DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0463; Project Identifier 2018-SW-050-AD]
Airworthiness Directives; Leonardo S.p.a. Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for Leonardo S.p.a. (Leonardo) Model AB139 and AW139 helicopters with
certain main rotor blades MRB installed. This proposed AD was prompted
by a report of an in-flight loss of a main rotor blade (MRB) tip cap.
This proposed AD would require inspecting the MRB tip cap for
disbonding. 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 August
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow
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 service information identified in this NPRM, contact Leonardo
S.p.A. Helicopters, Emanuele Bufano, Head of Airworthiness, Viale
G.Agusta 520, 21017 C.Costa di Samarate (Va) Italy; telephone +39-0331-
225074; fax +39-0331-229046; or at https://customerportal.leonardocompany.
com/en-US/. 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-2021-0463 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
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.
FOR FURTHER INFORMATION CONTACT: Bang Nguyen, Aerospace Engineer,
Certification Section, Fort Worth ACO Branch, Compliance &
Airworthiness Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX
76177; telephone (817) 222-4973; email email@example.com.
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-2021-0463; Project Identifier
2018-SW-050-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. 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 Bang
Nguyen, Aerospace Engineer, Certification Section, Fort Worth ACO Branch,
Compliance & Airworthiness Division, FAA, 10101 Hillwood Pkwy, Fort Worth,
TX 76177; telephone (817) 222-4973; email firstname.lastname@example.org. Any commen-
tary that the FAA receives which is not specifically designated as CBI
will be placed in the public docket for this rulemaking.
On January 22, 2018, the FAA issued AD 2018-03-01, Amendment 39-
19174 (83 FR 4136, January 30, 2018) (AD 2018-03-01) for Agusta S.p.A.
(now Leonardo) Model AB139 and AW139 helicopters with MRB part number
(P/N) 3G6210A00131 with a serial number (S/N) 3615, 3634, 3667, or 3729
installed. AD 2018-03-01 requires inspecting the MRB tip cap for
disbonding and was prompted by EASA AD 2017-0175-E, dated September 13,
2017 (EASA AD 2017-0175-E), issued by EASA, which is the Technical
Agent for the Member States of the European Union. EASA advised of an
in-flight loss of an MRB tip cap on an AW139 helicopter where the pilot
was able to safely land the helicopter. EASA further advised that an
investigation determined the cause as incorrect bonding procedures used
during production on MRB P/N 3G6210A00131, S/N 3615, 3634, 3667, and
3729. According to EASA, this condition could result in loss of an MRB
tip cap, increased pilot workload, and reduced control of the
helicopter. To address this unsafe condition, EASA AD 2017-0175-E
requires a one-time inspection of the affected MRB tip caps within 5
hours and replacing the affected MRBs within 10 hours if not replaced
as a result of the inspection. EASA AD 2017-0175-E also prohibits
installing the affected MRBs on a helicopter. AD 2018-03-01 requires
the same corrective actions.
Actions Since AD 2018-03-01 Was Issued
After the FAA issued AD 2018-03-01, EASA issued EASA AD 2018-0130,
dated June 18, 2018 (EASA AD 2018-0130), to correct the same unsafe
condition for Leonardo AB139 and AW139 helicopters with additional
serial-numbered MRBs installed. EASA advises that further
investigations after EASA AD 2017-0175-E was issued determined that
another batch of P/N 3G6210A00131 MRBs may have been subject to the
incorrect bonding procedure, but to a less critical extent. EASA AD
2018-0130, which neither revises nor supersedes EASA AD 2017-0175-E,
applies to the following serial-numbered MRBs with less than 1,200
flight hours: 2709, 3558, 3624, 3707, 3790, 3486, 3561, 3625, 3717,
3795, 3488, 3569, 3626, 3720, 3798, 3495, 3570, 3627, 3725, 3803, 3500,
3574, 3628, 3726, 3807, 3501, 3575, 3633, 3734, 3812, 3502, 3582, 3636,
3735, 3822, 3503, 3583, 3638, 3738, 3824, 3508, 3586, 3642, 3739, 3825,
3510, 3590, 3648, 3741, 3827, 3513, 3592, 3649, 3743, 3831, 3520, 3595,
3650, 3744, 3832, 3527, 3597, 3651, 3745, 3838, 3528, 3599, 3657, 3753,
3841, 3529, 3602, 3665, 3754, 3842, 3531, 3603, 3672, 3761, 3847, 3536,
3605, 3682, 3766, 3850, 3539, 3609, 3684, 3770, 3851, 3544, 3612, 3686,
3771, 3852, 3549, 3613, 3690, 3777, 3853, 3551, 3616, 3691, 3783, 3854,
3556, 3620, 3695, 3788, 3855, 3557, 3622, 3696, and 3789.
Accordingly, EASA AD 2018-0130 requires within 50 flight hours (FH)
and thereafter at intervals not to exceed 50 FH, tap inspecting the MRB
for disbonding. If there is disbonding within permitted limits, EASA AD
2018-0130 requires tap inspecting the disbonded area within 10 FH and
thereafter at intervals not to exceed 10 FH. If disbonding that exceeds
the permitted limits is found during any inspection, EASA AD 2018-0130
requires replacing the part. EASA AD 2018-0130 also prohibits
installing the affected part unless it is a serviceable part and
includes a terminating action for the repetitive inspections, which is
accumulation of 1,200 FH by an affected part without findings of
disbonded area, or findings of disbonded area within the limits
specified in Annex A of Leonardo Helicopters Alert Service Bulletin No.
139-520, dated April 26, 2018 (ASB 139-520).
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 the same type designs.
Related Service Information Under 1 CFR Part 51
The FAA reviewed ASB 139-520. This service information specifies
procedures for repetitively inspecting the tip cap on a certain batch
of MRBs for disbonding using a tap test and replacing the MRB if
disbonding is not within permitted limits.
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.
Proposed AD Requirements in This NPRM
This proposed AD would require, for helicopters with affected MRBs
with less than 1,200 total hours time-in-service (TIS) installed,
within 50 hours TIS, tap inspecting each MRB tip cap for disbonding
using a tap hammer or equivalent. If there is no disbonding, tap
inspecting the MRB tip cap at intervals not to exceed 50 hours TIS
would be required. If there is any disbonding that does not exceed the
specified limits in ASB 139-520, tap inspecting the MRB would be
required at intervals not to exceed 10 hours TIS. If there is any
disbonding that exceeds the specified limits in ASB 139-520, removing
the MRB from service would be required before further flight. The
accumulation of 1,200 total hours TIS on the affected part without
findings of any disbonded area or with findings of any disbonded area
that is within the permitted limits in Annex A of ASB 139-520 would
constitute terminating action for the proposed repetitive inspections.
This proposed AD would also prohibit installing any MRB that is
identified in the applicability section on any helicopter.
Differences Between This Proposed AD and the EASA AD
EASA AD 2018-0130 allows replacing an affected part with a
serviceable part, which is marked with the letter "R" (repaired tip
cap) as the last digit of the serial number, as a terminating action
for the repetitive inspections specified in that AD, whereas this
proposed AD would not.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 114 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.
Tap inspecting an MRB tip cap would require 1 work-hour, for a cost
per helicopter of $85 per inspection cycle for a total U.S. fleet cost
of $9,690. Replacing 1 MRB, if required, would take 4 work-hours, and
required parts would cost $141,725, for a total cost of $142,065 per
The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this proposed
AD may be covered under warranty, thereby reducing the cost impact on
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.
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
(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
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 adding the following new airworthiness