DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0718; Project Identifier 2019-CE-045-AD; Amendment
39-21343; AD 2020-25-01]
RIN 2120-AA64

Airworthiness Directives; Textron Aviation, Inc. Airplanes (Type
Certificate Previously Held by Beechcraft Corporation)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Textron Aviation Inc. (Textron) (type certificate previously
held by Beechcraft Corporation) Models F90, 65-90, 65-A90, B90, C90,
H90 (T-44A), E90, 65-A90-1 (JU-21A, U-21A, RU-21A, RU-21D, U-21G, RU-
21H), 65-A90-2 (RU-21B), 65-A90-3 (RU-21C), 65-A90-4 (RU-21E, RU-21H),
99, 99A, 99A (FACH), A99, A99A, B99, C99, 100, A100 (U-21F), and B100
airplanes. This AD was prompted by reports of fatigue cracks in the
lower forward wing fitting. This AD requires a one-time inspection for
the presence of washer part number (P/N) 90-380058-1 on the left-hand
(LH) and right-hand (RH) lower forward wing bolt and, if applicable,
removing washer P/N 90-380058-1, inspecting the wing fitting, bolt, and
nut, replacing the wing fitting if it is cracked, and replacing the
washer with washer P/N 90-380019-1. The FAA is issuing this AD to
address the unsafe condition on these products.

DATES: This AD is effective January 11, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of January 11,
2021.

ADDRESSES: For service information identified in this final rule,
contact Textron Aviation Inc., P.O. Box 7706, Wichita, KS 67277; phone:
316-517-5800; internet: https://txtav.com/. You may view this service
information at the FAA, Airworthiness Products Section, Operational
Safety Branch, 901 Locust St., Kansas City, MO 64106. For information
on the availability of this material at the FAA, call 816-329-4148. It
is also available on the internet at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-0718.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.
gov by searching for and locating Docket No. FAA-2020-
0718; 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, any comments received, and other information. The
address for Docket Operations is Docket Operations, 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: Brian C. Adamson, Aviation Safety
Engineer, Wichita ACO Branch, AIR-7K3, FAA, 1801 Airport Rd, Wichita,
KS 67209; phone: 316-946-4193; fax: 316-946-4107; email:
brian.adamson@faa.gov or Wichita-COS@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 certain Textron (type
certificate previously held by Beechcraft Corporation) Models F90, 65-
90, 65-A90, B90, C90, H90 (T-44A), E90, 65-A90-1 (JU-21A, U-21A, RU-
21A, RU-21D, U-21G, RU-21H), 65-A90-2 (RU-21B), 65-A90-3 (RU-21C), 65-
A90-4 (RU-21E, RU-21H), 99, 99A, 99A (FACH), A99, A99A, B99, C99, 100,
A100 (U-21F), and B100 airplanes. The NPRM published in the Federal
Register on July 29, 2020 (85 FR 45545).
The NPRM was prompted by Textron receiving reports of fatigue
cracks in the lower forward wing fitting on two airplanes.
Investigation revealed that installing washer P/N 90-380058-1 on the
wing bolt will cause a premature torque indication. This washer may
have been installed as part of kit 101-4024-3 on Models F90, 65-90, 65-
A90, B90, C90, H90 (T-44A), E90, 65-A90-1 (JU-21A, U-21A, RU-21A, RU-
21D, U-21G, RU-21H), 65-A90-2 (RU-21B), 65-A90-3 (RU-21C), 65-A90-4
(RU-21E, RU-21H), 99, 99A, 99A (FACH), A99, A99A, B99, C99, 100, A100
(U-21F), and B100 airplanes, or as part of kit 90-4077-1 on Models 65-
90, 65-A90, 65-A90-1 (JU-21A, U-21A, RU-21A, RU-21D, U-21G, RU-21H),
65-A90-2 (RU-21B), 65-A90-3 (RU-21C), 65-A90-4 (RU-21E, RU-21H), B90,
C90, and E90 airplanes. Under-torque of the wing bolt causes a reduced
clamping force that changes the load path reacted by the RH and LH
lower forward wing fitting.
In the NPRM, the FAA proposed to require a one-time inspection for
the presence of washer P/N 90-380058-1 on the LH and RH lower forward
wing bolt and, if applicable, removing washer P/N 90-380058-1,
inspecting the wing fitting, bolt, and nut, replacing the wing fitting
if it is cracked, and replacing the washer with washer P/N 90-380019-1.
This condition, if not addressed, could result in fatigue cracks that
lead to failure of the forward lower wing fitting, wing separation, and
loss of airplane control.

Comments

The FAA received one comment from an individual commenter. The
following presents the comment received on the NPRM and the FAA's
response to the comment.

Request Change to Applicability

An individual commenter requested that the AD identify the
applicable airplanes by serial number. The commenter stated that on the
Beech Model C90A serial number LJ[hyphen]1450 airplane, the lower front
wing connections are designed as shear fittings with shear bolts, and
therefore the washers are not affected. The FAA disagrees. The AD, as
proposed, clearly lists the applicable airplane models and serial
numbers. The FAA responded to the commenter by email and advised that
the AD, as proposed, would not apply to the Model C90A. A copy of the
comment and the FAA's response is in the AD docket.

Conclusion

The FAA reviewed the relevant data, considered the comment
received, 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.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Beechcraft Mandatory Service Letter MTL-57-01,
Revision 1, dated September 19, 2018. The service information contains
procedures for a one-time inspection for the presence of washer P/N 90-
380058-1 on the LH and RH lower forward wing bolt and, if applicable,
removing washer P/N 90-380058-1; inspecting the wing fitting, bolt, and
nut; replacing the wing fitting if it is cracked; and replacing the
washer with washer P/N 90-380019-1. 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.

Differences Between This AD and the Service Information

The service information specifies inspecting within 200 flight
hours or 12 months, whichever occurs earlier. This AD would require
inspecting within the next 200 flight hours or 12 months, whichever
occurs later.
The service information applies to Models A100A and A100C
airplanes, and to Model F90 with S/N LA-1. This AD would not apply to
these airplanes because they do not have an FAA type certificate.
This AD would apply to military Models T-44A, JU-21A, RU-21A, RU-
21B, RU-21C, RU-21D, RU-21E, RU-21H, U-21A, U-21F, U-21G, and FACH
airplanes, because these models have a civil counterpart that is
subject to the unsafe condition. The service information does not apply
to all of these military models.

Costs of Compliance

The FAA estimates that this AD will affect 1,319 airplanes of U.S.
registry.
The FAA estimates the following costs to comply with this AD:

Estimated Costs

The FAA estimates the following costs to do any necessary
replacements that would be required based on the results of the
inspection. The FAA has no way of determining the number of airplanes
that might need these replacements:

On-Condition Costs

The FAA has included all known costs in this 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

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.

Adoption of 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: