as the first two incidents.
Investigation determined that detection of the crack was delayed
because of insufficient cleaning of the inspection area inside the
junction frame. For that reason, EASA AD 2016-0240 retained the
requirements of EASA AD 2015-0033R1 and added additional cleaning
requirements before inspecting. After EASA AD 2016-0240 was issued, a
fourth incident of cracking in the same area of the junction frame as
the first three incidents was reported. This fourth incident prompted
EASA to issue EASA AD 2017-0066-E, dated April 21, 2017 (EASA AD 2017-
0066-E) to supersede EASA AD 2016-0240. This fourth incident occurred
on a junction frame that had accumulated significantly less flight
hours than the first three incidents. In light of this, EASA AD 2017-
0066-E retained the requirements of EASA AD 2016-0240 and reduced the
inspection threshold. Shortly after, EASA issued EASA AD 2017-0080,
dated May 5, 2017 (EASA AD 2017-0080) to supersede EASA AD 2017-0066-E.
EASA AD 2017-0080 was prompted by the determination that improved
procedures to remove the horizontal stabilizer before cleaning and
inspecting were necessary for certain helicopters. Accordingly, EASA AD
2017-0080 retained the requirements of EASA AD 2017-0066-E and added
the improved procedures. Since EASA issued EASA AD 2017-0080, Airbus
Helicopters developed MOD 074775, which consists of the installation of
four carbon patches at the junction frame. Installation of MOD 074775,
either in production or by retrofit, constitutes terminating action for
the repetitive inspections. Based on the latest information, EASA
determined that continued inspections may not adequately address the long-
term risk and requires modifying the affected helicopters, which also
terminates the repetitive inspections of the pre-modified configuration.
Accordingly, EASA issued EASA AD 2018-0104 to supersede EASA AD 2017-0080
to require installation of MOD 074775.

Also since the FAA issued AD 2016-08-20, it has been determined
that the dye penetrant inspections required by AD 2016-08-20 are
unnecessary because visual inspections are adequate to inspect for
cracks in the affected area instead.

As a result of the EASA-issued ADs and the further incidents of
cracked junction frames, this proposed AD proposes to expand the
applicability to include all Airbus Helicopters Model EC130B4 and
EC130T2 helicopters with a junction frame, regardless of how many hours
TIS have accumulated on the junction frame; revise the compliance time
to inspect the junction frame with the horizontal stabilizer removed to
depend on the hours TIS accumulated on the junction frame; change the
inspection of the junction frame with the horizontal stabilizer removed
from the dye-penetrant inspection required by AD 2016-08-20 to a visual
inspection; add inspection procedures for helicopters with a skin cut-
out at the junction frame; allow repairing a junction frame in
accordance with an FAA approved repair procedure; require the
installation of MOD 074775 or the four carbon patches reinforcements;
and require repetitive inspections of a modified junction frame.

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 of the
unsafe condition described in its AD. The FAA is proposing this AD
after evaluating all of the information provided by EASA and
determining the unsafe condition exists and is likely to exist or
develop on other helicopters of these same type designs.

Related Service Information Under 1 CFR Part 51

Airbus Helicopters has issued Emergency Alert Service Bulletin No.
05A017, Revision 7, dated March 21, 2018, for Model EC130 B4 and T2
helicopters without MOD 074775 installed. This service information
specifies procedures for cleaning inside the junction frame, inspecting
the junction frame from the inside of the tail boom with the horizontal
stabilizer both removed and installed for a crack, and inspecting the
junction frame from the outside of the tail boom for a crack.

Airbus Helicopters has issued Service Bulletin No. EC130-53-036,
Revision 4, dated April, 28, 2020, for Model EC130 B4 and T2
helicopters without MOD 074609 or 074775 installed and on which the
skin of the junction frame area has not been repaired. This service
information specifies procedures to reinforce the junction frame (MOD
074775) by replacing the two lateral splices which join the skins with
four carbon patches (left-hand side, right-hand side, and lower sides).

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

Airbus Helicopters has issued Service Bulletin No. EC130-53-029,
Revision 1, dated January 27, 2016. This service information specifies
procedures to make a cut-out of the splice and skin at the junction
frame (MOD 350A087421).

Airbus has issued EC 130 B4 Chapter 4, Airworthiness Limitations
Section, Revision 11, dated January 19, 2019 and EC 130 T2 Chapter 4,
Airworthiness Limitations Section, Revision 9, dated September 9, 2019,
which specify visually checking the junction frame for cracks at an
interval of 600 flight hours with a margin of 60 flight hours.

Airbus Helicopters has also issued Section 55-11-00, 6-4--
Horizontal Stabilizer--Inspection/Check, of Aircraft Maintenance Manual
EC130, dated November 9, 2017, which specifies procedures for cleaning
inside the junction frame and inspecting the junction frame from the
inside of the tail boom with the horizontal stabilizer removed.

Proposed AD Requirements

This proposed AD would require:

For helicopters without MOD 074775, or MOD AH 350A087421
or SB EC130-53-029 installed, at a compliance time based on the hours
TIS accumulated on the junction frame, removing the horizontal
stabilizer, cleaning the junction frame, and visually inspecting the
junction frame area for a crack, paying particular attention to the
area around the 4 spars.
- Following the initial visual inspection, within 25 hours TIS
or 390 sling cycles, whichever comes first, and thereafter at intervals
not exceeding 25 hours TIS or 390 sling cycles, whichever comes first,
either repeating the initial visual inspection, or, if the surface area
is clean, borescope inspecting the junction frame area for a crack,
paying particular attention to the area around the 4 spars.

- Also following the initial visual inspection, within 150
hours TIS and thereafter at intervals not to exceed 150 hours TIS,
repeating the initial visual inspection.

For helicopters without MOD 074775 installed, but with MOD
AH 350A087421 or SB EC130-53-029 installed, before the junction frame
accumulates 350 hours TIS or within 10 hours TIS, whichever occurs
later, visually inspecting for a crack on the junction frame area in
each skin cut-out area.

- Following the initial visual inspection, within 10 hours TIS
or 250 sling cycles, whichever occurs first, and thereafter at
intervals not exceeding 10 hours TIS or 250 sling cycles, whichever
occurs first, repeating the initial visual inspection.

- Also following the initial visual inspection, within 660
hours TIS and thereafter at intervals not to exceed 660 hours TIS,
removing the horizontal stabilizer, cleaning the junction frame, and
dye-penetrant inspecting the junction frame area for a crack, paying
particular attention to the area around the 4 spars.

If there is a crack, replacing or repairing the junction
frame in accordance with an FAA approved repair procedure before
further flight. Repairing the junction frame would not constitute
terminating action for the requirements of this proposed AD.

For helicopters without MOD 074775 installed, with or
without MOD AH 350A087421 or SB EC130-53-029 installed, without MOD
074609 or SB 53-024 installed, and on which the skin of the junction
frame area has never been repaired, installing MOD 074775 within 24
months as of the effective date of this AD and reporting certain
information to Airbus Helicopters within 30 days after installing MOD
074775.

For helicopters without MOD 074775 installed, with MOD
074609 or SB 53-024 installed, or on which the skin of the junction
frame area has been previously repaired at any time, reinforcing the
junction frame by replacing the two lateral splices which join the
skins with four carbon patches (left-hand side, right-hand side, and
lower sides) within 24 months as of the effective date of this AD.

For helicopters with MOD 074775 installed or with the four
carbon patches reinforcements installed, but without
MOD 074581 for Model EC130T2 helicopters, within 600 hours TIS after
the installation of MOD 074775 or the reinforcement, and thereafter at
intervals not exceeding 600 hours TIS, visually inspect the junction
frame area for a crack. If there is a crack, replacing or repairing the
junction frame in accordance with an FAA approved repair procedure
before further flight. Repairing the junction frame would not
constitute terminating action for the requirements of this proposed AD.

Differences Between This Proposed AD and the EASA AD

EASA AD 2018-0104 does not apply to helicopters with MOD 074775,
whereas this proposed AD does. EASA AD 2018-0104 requires performing a
local non-destructive inspection if in doubt about if there is a crack,
whereas this proposed AD does not. EASA AD 2018-0104 allows the pilot
to visually inspect the junction frame from outside the tail boom for a
crack, whereas this proposed AD does not. EASA AD 2018-0104 requires
contacting Airbus Helicopters if any crack is detected, whereas this
proposed AD would require replacing or repairing the junction frame in
accordance with an FAA approved repair procedure instead. This proposed
AD would require a repetitive inspection for helicopters with MOD
074775 installed, whereas the EASA AD does not.

Costs of Compliance

The FAA estimates that this proposed AD affects 263 helicopters of
U.S. Registry. Labor costs are estimated at $85 per work-hours. Based
on these numbers, the FAA estimates that operators may incur the
following costs in order to comply with this proposed AD.

Cleaning and inspecting the junction frame area with the horizontal
stabilizer removed would take about 1 work-hour for an estimated cost
of $85 per helicopter and $22,355 for the U.S. fleet, per inspection
cycle.

Internally borescope inspecting the junction frame area with the
horizontal stabilizer installed would take about 0.5 work hour for an
estimated cost of $43 per helicopter and $11,309 for the U.S. fleet,
per inspection cycle.

If applicable, cleaning and inspecting the junction frame area in
each skin cut-out area would take about 1.25 work-hour for an estimated
cost of $106 per helicopter and $27,878 for the U.S. fleet, per
inspection cycle.

Modifying the junction frame skin reinforcements would take about
90 work-hours and parts cost about $10,000 for an estimated cost of
$17,650 per helicopter and $4,641,950 for the U.S. fleet. Reporting
certain information would take about 1 work-hour for an estimated cost
of $85 per helicopter and $22,355 for the U.S. fleet. Inspecting the
modified junction frame area would take about 1 work-hour for an
estimated cost of $85 per helicopter and $22,355 for the U.S. fleet,
per inspection cycle.

If required, repairing or replacing the junction frame would take
up to 50 work-hours and parts would cost about $60,000 for an estimated
cost of $64,250 per helicopter.

According to Airbus Helicopters' service information, some of the
costs of this proposed AD may be covered under warranty, thereby
reducing the cost impact on affected individuals. The FAA does not
control warranty coverage by Airbus Helicopters. Accordingly, the FAA
has included all costs in this cost estimate.

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 OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to be
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden, to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.

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 that this proposed regulation:

1. Is not a "significant regulatory action" under Executive Order
12866,

2. Will not affect intrastate aviation in Alaska, and

3. 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.

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

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:

a. Removing Airworthiness Directive (AD) 2016-08-20, Amendment 39-18497
(81 FR 26103, May 2, 2016); and

b. Adding the following new AD: