DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-1077; Project Identifier MCAI-2021-00607-A;
Amendment 39-21974; AD 2022-06-08]
Airworthiness Directives; Diamond Aircraft Industries GmbH Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2017-18-
10, which applied to certain Diamond Aircraft Industries GmbH (DAI)
Model DA 42, DA 42 M-NG, and DA 42 NG airplanes. AD 2017-18-10 required
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(EASA) superseded its mandatory continuing airworthiness information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 AD
retains the actions required by AD 2017-18-10, expands the
applicability, and prohibits the installation of certain flap bell
cranks. The FAA is issuing this AD to address the unsafe condition on
DATES: This AD is effective May 9, 2022.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of May 9, 2022.
ADDRESSES: 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; email:
firstname.lastname@example.org; 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. It is also available at https://www.regulations.gov
for and locating Docket No. FAA-2021-1077.
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 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.
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: email@example.com.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2017-18-10, Amendment 39-19019 (82 FR
42029, September 6, 2017) (AD 2017-18-10). AD 2017-18-10 applied to
certain serial-numbered DAI Model DA 42, DA 42 M-NG, and DA 42 NG
airplanes. AD 2017-18-10 required 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.
The NPRM published in the Federal Register on December 23, 2021 (86
FR 72895). The NPRM was prompted by AD 2020-0008, dated January 20,
2020 (referred to after this as ``the MCAI''), issued by EASA, which is
the Technical Agent for the Member States of the European Union. The
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
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.
In the NPRM, the FAA proposed to retain the actions of AD 2017-18-
10 but expand the applicability and prohibit installing a flap bell
crank with part number D60-2757-11-00, up to and including revision "d."
Discussion of Final Airworthiness Directive
The FAA received no comments on the NPRM or on the determination of
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
referenced above. The FAA reviewed the relevant data and determined
that air safety requires adoption of the 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 Mandatory Service Bulletin MSB
42-126/1 and MSB 42NG-066/1, 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 up to and
including revision ``d'' with an improved 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 the ADDRESSES section.
Other Related Service Information
The FAA also reviewed Diamond Aircraft Mandatory Service Bulletin
MSB 42-126 and MSB 42NG-066, dated March 27, 2017 (issued as one
document) published with Diamond Aircraft Industries GmbH Work
Instruction WI-MSB 42-126 and WI-MSB 42NG-066, dated March 27, 2017
(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.
Differences Between This AD and the MCAI
The MCAI applies to DAI Model DA 42 M airplanes, and this AD does
not because it does not have an FAA type certificate.
Costs of Compliance
The FAA estimates that this AD affects 200 airplanes of U.S.
The FAA estimates the following costs to comply with this AD:
||Cost per product
||Cost on U.S. operators
|Initial inspection and modification
||4 work-hours x $85 per hour =
||2 work-hours x $85 per hour =
||$170 per inspection cycle
||$34,000 per inspection cycle
The FAA estimates the following costs
to replace the flap bell
crank based on the results of the inspection. The agency has no way of
determining the number of airplanes that might need this replacement:
|Flap bell crank replacement
||1 work-hour x $85 per hour =
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 has determined that 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
(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
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:
a. Removing Airworthiness Directive 2017-18-10, Amendment 39-19019 (82
FR 42029, September 6, 2017); and
b. Adding the following new airworthiness directive: