DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-1070; Project Identifier 2020-CE-004-AD; Amendment
39-22214; AD 2022-21-15]
RIN 2120-AA64

Airworthiness Directives; Diamond Aircraft Industries GmbH Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Diamond Aircraft Industries GmbH (DAI) Model DA 42, DA 42 NG,
and DA 42 M-NG airplanes. This AD is prompted by mandatory continuing
airworthiness information (MCAI) issued by the aviation authority of
another country to identify and correct an unsafe condition on an
aviation product. The MCAI describes the unsafe condition as a loose
rudder T-yoke axle nut. This AD requires replacing the rudder T-yoke
axle with an improved rudder T-yoke axle. The FAA is issuing this AD to
address the unsafe condition on these products.

DATES: This AD is effective December 14, 2022.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 14,
2022.

ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2021-1070; 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 final rule, the MCAI, any comments received, and
other information. The address for Docket Operations 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.
Material Incorporated by Reference:
For service information identified in this final rule,
contact Diamond Aircraft Industries GmbH, N.A. Otto-Strase 5, A-
2700 Wiener Neustadt, Austria; phone: +43 2622 26700; fax: +43 2622
26780; email: office@diamond-air.at; website: diamondaircraft.com.
You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 901 Locust,
Kansas City, MO 64106. For information on the availability of this
material at the FAA, call (817) 222-5110. It is also available at
regulations.gov under Docket No. FAA-2021-1070.

FOR FURTHER INFORMATION CONTACT: Penelope Trease, Aviation Safety
Engineer, General Aviation & Rotorcraft Section, International
Validation Branch, FAA, 26805 E 68th Avenue, Denver, CO 80249; phone:
(303) 342-1094; email: penelope.trease@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain serial-numbered
DAI Model DA 42, DA 42 NG, and DA 42 M-NG airplanes. The NPRM published
in the Federal Register on December 14, 2021 (86 FR 70987). The NPRM
was prompted by MCAI originated by the European Union Aviation Safety
Agency (EASA), which is the Technical Agent for the Member States of
the European Union. EASA issued EASA AD 2019-0302, dated December 13,
2019 (referred to after this as ``the MCAI''), to address the unsafe
condition on DAI Model DA 42, DA 42 M, DA 42 NG, and DA 42 M-NG
airplanes. The MCAI states:

Occurrences were reported of finding a loose rudder T-yoke axle
nut on DA 42 aeroplanes.
This condition, if not detected and corrected, could lead to
vertical movement of the axle, possibly resulting in reduced rudder
control of the aeroplane.
To address this potential unsafe condition, DAI issued the
applicable MSB [Mandatory Service Bulletin], providing instructions
to inspect for correct installation of the self-locking nut to the
affected part.
For the reason described above, this [EASA] AD requires
repetitive inspections for correct installation of the self-locking
nut to the affected part and, depending on findings, accomplishment
of applicable corrective action(s) and replacement of the self-
locking nut. This [EASA] AD also provides an optional terminating
action for the repetitive inspections.

You may examine the MCAI in the AD docket at regulations.gov by
searching for and locating Docket No. FAA-2021-1070.
In the NPRM, the FAA proposed to require replacing the rudder T-
yoke axle with an improved rudder T-yoke axle. The FAA is issuing this
AD to prevent movement of the T-yoke axle. The unsafe condition, if not
addressed, could result in reduced control of the airplane.

Discussion of Final Airworthiness Directive

Comments

The FAA received one comment from DAI. The following presents the
comment received on the NPRM and the FAA's response to the comment.

Request To Include New Mandatory Service Bulletin Published by DAI in
the NPRM

DAI requested that the FAA revise the NPRM to include recently
published Diamond Aircraft Mandatory Service Bulletin DAI MSB 42-143
and MSB 42NG-086, dated December 23, 2021 (issued as one document), and
explained this service bulletin further rectifies the unsafe condition
of the movement of the T-yoke axle by specifying instructions to apply
torque seal marks to the head of the T-yoke axle and to the self-
locking nut. DAI further explained that the temporary revision of the
aircraft maintenance manual (AMM) specifies visual inspection of these
torque seal marks during every annual inspection. According to DAI, the
additional visual inspection of the torque seal marks incorporated in
Diamond Aircraft Mandatory Service Bulletin DAI MSB 42-143 and MSB
42NG-086, dated December 23, 2021, replaces the ``Inspection of Rudder
T-yoke axle Nut for Looseness'' section of Diamond Aircraft Mandatory
Service Bulletin DAI MSB 42-137/1 and MSB 42NG-079/1, dated December
11, 2021 (issued as one document), that was previously mandated by EASA
AD 2019-0302.
The FAA disagrees. In the NPRM, the FAA did not propose to require
the repetitive inspection of the T-yoke axle nut, as specified in Diamond
Aircraft Mandatory Service Bulletin DAI MSB 42-137/1 and MSB 42NG-079/
1, dated December 11, 2021, to correct the unsafe condition, but
instead proposed to require replacement of the rudder T-yoke axle with
an improved rudder T-yoke axle. Therefore, Diamond Aircraft Mandatory
Service Bulletin DAI MSB 42-143 and MSB 42NG-086, dated December 23,
2021, is not required by the FAA to correct the unsafe condition. If
EASA issues an AD to mandate additional actions specified in DAI
service information, the FAA will evaluate the requirements in the EASA
AD and consider additional rulemaking.

Conclusion

These products have been approved by the aviation authority of
another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, it has notified the FAA of the unsafe condition described in
the MCAI and service information referenced above. The FAA reviewed the
relevant data, considered the comment received, and determined that air
safety requires adopting this AD as proposed. Accordingly, the FAA is
issuing this AD to address the unsafe condition on these products. This
AD is adopted as proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Diamond Aircraft Recommended Service Bulletin DAI
RSB 42-139 and DAI RSB 42NG-081, dated October 21, 2019 (issued as one
document), published with DAI Work Instruction WI-RSB 42-139 and WI-RSB
42NG-081, Revision 1, dated October 24, 2019 (issued as one document)
attached. The service bulletin specifies complying with the work
instruction, which contains procedures for replacing the rudder T-yoke
axle with an improved (additional retaining pin) rudder T-yoke axle.
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 ADDRESSES.

Differences Between This AD and the MCAI

The MCAI applies to the Model DA 42 M airplane, and this AD does
not because it does not have an FAA type certificate.
The MCAI requires repetitively inspecting the self-locking nut
until the rudder T-yoke axle is replaced with improved part number (P/
N) D60-5320-00-32. This AD requires installing rudder T-yoke axle P/N
D60-5320-00-32 and does not have an inspection requirement.

Costs of Compliance

The FAA estimates that this AD affects 193 airplanes of U.S.
registry. The FAA estimates that it would take about 6 work-hours to
replace the rudder T-yoke axle and require parts costing $166. The
average labor rate is $85 per work-hour. Based on these figures, the
FAA estimates the cost of this AD on U.S. operators to be $130,468 or
$676 per airplane.

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

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) 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 Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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
directive: