DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-1070; Project Identifier 2020-CE-004-AD]
Airworthiness Directives; Diamond Aircraft Industries GmbH Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for certain Diamond Aircraft Industries GmbH (DAI) Model DA 42, DA 42
NG, and DA 42 M-NG airplanes. This proposed AD was 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 proposed AD would
require replacing the rudder T-yoke axle with an improved rudder T-yoke
axle. The FAA is proposing this AD to address the unsafe condition on
DATES: The FAA must receive comments on this proposed AD by January
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
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 above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this NPRM, contact Diamond
Aircraft Industries GmbH, N.A. Otto-Stra[szlig]e 5, A-2700 Wiener
Neustadt, Austria; phone: +43 2622 26700; fax: +43 2622 26780; email:
firstname.lastname@example.org; website: https://www.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
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating 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 NPRM, the MCAI,
any comments received, and other information. The street address for
Docket Operations is listed above.
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; fax: (303) 342-1088; 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-2021-1070; Project Identifier
2020-CE-004-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
Penelope Trease, Aviation Safety Engineer, General Aviation &
Rotorcraft Section, International Validation Branch, FAA, 26805 E 68th
Avenue, Denver, CO 80249. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.
The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Union, has issued
EASA AD 2019-0302, dated December 13, 2019 (referred to after this as
``the MCAI''), to address an unsafe condition on DAI Model DA 42, DA 42
M, DA 42 M-NG, and DA 42 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
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
the repetitive inspections.
You may examine the MCAI in the AD docket at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-1070.
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.
This product has been approved by the aviation authority of another
country and is 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 is issuing this NPRM
after determining the unsafe condition described previously is likely
to exist or develop on other products of the same type design.
Proposed AD Requirements in This NPRM
This proposed AD would require replacing the rudder T-yoke axle
with an improved rudder T-yoke axle.
Differences Between This Proposed AD and the MCAI
The MCAI applies to the Model DA 42 M airplane and this proposed AD
would 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 proposed AD would require installing rudder T-
yoke axle P/N D60-5320-00-32 and would not have an inspection
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 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 proposed 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.
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 above, I certify this proposed
(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