DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-1077; Project Identifier MCAI-2021-00607-A]
RIN 2120-AA64

Airworthiness Directives; Diamond Aircraft Industries GmbH
Airplanes

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)
2017-18-10, which applies to certain Diamond Aircraft Industries GmbH
(DAI) Model DA 42, DA 42 M-NG, and DA 42 NG airplanes. AD 2017-18-10
requires modifying the flap control system, repetitively inspecting the
flap bell crank, and replacing the flap bell crank as necessary. Since
the FAA issued AD 2017-18-10, the European Union Aviation Safety Agency
(EASA) superseded its mandatory continuing airworthiness information
(MCAI) to correct an unsafe condition on these products. This proposed
AD would retain the actions required by AD 2017-18-10, expand the
applicability, and prohibit the installation of certain flap bell
cranks. 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 February 7, 2022.

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 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; email: office@diamond-air.at;
website: https://www.diamondaircraft.com. You may view this service
information at the Airworthiness Products Section, Operational Safety
Branch, FAA, 901 Locust, Kansas City, MO 64106. 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-2021-1077; 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; email: penelope.trease@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-2021-1077; Project Identifier
MCAI-2021-00607-A" 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
the 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 proposed AD.

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.

Background

The FAA issued AD 2017-18-10, Amendment 39-19019 (82 FR 42029,
September 6, 2017) (AD 2017-18-10), for certain serial-numbered DAI
Model DA 42, DA 42 M-NG, and DA 42 NG airplanes. AD 2017-18-10 was
prompted by MCAI originated by EASA, which is the Technical Agent for
the Member States of the European Union. EASA issued EASA AD 2017-0074,
dated April 28, 2017, to identify and correct an unsafe condition
identified as cracks and deformation on certain flap bell cranks.

AD 2017-18-10 requires modifying the flap control system by
installing two spacers to replace a single long spacer, repetitively
inspecting the flap bell crank, and replacing the flap bell crank with
an improved part as necessary. The FAA issued AD 2017-18-10 to prevent
failure of the flap bell crank, which could result in reduced control
of the airplane.

Actions Since AD 2017-18-10 Was Issued

Since the FAA issued AD 2017-18-10, EASA superseded EASA AD 2017-
0074, dated April 28, 2017, and issued EASA AD 2020-0008 dated January
20, 2020 (referred to after this as "the MCAI"). The MCAI states:

Occurrences were reported of finding cracks and deformation on
certain flap bell cranks. Investigation results identified frequent
high load conditions as the cause for these events.

This condition, if not detected and corrected, could lead to
failure of the flap bell crank, possibly resulting in reduced
control of the aeroplane.

To address this potential unsafe condition, DAI issued
[Mandatory Service Bulletin] MSB 42-126/42NG-066 and the
corresponding [Work Instructions] WI MSB 42-126/42NG-066 (single
document), providing inspection and modification instructions.
Consequently, EASA issued AD 2017-0074 to require modification of
the flap control system by installing two spacers to
replace a single long spacer, repetitive inspections of the flap
bell crank, and, depending on findings, replacement of the flap bell
crank with an improved part. That [EASA] AD also provided an
optional terminating action by installing an improved flap bell crank.

Since that [EASA] AD was issued, it was determined that early
'Revisions' of P/N D60-2757-11-00 flap bell cranks are no longer
acceptable and should be removed from service. Prompted by that
determination, DAI issued the applicable MSB, as defined in this
[EASA] AD, to provide the relevant instructions.

For the reason described above, this [EASA] AD retains the
requirements of EASA AD 2017-0074, which is superseded, expands the
applicability, and requires removal from service of certain affected
parts.

You may examine the MCAI in the AD docket at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-1077.

EASA made the determination to increase the applicability during a
continued operational safety review. EASA determined that the earlier
versions of the bellcranks could be installed on all serial-numbered
airplanes and expanded the applicability accordingly.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Diamond Aircraft Mandatory Service Bulletin MSB
42-126/1 and MSB 42NG-066/1, Revision 1, dated November 14, 2019
(issued as one document) published with Diamond Aircraft Industries
GmbH Work Instruction WI-MSB 42-126 and WI-MSB 42NG-066, Revision 1,
dated November 14, 2019 (issued as one document) attached. This service
information specifies procedures for inspecting the flap bell crank for
cracks, installing two spacers instead of one long spacer, and
replacing early revisions of the affected flap bell crank. 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.

FAA's Determination

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 retain the actions of AD 2017-18-10 but
would expand the applicability and prohibit installing a flap bell
crank with part number D60-2757-11-00, up to and including revision "d."

Differences Between This Proposed AD and the MCAI

The MCAI applies to DAI Model DA 42 M airplanes, and this proposed
AD would not because it does not have an FAA type certificate.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 200 airplanes of U.S. registry.

The FAA estimates the following costs to comply with this proposed AD:

Estimated Costs

The FAA estimates the following costs to replace the flap bell
crank based on the results of the proposed inspection. The agency has
no way of determining the number of airplanes that might need this replacement:

On-Condition Costs

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 above, I certify that the 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

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 2017-18-10, Amendment 39-19019 (82
FR 42029, September 6, 2017); and

b. Adding the following new airworthiness directive: