DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-1696; Project Identifier MCAI-2023-01234-A;
Amendment 39-22850; AD 2024-19-08]
RIN 2120-AA64

Airworthiness Directives; Diamond Aircraft Industries Inc. (Type
Certificate Previously Held by Diamond Aircraft Industries GmbH)
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2009-10-04
for certain Diamond Aircraft Industries GmbH (type certificate now held
by Diamond Aircraft Industries Inc.) Model DA 40 and DA 40 F airplanes.
AD 2009-10-04 required repetitively inspecting the nose landing gear
(NLG) leg for cracks and replacing the NLG leg if cracks are found.
Since the FAA issued AD 2009-10-04, Transport Canada updated mandatory
continuing airworthiness information (MCAI) to correct this unsafe
condition on these products. This AD results from changes made to the
part replacement options and the repetitive inspections. This AD
requires doing repetitive detailed inspections of the NLG leg pivot
axle for cracking and if cracking is found replacing that part with a
serviceable part. This AD also requires eventually replacing all NLG
legs having certain part numbers with serviceable parts, if not already
done, and prohibits installing affected parts. Replacing affected parts
with serviceable parts is terminating action for the repetitive
inspections specified in this AD. The FAA is issuing this AD to address
the unsafe condition on these products.

DATES: This AD is effective November 29, 2024.

The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of November 29, 2024.

ADDRESSES:

AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-1696; 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 Diamond Aircraft Industries Inc. material identified
in this AD, contact Diamond Aircraft Industries Inc., 1560 Crumlin
Sideroad, London, ON, Canada, N5V 1S2; phone: (519) 457-4041; email:
support-canada@diamondaircraft.com; website: diamondaircraft.com.

You may view this material 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-2024-1696.

FOR FURTHER INFORMATION CONTACT: Gabriel Kim, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (516)
228-7300; email: 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2009-10-04, Amendment 39-15899 (74 FR
22435, May 13, 2009) (AD 2009-10-04). AD 2009-10-04 applied to certain
Diamond Aircraft Industries GmbH (type certificate now held by Diamond
Aircraft Industries Inc.) Model DA 40 and DA 40 F airplanes. AD 2009-
10-04 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 AD 2009-0016, dated January
22, 2009 (EASA AD 2009-0016), to address fatigue cracking of the NLG
leg part number (P/N) D41-3223-10-00 at the pivot axle.

AD 2009-10-04 superseded and maintained the requirements of AD
2007-17-06, Amendment 39-15164 (72 FR 46549, August 21, 2007), which
required repetitively inspecting the NLG leg for cracks and replacing
the NLG leg if cracks were found. The FAA issued AD 2009-10-04 to
exclude from the applicability any airplanes that had the improved NLG
leg installed.

Effective November 15, 2017, the design and oversight
responsibilities for the Model DA 40, DA 40 F, and DA 40 D airplanes
were transferred from Diamond Aircraft Industries GmbH of Austria as
the design approval holder, and EASA as the civil aviation authority,
to Diamond Aircraft Industries Inc. (Diamond), of Canada as the new
design approval holder, and Transport Canada as the civil aviation
authority. After that transition, Transport Canada received several in-
service reports of P/N D41-3223-10-00_1 cracking at the pivot axle and
in some cases, fracture of the NLG leg. Investigation revealed that the
failures were the result of fatigue cracking.

Since the FAA issued AD 2009-10-04, Transport Canada superseded
EASA AD 2009-0016 and issued Transport Canada AD CF-2023-50, dated July
10, 2023 (Transport Canada AD CF-2023-50), to address failure of the
NLG leg at the pivot axle by requiring initial and repetitive detailed
inspections of NLG leg P/N D41-3223-10-00 and P/N D41-3223-10-00_1 to
detect cracking, replacing a NLG leg, as required, with a serviceable
part, and prohibiting the installation of NLG leg P/N D41-3223-10-00 or
P/N D41-3223-10-00_1 as a replacement part.

Transport Canada AD CF-2023-50 differed from the Diamond material
because Transport Canada AD CF-2023-50 required a detailed inspection
of the pivot axle of the NLG leg P/N D41-3223-10-00 and P/N D41-3223-
10-00_1 using a bright light and 10X magnifying glass instead of Type
II visible dye for the inspection of the pivot axle. After Transport
Canada AD CF-2023-50 was issued, the repetitive inspection interval was
increased from 100 hours air time to 110 hours air time to align with
the scheduled 100-hour inspection in chapter 5 of the DA 40 series
Airplane Maintenance Manual. To require the change to Transport Canada
AD CF-2023-50, Transport Canada issued AD CF-2023-50R1, dated November
29, 2023 (also referred to as the MCAI). The MCAI was published to
address the time interval change of the repetitive inspection from 100-
hour intervals to 110-hour intervals.

The NPRM published in the Federal Register on July 5, 2024 (89 FR
55525). The NPRM was prompted by failure of a NLG in the area of the
pivot axle and changes made to the part replacement options and the
repetitive inspections as detailed in the MCAI. The MCAI was published
to address the time interval change of the repetitive inspection from
100-hour intervals to 110-hour intervals to align with the scheduled
100-hour inspection in chapter 5 of the DA 40 series Airplane
Maintenance Manual.

In the NPRM, the FAA proposed to require repetitive detailed
inspections of the NLG leg pivot axle for cracking and if cracking was
found replacing that part with a serviceable part. In the NPRM, the FAA
also proposed to require eventually replacing all NLG legs having
certain part numbers with serviceable parts, if not already done, and
prohibit installing affected parts. Replacing affected parts with
serviceable parts is terminating action for the repetitive inspections
required by this AD.

The FAA is issuing this AD to address the unsafe condition on these products.

You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2024-1696.

Discussion of Final Airworthiness Directive

Comments

The FAA received no comments on the NPRM or on the determination of
the costs.

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 referenced above. The FAA reviewed the relevant data 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.

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed Diamond Mandatory Service Bulletin MSB 40-091,
Rev. 0, dated January 18, 2021, published with Diamond Aircraft
Industries Work Instruction WI-MSB 40-091, Rev. 0, dated January 18,
2021 (issued as one document). This material specifies procedures for
doing repetitive dye penetrant inspections of the NLG leg pivot axle
for cracking and replacing the NLG for Model DA 40 airplanes.

The FAA also reviewed Diamond Mandatory Service Bulletin MSB F4-
038, Rev. 0, dated January 18, 2021, published with Diamond Aircraft
Industries Work Instruction WI-MSB F4-038, Rev. 0, dated January 18,
2021 (issued as one document). This material specifies procedures for
doing repetitive dye penetrant detailed inspections of the NLG leg
pivot axle for cracking and replacing the NLG for Model DA 40 F airplanes.

This material 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, the MCAI, and the Material

The MCAI applies to Model DA 40 D airplanes, however, this AD does
not because that model does not have an FAA type certificate.

Although the Diamond material specifies to do dye penetrant
inspections, the MCAI requires, and this AD requires, using a bright
light (minimum of 100 foot-candles) and 10X magnifying glass instead of
dye penetrant.

Costs of Compliance

The FAA estimates that this AD affects 693 airplanes of U.S. registry.

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

Estimated Costs

The costs of the inspection and replacement of the NLG leg are
based on all airplanes having an affected NLG installed. The FAA has no
way of determining the number of airplanes that have the affected NLG
installed, and those that do not have one installed are only affected
by the installation prohibition.

The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected operators.

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 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
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:

a. Removing Airworthiness Directive 2009-10-04, Amendment 39-15899 (74
FR 22435, May 13, 2009); and

b. Adding the following new airworthiness directive: