DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0795; Project Identifier 2019-CE-054-AD; Amendment
39-21837; AD 2021-24-16]
RIN 2120-AA64

Airworthiness Directives; Daher Aerospace (Type Certificate
Previously Held by SOCATA) 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 all
Daher Aerospace (type certificate previously held by SOCATA) Model TB
20 and TB 21 airplanes. This AD was prompted by mandatory continuing
airworthiness information (MCAI) originated by an aviation authority of
another country to identify and correct an unsafe condition on an
aviation product. The MCAI describes the unsafe condition as cracks on
the main landing gear (MLG) legs. This AD requires repetitively
inspecting the MLG and performing all applicable corrective actions.
The FAA is issuing this AD to address the unsafe condition on these
products.

DATES: This AD is effective January 18, 2022.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of January 18,
2022.

ADDRESSES: For service information identified in this final rule,
contact Daher Aircraft Inc., Pompano Beach Airpark, 601 NE 10 Street,
Pompano Beach, FL 33060; phone: (954) 893-1400; website: www.tbm.aero.
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 (816) 329-4148. It is also available at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-0795.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0795; 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: Gregory Johnson, Aviation Safety
Engineer, FAA, General Aviation & Rotorcraft Section, International
Validation Branch, 901 Locust, Room 301, Kansas City, MO 64106; phone:
(720) 626-5462; fax: (816) 329-4090; email: gregory.johnson@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all Daher Aerospace
(type certificate previously held by SOCATA) Model TB 20 and TB 21
airplanes. The NPRM published in the Federal Register on September 17,
2021 (86 FR 51840). 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 AD 2019-
0274, dated November 6, 2019 (referred to after this as ``the MCAI''),
to address an unsafe condition on all Daher Aerospace (formerly SOCATA)
Model TB 20 and TB 21 airplanes. The MCAI states:

Occurrences have been reported of finding cracks on MLG legs of
TB 20 and TB 21 aeroplanes.
This condition, if not detected and corrected, could lead to
structural failure of an MLG leg and consequent MLG collapse,
possibly resulting in damage to the aeroplane and injury to
occupants.
To address this potential unsafe condition, DAHER Aerospace
issued the [service bulletin] SB to provide inspection instructions.
For the reasons described above, this [EASA] AD requires
repetitive special detailed inspections (SDI) using magnetic
particle method of the affected MLG area, and, depending on
findings, accomplishment of applicable corrective action(s).

You may examine the MCAI in the AD docket at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-0795.

Comments

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

Conclusion

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 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.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Daher Aerospace Service Bulletin SB 10-154-32,
dated September 2019. The service information contains procedures for
repetitively inspecting the MLG area for cracks and performing any
rework and repair. 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.

Costs of Compliance

The FAA estimates that this AD affects 52 airplanes of U.S.
registry. The FAA also estimates that it would take about 8 work-hours
per airplane to perform the magnetic particle inspection required by
this AD. The average labor rate is $85 per work-hour.
Based on these figures, the FAA estimates the inspection cost of
this AD on U.S. operators to be $35,360, or $680 per airplane, per
inspection cycle.

In addition, the FAA estimates that any necessary rework would take
12 work-hours and require parts costing $400, for a cost of $1,420 per
airplane. The FAA has no way of determining the number of airplanes
that may need these actions. If the reworked MLG area is found damaged
during a follow-on magnetic particle inspection, because the damage may
vary considerably from airplane to airplane, the FAA has no way of
estimating this repair cost.

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 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: